@article {651854,
	title = {Do sea level variations influence mid-ocean ridge magma supply? A test using crustal thickness and bathymetry data from the East Pacific Rise},
	journal = {Earth and Planetary Science Letters},
	volume = {535},
	year = {2020},
	pages = {116-121},
	abstract = {Recent studies suggest that eustatic sea level fluctuations induced by glacial cycles in the Pleistocene influence mantle-melting and volcanic eruptions at mid-ocean ridges, with models predicting variations in oceanic crustal thickness and seafloor bathymetry linked to sea level change. Analyses of seafloor bathymetry have found evidence of significant spectral energy at frequencies consistent with Milankovi{\'c} cycles of 1/23, 1/41, and 1/80-1/120 ka-1. However, other studies emphasize the need for crustal thickness observations to test the {\textquotedblleft}sea level hypothesis{\textquotedblright}.Here we investigate the hypothesis of climate driven periodicity in mid-ocean ridge magmatism through analysis of a unique bathymetry and crustal thickness dataset derived from a 3D multi-channel seismic investigation of the East Pacific Rise from 9{\textdegree}42{\textquoteright} to 57'N. Crustal thickness data spans the last \~{}235 ka in age and reveals three axis-parallel zones of 200-800 m thicker crust. The amplitude and spacing of these thick crust ridges, which are most prominent on the east flank of the ridge, are consistent with predictions of sea level modulated mantle melting. Similarly spaced ridges are apparent in the longer duration (470 ka) seafloor bathymetry data. Spectral analysis of these datasets shows peaks centered near 1/80 ka-1\&nbsp;and locally near 1/41 ka-1\&nbsp;on the east flank in both bathymetry and crustal thickness. West flank spectral results show intermittent peaks near 1/100 ka-1\&nbsp;and 1/41 ka-1\&nbsp;in crustal thickness and no coherent peak frequencies in bathymetry data. We attribute differences between the east and west flank to the impacts of spatially variable asymmetric spreading and small changes in the locus of accretion. Observed half spreading rates are dominantly faster to the east with small ridge jumps transferring crust from the west flank. Lagged cross-correlations between sea level and crustal thickness indicate a maximum when the latter is lagged by \~{}45 ka, which align thick crust zones with the \~{}100 ka periods of lower sea level. Crustal thickness is also directly compared with seafloor bathymetry, indicating a component of compensated topography with RMS relief at the seafloor of 10 to 29\% of crustal thickness variations. However, complexity inherited from variable asymmetric spreading and seafloor faulting is also apparent, and results provide new insights into how the crustal accretion filter modulates the recording of magma supply variations in the crust and in seafloor relief.While the significance of the statistical analysis of these ridge records is limited by the short duration of the available crustal thickness dataset and effects of asymmetric spreading, the novel observations of crustal thickness varying at timescales of \~{}80-100 ka require a mechanism, and the sea level hypothesis provides a plausible explanation.},
	url = {https://www.sciencedirect.com/science/article/abs/pii/S0012821X20300649},
	author = {B Boulahanis and SM Carbotte and PJ Huybers and MR Nedimovi{\'c} and O Aghaei and JP Canales and Langmuir, C.H.}
}
@article {651853,
	title = {The spatial footprint of hydrothermal scavenging on 230ThXS-derived mass accumulation rates},
	journal = {Geochimica et Cosmochimica Acta},
	year = {2020},
	abstract = {Mid-ocean ridges are valuable archives of sedimentary flux records used to investigate atmospheric, oceanographic, and solid Earth responses to climate variability. Constant flux proxies, such as extraterrestrial helium-3 (3HeET) and excess thorium-230 (230ThXS), constrain vertical mass accumulation rates independent of the biases associated with lateral sediment transport and age model resolution. However, thorium scavenging by hydrothermal particles can perturb local\&nbsp;230ThXS\&nbsp;deposition and complicate its application as a constant flux proxy in near-ridge environments. We characterize the footprint of hydrothermal scavenging on sedimentary\&nbsp;230ThXS\&nbsp;using coupled\&nbsp;3HeET-230ThXS\&nbsp;analyses in cores from the Mid-Atlantic Ridge and the Juan de Fuca Ridge. Samples deposited \&gt;10 km from the Juan de Fuca Ridge indicate reliable off-axis behavior of both constant flux proxies. In contrast, samples deposited \&lt;10 km from the Juan de Fuca Ridge axis and within the axial valley of the Mid-Atlantic Ridge suggest 50{\textendash}80\% deficits in sedimentary\&nbsp;230ThXS\&nbsp;relative to its production rate. These deficits contrast with sedimentary\&nbsp;230ThXS\&nbsp;surpluses recently observed on the East Pacific Rise. The spatial footprint of hydrothermal scavenging varies globally and temporally, likely as a function of the intensity of local hydrothermal activity. The combined ridge data suggest that near-vent sediments (typically within \~{}5 km, but variable by ridge) receive relatively high\&nbsp;230ThXS\&nbsp;deposition rates as a direct result of hydrothermal particle scavenging, while more distal sediments receive relatively low\&nbsp;230ThXS\&nbsp;deposition rates due to diffusive loss of overlying seawater\&nbsp;230ThXS\&nbsp;towards the vent. Aside from the East Pacific Rise, far-field sediments are likely to exhibit typical\&nbsp;230ThXS\&nbsp;deposition rates at distances greater than \~{}10 km of the ridge axis. However,\&nbsp;230ThXS\&nbsp;systematics within the axial valleys of slow-spreading ridges may be complicated by other factors. Combined\&nbsp;3HeET-230ThXS\&nbsp;studies at multiple ridges are needed to further characterize the nature of hydrothermal scavenging and to evaluate the potential of sedimentary\&nbsp;230ThXS\&nbsp;anomalies to record large-scale variability in past hydrothermal activity.},
	url = {https://www.sciencedirect.com/science/article/abs/pii/S0016703720300193},
	author = {Middleton, JL and S. Mukhopadhyay and KM Costa and FJ Pavia and Winckler, G and McManus, JF and M D{\textquoteright}Almeida and Langmuir, C.H. and PJ Huybers}
}
@article {634694,
	title = {Geochemical variability along the northern East Pacific Rise: Coincident source composition and ridge segmentation},
	journal = {Geochemistry, Geophysics, Geosystems},
	year = {2019},
	abstract = {New trace element abundances and isotope compositions for more than 100 mid-ocean ridge basalts from 5.5{\textdegree}N to 19{\textdegree}N on the East Pacific Rise show step function variations in isotopic composition along the ridge axis that coincide with ridge discontinuities. Transform faults, overlapping spreading centers, and devals (deviation from axial linearity) mark the separation of individual clusters of distinct isotopic composition and trace element ratios that indicate source variations. This correlated chemical clustering and morphological segmentation indicates that source composition and segmentation can be closely related even on a fine scale. Substantial chemical variations within a segment are related to source composition. This suggests that even within segments the magma transport is mainly vertical, and there is limited along-ridge transport, and there is little evidence for magma chambers that are well mixed along strike. Trace element concentrations show good correlations with isotopic compositions on a segment scale but less so on a regional scale. The trace element and isotopic variability along the northern East Pacific Rise can be explained by three mantle components: a depleted peridotite endmember, an enriched peridotite endmember, and a recycled gabbro-like component. The gabbroic component has an isotopic signature indicating an ancient origin. The high-resolution sampling indicates that within a segment the chemical variability is largely binary but that the endmembers of the binary mixing change from segment to segment. The endmembers of the binary variation within a segment are a combination of three of the endmembers.},
	url = {https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2019GC008287},
	author = {Mallick, S. and Salters, V.J.M. and Langmuir, C.H.}
}
@article {634693,
	title = {An isotopically distinct Zealandia{\textendash}Antarctic mantle domain in the Southern Ocean},
	journal = {Nature Geoscience},
	volume = {12},
	number = {3},
	year = {2019},
	pages = {206-214},
	abstract = {Article\&nbsp;|\&nbsp;Published:\&nbsp;28 January 2019An isotopically distinct Zealandia{\textendash}Antarctic mantle domain in the Southern OceanSung-Hyun Park,\&nbsp;Charles H. Langmuir,\&nbsp;Kenneth W. W. Sims,\&nbsp;Janne Blichert-Toft,\&nbsp;Seung-Sep Kim,\&nbsp;Sean R. Scott,\&nbsp;Jian Lin,\&nbsp;Hakkyum Choi,\&nbsp;Yun-Seok Yang\&nbsp;\&amp;\&nbsp;Peter J. Michael\&nbsp;Nature Geosciencevolume\&nbsp;12,\&nbsp;pages206{\textendash}214\&nbsp;(2019)\&nbsp;|\&nbsp;Download CitationAbstractThe mantle sources of mid-ocean ridge basalts beneath the Indian and Pacific oceans have distinct isotopic compositions with a long-accepted boundary at the Australian{\textendash}Antarctic Discordance along the Southeast Indian Ridge. This boundary has been widely used to place constraints on large-scale patterns of mantle flow and composition in the Earth{\textquoteright}s upper mantle. Sampling between the Indian and Pacific ridges, however, has been lacking, especially along the remote 2,000 km expanse of the Australian{\textendash}Antarctic Ridge. Here we present Sr, Nd, Hf and Pb isotope data from this region that show the Australian{\textendash}Antarctic Ridge has isotopic compositions distinct from both the Pacific and Indian mantle domains. These data define a separate Zealandia{\textendash}Antarctic domain that appears to have formed in response to the deep mantle upwelling and ensuing volcanism that led to the break-up of Gondwana 90 million years ago, and currently persists at the margins of the Antarctic continent. The relatively shallow depths of the Australian{\textendash}Antarctic Ridge may be the result of this deep mantle upwelling. Large offset transforms to the east may be the boundary with the Pacific domain.},
	url = {https://www.nature.com/articles/s41561-018-0292-4},
	author = {Park, SH and Langmuir, C.H. and K. W. W. Sims and Blichert-Toft, J and S.S. Kim and Scott, SR and Lin, J and Choi, H and Yang, YS and Michael, P.J.}
}
@article {634700,
	title = {Vanadium isotope compositions of mid-ocean ridge lavas and altered oceanic crust},
	journal = {Earth and Planetary Science Letters},
	volume = {493},
	year = {2018},
	pages = {128-139},
	abstract = {Vanadium isotope compositions of igneous rocks have the potential to constrain variations of physico-chemical conditions such as oxidation states during magmatism. Here, we present V isotope data for 27 fresh lavas (ranging from basaltic to dacitic compositions) from mid-ocean ridges, 31 altered basalts and gabbros from IODP site 1256 near the East Pacific Rise (EPR), and 2 back arc basin basalts (BABB). Our analyses of fresh mid-ocean ridge basalt (MORB) provide new constraints on the V isotope composition of MORBs, i.e.\&nbsp;{\textperthousand}δ51V=-0.84{\textpm}0.02{\textperthousand}\&nbsp;(2SE,\&nbsp;n=22). In addition, the mean\&nbsp;δ51V\&nbsp;of MORBs from individual segments is correlated with the mean ridge depth and Na8.0\&nbsp;of the segment, which might reflect the effect of melting extent on V isotope fractionation during mantle melting.The mafic profile of intact altered oceanic crust (AOC) from the IODP site 1256 has\&nbsp;δ51V ranging from -1.01 to\&nbsp;{\textperthousand}-0.77{\textperthousand}, similar to that of fresh MORBs, suggesting that V isotope fractionation is limited during alteration of oceanic crust. These results also indicate the V isotopic homogeneity of the bulk oceanic crust with average\&nbsp;δ51V of\&nbsp;{\textperthousand}-0.85{\textpm}0.02{\textperthousand}\&nbsp;(2SE,\&nbsp;n=53), which is unaffected by ocean water and hydrothermal fluid alteration. Our results provide a guideline for application of V isotopes into studies of low and high temperature geochemical processes.The evolved lavas (basaltic andesites, andesites, and dacites) from the East Pacific Rise (EPR) show apparent shifts towards heavy\&nbsp;δ51V values with increasing degree of differentiation, which can be explained by the crystal{\textendash}liquid fractionation during crystallization with an inferred isotope fractionation factor of\&nbsp;Δ51Vmineral-melt=-0.15{\texttimes}106/T2. The enrichment of\&nbsp;51V with increasing differentiation degree for the 9{\textdegree}N Overlapping Spreading Center (OSC) lavas is consistent with direction of the isotope shift observed in lavas from Anatahan Island (Northern Mariana Arc) and Hekla Volcano (Iceland), but the magnitude (0.3{\textperthousand}) is much smaller than that (2{\textperthousand}) reported in\&nbsp;Prytulak et al. (2017). Modeling of V isotope fractionation between mineral and melt shows that variations in redox condition are important for controlling V isotope fractionation, but insufficient to explain the dramatically different\&nbsp;Δ51Vmineral-melt\&nbsp;between 9{\textdegree}N OSC lavas and Anatahan/Hekla suites. More studies are necessary for better understanding of mechanisms of V isotope fractionation during magmatism.},
	url = {https://www.sciencedirect.com/science/article/pii/S0012821X18302048},
	author = {Wu, F and Qi, Y and Perfit, MR and Gao, Y and Langmuir, C.H. and Wanless, VD and Yu, H and Huang, F}
}
@article {634699,
	title = {Petrogenesis of the Late Mesozoic Magnesian and Ferroan Granites in Northwest Zhejiang, Southeast China, and Their Implications},
	journal = {The Journal of Geology},
	volume = {126},
	number = {4},
	year = {2018},
	pages = {407-425},
	abstract = {Northwest Zhejiang Province (NWZJ) is located in the southeastern Lower Yangtze River Belt, southeastern China. Here we document the occurrence of both magnesian (149{\textendash}131 Ma) and ferroan (162{\textendash}121 Ma) granitoids in NWZJ. The magnesian granitoids are calc-alkalic peraluminous in composition, with a wide range of SiO2(58{\textendash}72 wt\%) contents. They have high K2O/Na2O, Sr/Y, and (La/Yb)N\&nbsp;ratios, with insignificant Eu anomalies, whereas the calc-alkalic peraluminous ferroan granites have high SiO2\&nbsp;(76{\textendash}77 wt\%) contents, Fe indices (FeO*/(FeO*+MgO)FeO*/(FeO*+MgO)), and Ga/Al ratios. The ferroan granites also have low Ce/Pb and Nb/U ratios, with strong Ba, Sr, and Eu negative anomalies. Most of the rocks have similar zircon Lu-Hf isotopes (εHf(t)=-6.0εHf(t)=-6.0\&nbsp;to -0.7). However, rocks from two ferroan granitic bodies (Huangshitan and Jiuligang) have more depleted Hf isotopes, with εHf(t) ranging from -1.9 to 5.9. The whole-rock Nd isotopes of the ferroan granites (εNd(t)=-6.5εNd(t)=-6.5\&nbsp;to -3.2) are slightly more depleted than those of magnesian granitoids (εNd(t)=-8.8εNd(t)=-8.8\&nbsp;to -5.1). In addition, all ferroan granites show similar and high present-day whole-rock Pb isotopic ratios (18.3{\textendash}18.8 for\&nbsp;206Pb/204Pb, 15.6{\textendash}15.7 for\&nbsp;207Pb/204Pb, and 38.5{\textendash}39.0 for\&nbsp;208Pb/204Pb). On the basis of published data and our new results, we propose that the magnesian granitoids were generated by partial melting of lower-crustal materials, whereas the ferroan granites were derived from a similar source but some more-depleted materials were added into their source after \~{}135 Ma. The water contents of the magma may have played an important role in determining the different geochemical affinities of the felsic magmatism. The felsic magmatism occurred under an extensional setting during the period 162{\textendash}121 Ma. The extension of the lithosphere was further enhanced and followed by upwelling of asthenospheric mantle after \~{}135 Ma. This study suggests that a change in the tectonic regime occurred at \~{}135 Ma in NWZJ, which may have been triggered by the rollback of the subducted Paleo-Pacific Plate.},
	url = {https://www.journals.uchicago.edu/doi/pdfplus/10.1086/697691},
	author = {Wu, T and Li, ZL and Zhou, J. and Mao, J-R and Langmuir, C.H. and Wang, C-L and Zhang, F-J and X Gao and Chen, R. and Lin, Q-L and Y. Zhang and Kamei, A}
}
@article {634698,
	title = {Trace element (Mn, Zn, Ni, V) and authigenic uranium (aU) geochemistry reveal sedimentary redox history on the Juan de Fuca Ridge, North Pacific Ocean},
	journal = {Geochimica et Cosmochimica Acta},
	number = {236},
	year = {2018},
	pages = {79-98},
	abstract = {Changes in meridional overturning circulation and water mass chemistry can be recorded by oxygen concentrations in the deep ocean. Because the deep Pacific is the largest ocean reservoir, its oxygen concentrations may be related to global climate change. In this study, oxygen conditions in the past are reconstructed by contrasting the\&nbsp;sedimentary geochemistry\&nbsp;of multiple redox-sensitive\&nbsp;trace elements\&nbsp;(Mn, Ni, Zn, V corrected for terrigenous and hydrothermal inputs) and authigenic U (aU) from six\&nbsp;sediment cores\&nbsp;on the Juan de Fuca Ridge from 2.7-2.8 km depth. We find that Mn and Ni are indicators for oxygen-rich conditions, while Zn, V, and aU are indicators for oxygen-poor conditions. Relative\&nbsp;Redox Potentials\&nbsp;(RRPs) for each core are calculated by converting excess metal fluxes into binary presence/absence designations, weighting each element by the strength and direction of its redox indication, summing the five elements, and then averaging the data in 5kyr bins. Metal depositional histories from all six cores demonstrate low oxygen conditions during\&nbsp;interglacial\&nbsp;periods, particularly during 100{\textendash}120 ka (MIS5) but also 200{\textendash}250 ka (MIS7), and high oxygen conditions during glacial periods (MIS2-4 and MIS6). This redox pattern does not appear to be driven by organic matter flux to the sediment, as reconstructed by three different paleo-productivity proxies (organic carbon, opal, and excess barium). Instead higher oxygen concentrations on the Juan de Fuca Ridge may be a result of better ventilation during glacial periods, possibly due to enhanced North Pacific\&nbsp;Intermediate Waterformation. Alternatively, sedimentary\&nbsp;redox conditions\&nbsp;on the Juan de Fuca Ridge may be locally controlled by the deposition of hydrothermal sulfides from nearby vent fields.},
	url = {https://www.sciencedirect.com/science/article/pii/S0016703718300863},
	author = {Kosta, KM and Anderson, RF and McManus, JF and Winckler, G and Middleton, JL and Langmuir, C.H.}
}
@article {634697,
	title = {Carbon Fluxes and Primary Magma CO2 Contents Along the Global Mid-Ocean Ridge System},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {20},
	number = {3},
	year = {2018},
	abstract = {The concentration of carbon in primary mid-ocean ridge basalts (MORBs), and the associated fluxes of CO2\&nbsp;outgassed at ocean ridges, is examined through new data obtained by secondary ion mass spectrometry (SIMS) on 753 globally distributed MORB glasses. MORB glasses are typically 80{\textendash}90\% degassed of CO2. We thus use the limited range in CO2/Ba (81.3\&nbsp;{\textpm}\&nbsp;23) and CO2/Rb (991\&nbsp;{\textpm}\&nbsp;129), derived from undegassed MORB and MORB melt inclusions, to estimate primary CO2\&nbsp;concentrations for ridges that have Ba and/or Rb data. When combined with quality-controlled volatile-element data from the literature (n\&nbsp;=\&nbsp;2,446), these data constrain a range of primary CO2\&nbsp;abundances that vary from 104\&nbsp;ppm to 1.90\&nbsp;wt\%. Segment-scale data reveal a range in MORB magma flux varying by a factor of 440 (from 6.8\&nbsp;{\texttimes}\&nbsp;105\&nbsp;to 3.0\&nbsp;{\texttimes}\&nbsp;108\&nbsp;m3/year) and an integrated global MORB magma flux of 16.5\&nbsp;{\textpm}\&nbsp;1.6\&nbsp;km3/year. When combined with CO2/Ba and CO2/Rb-derived primary magma CO2\&nbsp;abundances, the calculated segment-scale CO2\&nbsp;fluxes vary by more than 3 orders of magnitude (3.3\&nbsp;{\texttimes}\&nbsp;107\&nbsp;to 4.0\&nbsp;{\texttimes}\&nbsp;1010\&nbsp;mol/year) and sum to an integrated global MORB CO2\&nbsp;flux of\&nbsp;\&nbsp;{\texttimes}\&nbsp;1012\&nbsp;mol/year. Variations in ridge CO2\&nbsp;fluxes have a muted effect on global climate; however, because the vast majority of CO2degassed at ridges is dissolved into seawater and enters the marine bicarbonate cycle. MORB degassing would thus only contribute to long-term variations in climate via degassing directly into the atmosphere in shallow-water areas or where the ridge system is exposed above sea level.Plain Language SummaryEstimated CO2\&nbsp;contents of primary mid-ocean ridge basalts (MORB), calculated on a segment-by-segment basis, vary from 104\&nbsp;ppm to 1.9\&nbsp;wt\%. CO2-enriched MORB are present in all ocean basins, in particular, in the Atlantic Ocean basin, which is younger and more likely to contain admixed material from recent subduction compared to the much older Pacific Ocean basin. CO2\&nbsp;fluxes at individual ridge segments vary by 3 orders of magnitude due primarily to large variability in primary CO2\&nbsp;content. This study provides the most detailed and accurate estimate to date of the integrated total flux of CO2\&nbsp;from mid-ocean ridges of\&nbsp;\&nbsp;{\texttimes}\&nbsp;1012\&nbsp;mol/year.},
	url = {https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018GC007630},
	author = {Le Voyer, M and E. H. Hauri and Cottrell, E and Kelley, K and Salters, V.J.M. and Langmuir, C.H. and Hilton, DR and Barry, PH and F{\"u}ri, E}
}
@article {MIDDLETON201812,
	title = {Millennial-scale variations in dustiness recorded in Mid-Atlantic sediments from 0 to 70 ka},
	journal = {Earth and Planetary Science Letters},
	volume = {482},
	year = {2018},
	pages = {12 - 22},
	abstract = {Sedimentary records of dust deposition in the subtropical Atlantic provide important constraints on millennial- and orbital-scale variability in atmospheric circulation and North African aridity. Constant flux proxies, such as extraterrestrial helium-3, yield dust flux records that are independent of the biases caused by lateral sediment transport and limited resolution that may be associated with age-model-derived mass accumulation rates. However, Atlantic dust records constrained using constant flux proxies are sparsely distributed and generally limited to the past 20 ka. Here we extend the Atlantic record of North African dust deposition to 70 ka using extraterrestrial helium-3 and measurements of titanium, thorium, and terrigenous helium-4 in two sediment cores collected at 26{\textdegree}N and 29{\textdegree}N on the Mid-Atlantic Ridge and compare results to model estimates for dust deposition in the subtropical North Atlantic. Dust proxy fluxes between 26{\textdegree}N and 29{\textdegree}N are well correlated, despite variability in lateral sediment transport, and underscore the utility of extraterrestrial helium-3 for constraining millennial-scale variability in dust deposition. Similarities between Mid-Atlantic dust flux trends and those observed along the Northwest African margin corroborate previous interpretations of dust flux variability over the past 20 ka and suggest that long distance transport and depositional processes do not overly obscure the signal of North African dust emissions. The 70 ka Mid-Atlantic record reveals a slight increase in North African dustiness from Marine Isotope Stage 4 through the Last Glacial Maximum and a dramatic decrease in dustiness associated with the African Humid Period. On the millennial-scale, the new records exhibit brief dust maxima coincident with North Atlantic cold periods such as the Younger Dryas, and multiple Heinrich Stadials. The correlation between Mid-Atlantic dust fluxes and previous constraints on North African aridity is high. However, precipitation exerts less control on dust flux variability prior to the African Humid Period, when wind variability governs dust emissions from consistently dry dust source regions. Thus, the Mid-Atlantic dust record supports the hypothesis that both aridity and wind strength drive dust flux variability across changing climatic conditions.},
	keywords = {helium-3, mass accumulation rate, mineral dust, North Africa, Subtropical North Atlantic, thorium-232},
	issn = {0012-821X},
	doi = {https://doi.org/10.1016/j.epsl.2017.10.034},
	url = {http://www.sciencedirect.com/science/article/pii/S0012821X17306027},
	author = {Jennifer L. Middleton and Sujoy Mukhopadhyay and Charles H. Langmuir and Jerry F. McManus and Peter J. Huybers}
}
@conference {Ferguson2017A6K,
	title = {A 65  k.y . time series from sediment-hosted glasses reveals rapid transitions in ocean ridge magmas},
	year = {2017},
	note = {This paper established the first time series of ocean ridge basalt compositions using sediment hosted glasses on old ocean crust.},
	author = {David J. Ferguson and Li, Ying and Charles H. Langmuir and Kassandra M. Costa and Jerry F. McManus and Peter J Huybers and Suzanne Carbotte}
}
@article {HUYBERS2017238,
	title = {Delayed CO2 emissions from mid-ocean ridge volcanism as a possible cause of late-Pleistocene glacial cycles},
	journal = {Earth and Planetary Science Letters},
	volume = {457},
	year = {2017},
	pages = {238 - 249},
	abstract = {The coupled 100,000 year variations in ice volume, temperature, and atmospheric CO2 during the late Pleistocene are generally considered to arise from a combination of orbital forcing, ice dynamics, and ocean circulation. Also previously argued is that changes in glaciation influence atmospheric CO2 concentrations through modifying subaerial volcanic eruptions and CO2 emissions. Building on recent evidence that ocean ridge volcanism responds to changes in sea level, here it is suggested that ocean ridges may play an important role in generating late-Pleistocene 100 ky glacial cycles. If all volcanic CO2 emissions responded immediately to changes in pressure, subaerial and ocean-ridge volcanic emissions anomalies would oppose one another. At ocean ridges, however, the egress of CO2 from the mantle is likely to be delayed by tens-of-thousands of years, or longer, owing to ascent time. A simple model involving temperature, ice, and CO2 is presented that oscillates at \~{}100 ky time scales when incorporating a delayed CO2 contribution from ocean ridge volcanism, even if the feedback accounts for only a small fraction of total changes in CO2. Oscillations readily become phase-locked with insolation forcing associated with changes in Earth{\textquoteright}s orbit. Under certain parameterizations, a transition from \~{}40 ky to larger \~{}100 ky oscillations occurs during the middle Pleistocene in response to modulations in orbital forcing. This novel description of Pleistocene glaciation should be testable through ongoing advances in understanding the circulation of carbon through the solid earth.},
	keywords = {glacial cycles, Pleistocene, volcanism},
	issn = {0012-821X},
	doi = {https://doi.org/10.1016/j.epsl.2016.09.021},
	url = {http://www.sciencedirect.com/science/article/pii/S0012821X16305015},
	author = {Huybers, Peter and Charles H. Langmuir}
}
@article {TURNER2017216,
	title = {The importance of mantle wedge heterogeneity to subduction zone magmatism and the origin of EM1},
	journal = {Earth and Planetary Science Letters},
	volume = {472},
	year = {2017},
	pages = {216 - 228},
	abstract = {The composition of the convecting asthenospheric mantle that feeds the mantle wedge can be investigated via rear-arc lavas that have minimal slab influence. This {\textquotedblleft}ambient mantle wedge{\textquotedblright} composition (the composition of the wedge prior to the addition of a slab component) varies substantially both worldwide and within individual arcs. 143Nd/144Nd measurements of rear-arc samples that have minimal slab influence are similar to 143Nd/144Nd in the stratovolcanoes of the adjacent volcanic fronts, suggesting that 143Nd/144Nd of arc-front volcanics are largely inherited from the ambient mantle composition. 143Nd/144Nd correlates with ratios such as Th/U, Zr/Nb, and La/Sm, indicating that these ratios also are strongly influenced by ambient wedge heterogeneity. The same phenomenon is observed among individual volcanoes from the Chilean Southern Volcanic Zone (SVZ), where along-strike variability of the volcanic front tracks that of rear-arc monogenetic volcanics. Depleted mantle wedges are more strongly influenced by slab-derived components than are enriched wedges. This leads to surprising trace element correlations in the global dataset, such as between Pb/Nb and Zr/Nb, which are not explicable by variable compositions or fluxes of slab components. Depleted ambient mantle is present beneath arcs with back-arc spreading; relatively enriched mantle is present adjacent to continents. Ambient mantle wedge heterogeneity both globally and regionally forms isotope mixing trajectories for Sr, Nd and Hf between depleted mantle and EM1-type enriched compositions as represented by Gough Island basalts. Making use of this relationship permits a quantitative match with the SVZ data. It has been suggested that EM1-type mantle reservoirs are the result of recycled lower continental crust, though such models do not account for certain trace element ratios such as Ce/Pb and Nb/U or the surprisingly homogeneous trace element compositions of EM1 volcanics. A model in which the EM1 end-member found in continental arcs is produced by low-degree melt-metasomatism of the sub-continental lithospheric mantle may be more plausible. The 143Nd/144Nd maximum along the SVZ may be a consequence of either rifting and collision of two ancient lithospheric domains or a slab tear. The correspondence of mantle wedge variations with EM1 suggests a potential role for metasomatized sub-continental lithosphere in creating EM1 sources globally.},
	keywords = {ambient, EM1, Heterogeneity, mantle, subduction, SVZ},
	issn = {0012-821X},
	doi = {https://doi.org/10.1016/j.epsl.2017.04.051},
	url = {http://www.sciencedirect.com/science/article/pii/S0012821X17302467},
	author = {Stephen J. Turner and Charles H. Langmuir and Michael A. Dungan and Stephane Escrig}
}
@article {COSTA2017120,
	title = {Hydrothermal deposition on the Juan de Fuca Ridge over multiple glacial{\textendash}interglacial cycles},
	journal = {Earth and Planetary Science Letters},
	volume = {479},
	year = {2017},
	pages = {120 - 132},
	abstract = {Hydrothermal systems play an important role in modern marine chemistry, but little is known about how they may have varied on 100,000 year timescales. Here we present high-resolution records of non-lithogenic metal fluxes within sediment cores covering the last 500,000 years of hydrothermal deposition on the flanks of the Juan de Fuca Ridge. Six adjacent, gridded cores were analyzed by x-ray fluorescence for Fe, Mn, and Cu concentrations, corrected for lithogenic inputs with Ti, and normalized to excess initial 230Th to generate non-lithogenic metal flux records that provide the longest orbitally resolved reconstructions of hydrothermal activity currently available. Fe fluxes vary with global sea level over the last two glacial cycles, suggesting higher hydrothermal deposition during interglacial periods. The observed negative relationship between Fe and Mn indicates variable sediment redox conditions and diagenetic remobilization of sedimentary Mn over time. Thus, Mn fluxes may not be a reliable indicator for hydrothermal activity in the Juan de Fuca Ridge sediment cores. Cu fluxes show substantial high-frequency variability that may be linked to changes in vent temperature related to increased magmatic production during glacial periods. Deglacial hydrothermal peaks on the Juan de Fuca Ridge are consistent with previously published records from the Mid-Atlantic Ridge and the East Pacific Rise. Moreover, on the Juan de Fuca Ridge, the deglacial peaks in hydrothermal activity are followed by relatively high hydrothermal fluxes throughout the ensuing interglacial periods relative to the previous glacial period.},
	keywords = {Copper, hydrothermal activity, Iron, Juan de Fuca Ridge},
	issn = {0012-821X},
	doi = {https://doi.org/10.1016/j.epsl.2017.09.006},
	url = {http://www.sciencedirect.com/science/article/pii/S0012821X17305010},
	author = {Kassandra M. Costa and Jerry F. McManus and Jennifer L. Middleton and Charles H. Langmuir and Peter J. Huybers and Gisela Winckler and Sujoy Mukhopadhyay}
}
@article {622390,
	title = {Light Stable Isotopic Compositions of Enriched Mantle Sources:Resolving the Dehydration Paradox},
	journal = {Goechemistry Geophysics Geosystems},
	year = {2017},
	author = {Dixon et al}
}
@article {631702,
	title = {Estimating the Parental Magma Composition and Temperature of the Xiaohaizi Cumulate-Bearing Ultramafic Rock: Implication for Magma Evolution of the Tarim Large Igneous Province, Northwestern China },
	journal = {Journal of Earth Science},
	volume = {27},
	number = {3},
	year = {2016},
	pages = {519{\textendash}528},
	author = {Sun, H. and Li, Y. and Li, Z. and Zou, S. and Langmuir, C.H and Chen, H. and Yang1, S and Ren, Z}
}
@article {631633,
	title = {Importance of the thermal structure of the mantle wedge to global arc lava compositions.},
	journal = {Nature Geoscience},
	volume = {9},
	year = {2016},
	pages = {772{\textendash}776},
	author = {Dungan, S. and Turney, C and Katz, R.F and Langmuir, C.H and Turner, S.J}
}
@article {Turner2016,
	title = {Parental arc magma compositions dominantly controlled by mantle-wedge thermal structure},
	journal = {Nature Geoscience},
	volume = {9},
	year = {2016},
	month = {Aug},
	pages = {772 EP -},
	publisher = {Nature Publishing Group SN -},
	url = {https://doi.org/10.1038/ngeo2788},
	author = {Stephen J. Turner and Charles H. Langmuir and Richard F. Katz and Michael A. Dungan and St{\'e}phane Escrig}
}
@article {COSTA2016163,
	title = {Sedimentation, stratigraphy and physical properties of sediment on the Juan de Fuca Ridge},
	journal = {Marine Geology},
	volume = {380},
	year = {2016},
	pages = {163 - 173},
	abstract = {Sedimentation near mid-ocean ridges may differ from pelagic sedimentation due to the influence of the ridges{\textquoteright} rough topography on sediment deposition and transport. This study explores whether the near-ridge environment responds to glacial-interglacial changes in climate and oceanography. New benthic δ18O, radiocarbon, multi-sensor track, and physical property (sedimentation rates, density, magnetic susceptibility) data for seven cores on the Juan de Fuca Ridge provide multiple records covering the past 700,000years of oceanographic history of the Northeast Pacific Ocean. Systematic variations in sediment density and coarse fraction correspond to glacial-interglacial cycles identified in benthic δ18O, and these observations may provide a framework for mapping the δ18O chronostratigraphy via sediment density to other locations on the Juan de Fuca Ridge and beyond. Sedimentation rates generally range from 0.5 to 3cm/kyr, with background pelagic sedimentation rates close to 1cm/kyr. Variability in sedimentation rates close to the ridge likely reflects remobilization of sediment caused by the high relief of the ridge bathymetry. Sedimentation patterns primarily reflect divergence of sedimentation rates with distance from the ridge axis and glacial-interglacial variation in sedimentation that may reflect carbonate preservation cycles as well as preferential remobilization of fine material.},
	keywords = {Juan de Fuca Ridge, Oxygen isotope stratigraphy, Sediment density, Sedimentation rates},
	issn = {0025-3227},
	doi = {https://doi.org/10.1016/j.margeo.2016.08.003},
	url = {http://www.sciencedirect.com/science/article/pii/S0025322716301517},
	author = {K.M. Costa and J.F. McManus and B. Boulahanis and S.M. Carbotte and G. Winckler and P.J. Huybers and Langmuir, C.H.}
}
@article {631696,
	title = {What processes control the chemical compositions of arc front stratovolcanoes?},
	journal = {Geochem. Geophys. Geosys., doi: 10.1002/2014GC005633},
	year = {2015},
	author = {Turner, S.J and Langmuir, C.H.}
}
@article {Crowley2015ResponseTC,
	title = {Response to Comment on {\textquotedblleft}Glacial cycles drive variations in the production of oceanic crust{\textquotedblright}},
	journal = {Science},
	volume = {349},
	year = {2015},
	pages = {1065-1065},
	author = {John W. Crowley and Richard F. Katz and Peter J Huybers and Charles H. Langmuir and Sung-Hyun Park}
}
@article {Crowley2015GlacialCD,
	title = {Glacial cycles drive variations in the production of oceanic crust},
	journal = {Science},
	volume = {347},
	year = {2015},
	pages = {1237-1240},
	author = {John W. Crowley and Richard F. Katz and Peter J Huybers and Charles H. Langmuir and Sung-Hyun Park}
}
@article {TURNER2015182,
	title = {The global chemical systematics of arc front stratovolcanoes: Evaluating the role of crustal processes},
	journal = {Earth and Planetary Science Letters},
	volume = {422},
	year = {2015},
	pages = {182 - 193},
	abstract = {Petrogenetic models for convergent margins should be consistent with the global systematics of convergent margin volcanic compositions. A newly developed tool for compiling and screening data from the GEOROC database was used to generate a global dataset of whole rock chemical analyses from arc front stratovolcano samples. Data from 227 volcanoes within 31 volcanic arc segments were first averaged by volcano and then by arc to explore global systematics. Three different methods of data normalization produce consistent results that persist across a wide range of Mg$\#$ [Mg$\#$=Mg/(Mg+Fe)]. Remarkably coherent systematics are present among major and trace element concentrations and ratios, with the exception of three arcs influenced by mantle plumes and Peru/N. Chile, which is built on exceptionally thick crust. Chemical parameters also correlate with the thickness of the overlying arc crust. In addition to previously established correlations of Na6.0 with Ca6.0 and crustal thickness, correlations are observed among major elements, trace elements, and trace element ratios (e.g. La/Yb, Dy/Yb, Zr/Sm, Zr/Ti). Positive correlations include {\textquotedblleft}fluid mobile,{\textquotedblright} {\textquotedblleft}high field strength,{\textquotedblright} and {\textquotedblleft}large ion lithophile{\textquotedblright} element groups, with concentrations that vary by a factor of five in all groups. Incompatible element enrichments also correlate well with crustal thickness, with the greatest enrichment found at arcs with the thickest crust. Intra-crustal processes, however, do not reproduce the global variations. High pressure fractionation produces intermediate magmas enriched in aluminum, but such magmas are rare. Furthermore, differences among magma compositions at various volcanic arcs persist from primitive to evolved compositions, which is inconsistent with the possibility that global variations are produced by crystal fractionation at any pressure. Linear relationships among elements appear to be consistent with mixing between depleted primary magma and an enriched contaminant, but the required composition of the theoretical enriched end-member is not similar to compositions expected in the deep crust or to any known rock composition. The large-scale chemical variations among volcanic arcs are therefore likely to be generated by processes in the subducting slab or mantle wedge, rather than the crust. While crustal processes are important in the differentiation of convergent margin magmas, they do not account for the systematics presented here. Models that attribute the chemical variability of arc magmas to slab or wedge processes are also constrained to be consistent with the global chemical systematics, and are discussed in Turner and Langmuir (2015).},
	keywords = {arc, chemistry, Global, petrology, subduction, volcano},
	issn = {0012-821X},
	doi = {https://doi.org/10.1016/j.epsl.2015.03.056},
	url = {http://www.sciencedirect.com/science/article/pii/S0012821X15002228},
	author = {Stephen J. Turner and Charles H. Langmuir}
}
@article {LAUBIER2014265,
	title = {Trace element mineral/melt partitioning for basaltic and basaltic andesitic melts: An experimental and laser ICP-MS study with application to the oxidation state of mantle source regions},
	journal = {Earth and Planetary Science Letters},
	volume = {392},
	year = {2014},
	pages = {265 - 278},
	abstract = {Understanding magmatic processes such as crystallization and melting recorded in natural samples requires calibration of mineral{\textendash}melt trace element partition coefficients (D) and their dependence on temperature, pressure, oxygen fugacity (fO2) and chemical composition. However, few experimental studies have focused on measuring trace element partition coefficients for a large number of trace elements, in the various minerals present in basaltic rocks, and under diverse conditions, particularly of variable fO2. Twenty-seven 0.1 MPa experiments provide partition coefficients for major elements and Sc, Ti, V, Mn, Co, Ni, Ga, Sr, Y, Nb, Ba, Ce, Nd, Eu, Gd, and Yb for the mineral phases olivine, plagioclase, orthopyroxene and clinopyroxene. The experimental conditions range from 1150 to 1190 {\textdegree}C with oxygen fugacities from QFM to NNO+2. Run products were analyzed by laser-ablation ICP-MS. The new partition coefficients, combined with previously published data, can be used to model crystallization processes at low pressure. Partitioning of multivalent cations V, Fe and Eu varies as a function of the redox conditions, consistent with previous work, and can be used to constrain oxidation states of magmatic source regions. The V/Yb ratio is shown to be a useful proxy for oxidation state. The V/Yb ratio varies during mantle melting as a function of oxidation state of the mantle source, and it is not modified during fractional crystallization of olivine {\textpm} plag {\textpm} cpx. V/Yb increases from MORB, BABB to arc lavas, suggesting a progressive increase of fO2 from QFM to NNO+2. Apparent fO2 of arc lavas, however, is quite variable. These results demonstrate that sub-arc mantle displays a larger range of redox conditions toward a more oxidized mantle than the MORB mantle.},
	keywords = {arc magmas, mantle, MORB, oxygen fugacity, partitioning, Trace Elements},
	issn = {0012-821X},
	doi = {https://doi.org/10.1016/j.epsl.2014.01.053},
	url = {http://www.sciencedirect.com/science/article/pii/S0012821X14000697},
	author = {Muriel Laubier and Timothy L. Grove and Charles H. Langmuir}
}
@article {RAY2014188,
	title = {A common parentage for Deccan Continental Flood Basalt and Central Indian Ocean Ridge Basalt? A geochemical and isotopic approach},
	journal = {Journal of Asian Earth Sciences},
	volume = {84},
	year = {2014},
	note = {FLOOD BASALTS OF ASIA},
	pages = {188 - 200},
	abstract = {A comparison of geochemical and Sr{\textendash}Nd{\textendash}Pb isotopic compositions for Deccan Continental Flood Basalts (CFBs) and Central Indian Ridge (CIR) Basalts is presented: these data permit assessment of possible parental linkages between the two regions, and comparison of their respective magmatic evolutionary trends in relation to rift-related tectonic events during Gondwana break-up. The present study reveals that Mid-Ocean Ridge Basalt (MORB) from the northern CIR and basalts of Deccan CFB are geochemically dissimilar because of: (1) the Deccan CFB basalts typically show a greater iron-enrichment as compared to the northern CIR MORB, (2) a multi-element spiderdiagram reveals that the Deccan CFBs reveal a more fractionated slope (Ba/YbN>1), as compared to relatively flat northern CIR MORB (Ba/YbN,
	keywords = {CIR MORB, Deccan CFB, Lower continental crust, Petrogenesis, Upper continental crust},
	issn = {1367-9120},
	doi = {https://doi.org/10.1016/j.jseaes.2013.12.015},
	url = {http://www.sciencedirect.com/science/article/pii/S1367912013006445},
	author = {Ray, D. and S. Misra and M. Widdowson and Langmuir, C.H.}
}
@article {LI201447,
	title = {Origin of the Early Permian zircons in Keping basalts and magma evolution of the Tarim Large Igneous Province (northwestern China)},
	journal = {Lithos},
	volume = {204},
	year = {2014},
	note = {Special Issue Permian large igneous provinces: Characteristics, mineralization and paleo-environment effects},
	pages = {47 - 58},
	abstract = {The Tarim continental flood basalts (CFBs) provide important clues about the genesis and magmatic evolution of the Early Permian Tarim Large Igneous Province (Tarim LIP) in northwestern China. Here we present results of LA{\textendash}MC{\textendash}ICPMS Lu{\textendash}Hf isotope analysis on Early Permian (ca. 290Ma) zircons extracted from the Tarim CFBs in the Keping area, northwest of the Tarim Basin. Zircons from two sub-groups of Keping basalts (Groups 1a and 1b) have similar Lu{\textendash}Hf isotopic compositions and exhibit a relatively large range of 176Hf/177Hf ratios between 0.282422 and 0.282568. Their negative εHf(t) values (-6.8{\textendash}-1.4) are generally lower than the whole-rock εHf(t) values of their host basalts (-2.8{\textendash}2.1), and are distinct from other known intrusive rocks (-0.3{\textendash}7.1) in the Tarim LIP and their hosted zircons (4.9{\textendash}8.8). Systematic studies of Hf isotopic data from Tarim and its adjacent regions reveal that these zircons are probably xenocrysts, sourced from coeval igneous rocks in the South Tianshan Orogen (e.g., the Lower Permian Xiaotikanlike Formation volcanic and pyroclastic rock suite). This, together with the presence of Precambrian zircons in Keping basalts, clearly indicates crustal contamination during their eruptions and provides hints about the potential contaminant sources. Geochemical modeling further suggests that the earlier erupted Group 1b basalts experienced more contamination, predominantly by some high Th{\textendash}U{\textendash}Pb rock components, most likely from the South Tianshan Orogen. The later erupted Group 1a basalts in the Keping area have been less contaminated with mainly the Tarim Precambrian rocks. Another group of the Tarim CFBs in the Northern Tarim Uplift (Group 2) appears to have undergone negligible crustal contamination but possesses evidence for variable source compositions. The modeling also indicates that the uncontaminated parental magmas of various Tarim LIP rocks (from the picrites and basalts to ultramafic{\textendash}mafic and syenitic intrusive rocks) exhibit a wide range of εNd(t) values (ca. -5{\textendash}5), reflecting source isotopic heterogeneity, which may be a consequence of plume{\textendash}lithosphere interaction during the generation of the Tarim LIP.},
	keywords = {Crustal contamination, Early Permian zircon, Keping basalts, Plume{\textendash}lithosphere interaction, Source isotopic heterogeneity, Tarim Large Igneous Province},
	issn = {0024-4937},
	doi = {https://doi.org/10.1016/j.lithos.2014.05.021},
	url = {http://www.sciencedirect.com/science/article/pii/S0024493714001856},
	author = {Yin-Qi Li and Zi-Long Li and Xing Yu and Charles H. Langmuir and Santosh, M. and Shu-Feng Yang and Han-Lin Chen and Zhong-Li Tang and Biao Song and Si-Yuan Zou}
}
@article {175096,
	title = {Geophysical and geochemical evidence for deep temperature variations beneath mid-ocean ridges, 344 80. DOI: 10.1126/ science.1249466},
	journal = {Science},
	volume = {16},
	year = {2014},
	author = {C. Dalton and Langmuir, C.H. and Gale, A.}
}
@article {170996,
	title = {The Global Systematics of Ocean Ridge Basalts and their Origin},
	journal = {Journal of Petrology},
	volume = {55},
	number = {6},
	year = {2014},
	pages = {1051-1082},
	author = {Allison Gale and Charles H. Langmuir and Colleen A. Dalton}
}
@article {175086,
	title = {Hafnium isotope evidence for slab melt contributions in the Central Mexican Volcanic Belt and implications for slab melting in hot and cold slab arcs},
	journal = {Chemical Geology},
	volume = {377},
	year = {2014},
	pages = {45-55},
	author = {Cai, Y. and Y. A LaGatta and Goldstein, S.L and Langmuir, C.H. and A. Gomez-Tuena and A.Martin-del-Pozzo and G. Carrasco-Nunez}
}
@article {631634,
	title = {  Older and Hotter, News and Views. },
	journal = {Nature Geoscience},
	volume = {6},
	year = {2013},
	pages = {332-333},
	author = {Langmuir, C.H.}
}
@article {GALE2013209,
	title = {Constraints on melting processes and plume-ridge interaction from comprehensive study of the FAMOUS and North Famous segments, Mid-Atlantic Ridge},
	journal = {Earth and Planetary Science Letters},
	volume = {365},
	year = {2013},
	pages = {209 - 220},
	abstract = {Detailed major element, trace element and isotopic study of the FAMOUS and North Famous segments within the geochemical gradient south of the Azores platform provides new constraints on controls on chemical variations at the segment scale and the origin of plume geochemical gradients. A comprehensive investigation of 110 samples along the entire length of the FAMOUS segment, coupled with a recent extensive melt inclusion study by Laubier et al. (2012), shows large trace element diversity within a single segment and substantial isotopic variability that largely correlates with trace element variations. Substantial variations are also present along the short (18km) North Famous segment despite the presence of an axial volcanic ridge. These results confirm multiple supply of magmas along the length of these segments, the lack of a centrally supplied magma chamber, and the ability of melting processes to deliver highly diverse melts over short distances and times. With the exception of one group of high Al2O3, low SiO2 magmas (HiAl{\textendash}LoSi) largely recovered in the original small FAMOUS area, the data can be simply explained by a two-component mixing model coupled with melting variations. The HiAl{\textendash}LoSi magmas reflect assimilation and mixing in the crust, an interpretation supported by the diverse melt inclusions in these lavas. Since the mantle heterogeneity reflects two-component mixing, the end members can be constrained. Surprisingly, source mixing between the Azores plume and depleted mantle cannot produce the observations. This is evident regionally from the fact that nearly all basalts have highly incompatible trace element ratios (e.g., Th/La, Nb/La) as high or higher than the most plume-influenced MORB near the Azores hotspot, despite being over 300km farther south and much less enriched isotopically. To account for the elevated highly incompatible trace element ratios, a metasomatic component formed by adding deep, low-degree melts of Azores plume material to a depleted mantle is required. The regional gradient south of the Azores then requires different processes along its length. Close to the Azores, plume material mixes with depleted mantle. The pure plume influence is spatially restricted, and enrichment farther to the south is caused by shallow mantle metasomatized by low-degree melts from deep plume flow. North Famous lavas are spatially closer to the Azores and yet are more depleted in trace elements and isotopes than FAMOUS lavas, suggesting delivery of the enriched component to individual segments is influenced by additional factors such as segment size and offset. The extent to which these processes operate in other regions of plume{\textendash}ridge interaction remains to be investigated.},
	keywords = {FAMOUS, mid-ocean ridge basalt, plume{\textendash}ridge interaction, trace element geochemistry},
	issn = {0012-821X},
	doi = {https://doi.org/10.1016/j.epsl.2013.01.022},
	url = {http://www.sciencedirect.com/science/article/pii/S0012821X13000393},
	author = {Allison Gale and Muriel Laubier and St{\'e}phane Escrig and Charles H. Langmuir}
}
@article {237941,
	title = {Mantle Geodynamics: Older and hotter},
	journal = {Nature Geoscience},
	volume = {6},
	year = {2013},
	pages = {332-333},
	url = {http://www.nature.com.ezp-prod1.hul.harvard.edu/ngeo/journal/v6/n5/full/ngeo1810.html},
	author = {Charles Langmuir}
}
@article {120046,
	title = {The mean composition of ocean ridge basalts},
	journal = {Geochem. Geophys. Geosyst.},
	year = {2013},
	author = {Gale, A. and C. A. Dalton and Langmuir, C.H. and Su, Y. and J.-G. E. Schilling}
}
@article {LI2012278,
	title = {Platinum-group elements and geochemical characteristics of the Permian continental flood basalts in the Tarim Basin, northwest China: Implications for the evolution of the Tarim Large Igneous Province},
	journal = {Chemical Geology},
	volume = {328},
	year = {2012},
	note = {Geochemical Perspectives on Mantle Dynamics and Plate Interactions in Asia: A Special Issue in Honor/Memory of Dr. Shen-su Sun},
	pages = {278 - 289},
	abstract = {Permian continental flood basalts (CFBs), as a main component for Tarim Large Igneous Province (TLIP), are widely distributed in the western and central parts of the Tarim Basin. Here we present a systematic study of platinum-group elements (PGEs) combined with conventional major, trace and Sr{\textendash}Nd isotopic geochemistry to characterize the Tarim CFBs from the Yingan section in the Keping area, west of the Tarim Basin. The basaltic units with a total thickness of ca. 400m in the section can be divided into two basaltic sequences: the lower Kupukuziman and the upper Kaipaizileike sequences. Both of the sequences display extremely low PGE concentrations, with Os, Ir, Ru, Rh, Pt and Pd contents of 0.014{\textendash}0.106, 0.007{\textendash}0.072, 0.035{\textendash}0.253, 0.011{\textendash}0.078, 0.043{\textendash}0.149 and 0.026{\textendash}0.124ppb, respectively. The Keping basalts exhibit a marked increase in Cu/Pd ratios (>105) albeit with a narrow range of lower Pd/Ir ratios (,
	keywords = {Continental flood basalts, Low-degree partial melting, Platinum-group elements, Sulfur saturation, Tarim Large Igneous Province},
	issn = {0009-2541},
	doi = {https://doi.org/10.1016/j.chemgeo.2012.03.007},
	url = {http://www.sciencedirect.com/science/article/pii/S0009254112001246},
	author = {Yin-Qi Li and Zi-Long Li and Ya-Li Sun and Santosh, M. and Charles H. Langmuir and Han-Lin Chen and Shu-Feng Yang and Zhong-Xing Chen and Xing Yu}
}
@article {120076,
	title = {Characterizing the effect of mantle source, subduction input and melting in the Fonualei Spreading Center, Lau Basin: Constraints on the origin of the boninitic signature of the back-arc lavas},
	journal = {Geochem. Geophys. Geosyst.},
	volume = {13},
	number = {Q10008},
	year = {2012},
	author = {Escrig, S. and A. B{\'e}zos and Langmuir, C.H. and Michael, P.J. and R. Arculus}
}
@article {120061,
	title = {Hf isotopic characteristics of the Tarim Permian large igneous province rocks of NW China: Implication for the magmatic source and evolution},
	journal = {Journal of Asian Earth Sciences},
	volume = {49},
	year = {2012},
	pages = {191-202},
	author = {Li, Z. and Li, Y. and H. Chen and Santosh, M. and Yang, Sh. and Xu, Y. and Langmuir, C.H. and Chen, Zh. and Yu, X. and Zou, S.}
}
@book {116421,
	title = {How to Build a Habitable Planet: The Story of Earth from the Big Bang to Humankind.},
	year = {2012},
	publisher = {Princeton University Press},
	organization = {Princeton University Press},
	address = {Princeton, NJ},
	author = {Charles Herbert Langmuir and Wallace S. Broecker}
}
@article {120071,
	title = {Links from mantle to microbe at the Lau Integrated Study Site: Insights from back-arc spreading center},
	journal = {Oceanography},
	volume = {25},
	number = {1},
	year = {2012},
	pages = {62-77},
	author = {Tivey, M.K. and Becker, E. and Beinart, C.R. and Girguis, P.R. and Langmuir, C.H. and Michael, P.J. and Reysenbach, A.L.}
}
@article {120091,
	title = {The magma plumbing system of Bezymianny Volcano: Insights from a 54 year time series of trace element whole-rock geochemistry and amphibole compositions},
	journal = {Journal of Volcanology and Geothermal Research},
	year = {2012},
	author = {Turner, S. J. and Izbekov, P. and Langmuir, C.H.}
}
@article {120051,
	title = {Melting and Crustal Processes at the FAMOUS Segment (Mid-Atlantic Ridge): New Insights from Olivine-Hosted Melt Inclusions from Multiple Samples},
	journal = {Journal of Petrology},
	volume = {53},
	number = {4},
	year = {2012},
	pages = {665-698},
	author = {Laubier, M.L. and Gale, A. and Langmuir, C.H.}
}
@article {120081,
	title = {The Processes of Melt Differentiation in Arc Volcanic Rocks: Insights from OIB-type Arc Magmas in the Central Mexican Volcanic Belt},
	journal = {Journal of Petrology},
	volume = {54},
	number = {4},
	year = {2012},
	pages = {665-701},
	author = {Straub, S. M. and G{\'o}mez-Tuena, A. and Zellmer, G. F. and Espinasa-Perena, R. and Stuart, F. M. and Cai, Y. and Langmuir, C.H. and Martin-Del Pozzo, A. L. and Mesko, G. T.}
}
@article {120126,
	title = {Assimilation of the plutonic roots of the Andean arc controls variations in U-series disequilibria at Volcan Llaima, Chile},
	journal = {Earth and Planetary Science Letters},
	volume = {303},
	number = {1-2},
	year = {2011},
	pages = {37-47},
	author = {Reubi, O. and Bourdon. B. and Dungan, M.A. and Koorneef, J.M. and Selles, D. and Langmuir, C.H. and Aciego, S.}
}
@article {120116,
	title = {Domains of depleted mantle: New evidence from hafnium and neodymium isotopes},
	journal = {Geochemistry Geophysics Geosystems},
	volume = {12},
	number = {Q10017},
	year = {2011},
	author = {Salters, V.J.M. and Mallick, S. and Hart, S.R. and Langmuir, C.E. and Stracke, A.}
}
@article {120106,
	title = {Enriched basalts at segment centers: The Lucky Strike (37 degrees 17 {\textquoteright} N) and Menez Gwen (37 degrees 50 {\textquoteright} N) segments of the Mid-Atlantic Ridge},
	journal = {Geochemistry Geophysics Geosystems},
	volume = {12},
	number = {Q06016},
	year = {2011},
	author = {Gale, A. and Escrig, S. and Gier, E.J. and Langmuir, C.H. and Goldstein, S.L}
}
@article {120111,
	title = {Insights into the mechanism of intermediate-depth earthquakes from source properties as imaged by back projection of multiple seismic phases},
	journal = {Journal of Geophysical Research-Solid Earth},
	volume = {116},
	number = {B06310},
	year = {2011},
	author = {Kiser, E. and Ishii, M. and Langmuir, C.H. and Shearer, P.M. and Hirose, H.}
}
@conference {Pedersen2010DiscoveryOA,
	title = {Discovery of a black smoker vent field and vent fauna at the Arctic Mid-Ocean Ridge},
	booktitle = {Nature communications},
	year = {2010},
	author = {Rolf Birger Pedersen and Hans Tore Rapp and Ingunn Hindenes Thorseth and Marvin D. Lilley and Fernando J. A. S. Barriga and Tamara Baumberger and Kristin Flesland and Rita Fonseca and Gretchen L. Fr{\"u}h-Green and Steffen Leth Jorgensen}
}
@article {120131,
	title = {Lithium isotopes in Guatemalan and Franciscan HP-LT rocks: Insights into the role of sediment-derived fluids during subduction},
	journal = {Geochimica et Cosmochimica Acta},
	volume = {74},
	number = {12},
	year = {2010},
	pages = {3621-3641},
	author = {Simons, K.K. and et al.}
}
@conference {Charles2009PetrologicalSO,
	title = {Petrological Systematics of Mid-Ocean Ridge Basalts : Constraints on Melt Generation Beneath Ocean Ridges},
	year = {2009},
	author = {M. Charles and Langmuir, C., and Emily M. Klein and Terry A. Plank}
}
@article {112136,
	title = {Chronology and geochemistry of Taxinan Permian basalts from the Tarim basin: evidence for Permian plume magmatism},
	journal = {Acta Petrologica Sinica},
	year = {2009},
	author = {Li Z.L. and Yang S.F. and Chen H.L. and Langmuir C.H. and Yu X. and Lin X.B. and Li Y.Q.}
}
@article {120136,
	title = {Distribution of recycled crust within the upper mantle: Insights from the oxygen isotope composition of MORB from the Australian-Antarctic Discordance},
	journal = {Geochem. Geophys. Geosyst.},
	volume = {10},
	number = {Q12004},
	year = {2009},
	author = {Cooper, K. M. and J. M. Eiler and K. W. W. Sims and Langmuir, C.H.}
}
@article {120161,
	title = {Feedback between deglaciation and volcanic emissions of CO2},
	journal = {Earth Planet. Sci. Lett.},
	volume = {286},
	year = {2009},
	pages = {479{\textendash}491},
	author = {Huybers, P. and Langmuir, C.}
}
@article {120156,
	title = {Mantle source variations beneath the Eastern Lau Spreading Center and the nature of subduction components in the Lau basin{\textendash}Tonga arc system},
	journal = {Geochem. Geophys. Geosyst.},
	volume = {10},
	number = {Q04014},
	year = {2009},
	author = {Escrig, S. and A. B{\'e}zos and Goldstein, S.L and Langmuir, C.H. and Michael, P.J.}
}
@article {120151,
	title = {Origins of chemical diversity of back-arc basin basalts: A segment-scale study of the Eastern Lau Spreading Center},
	journal = {J. Geophys. Res.},
	volume = {114},
	number = {B06212},
	year = {2009},
	author = {A. B{\'e}zos and Escrig, S. and Langmuir, C.H. and Michael, P.J. and P. D. Asimow}
}
@article {114141,
	title = {Central role of detachment faults in accretion of slow-spreading oceanic lithosphere},
	journal = {Nature},
	volume = {455},
	year = {2008},
	author = {Escartin, J. and Smith, D. K. and Cann, J. and Schouten, H. and Langmuir, C.H. and Escrig, S.}
}
@article {114146,
	title = {Evidence from high-Ni olivines for a hybridized peridotite/pyroxenite source for orogenic andesites from the central Mexican Volcanic Belt},
	journal = {Geochem. Geophys. Geosyst.},
	volume = {9},
	number = {3},
	year = {2008},
	author = {Straub, S. M. and LaGatta A.B. and Martin-Del Pozzo A.L. and Langmuir, C.H.}
}
@article {112141,
	title = {Lithium isotopes in global mid-ocean ridge basalts},
	journal = {Geochimica et Cosmochimica Acta},
	volume = {72},
	number = {6},
	year = {2008},
	pages = {1626-1637},
	author = {Tomascak, P. and Langmuir, C. and le Roux, P. and Shirey, S.}
}
@article {114151,
	title = {Origin of a {\textquoteleft}Southern Hemisphere{\textquoteright} geochemical signature in the Arctic upper mantle},
	journal = {Nature},
	volume = {453},
	year = {2008},
	author = {Goldstein, S.L and Soffer, G. and Langmuir, C.H. and Lehnert, K.A. and Graham, D.W. and Michael, P.J.}
}
@article {114156,
	title = {Adakitic dacites formed by intracrustal crystal fractionation of water-rich parent magmas at Nevado de Longavi volcano},
	journal = {J. Petrol.},
	volume = {48},
	year = {2007},
	pages = {2033-2061},
	author = {Rodriguez, C and Selles, D. and Dungan, M. and Langmuir, C. and Leeman, W.}
}
@article {114566,
	title = {Geochemical evidence for slab melting in the Trans-Mexican Volcanic Belt},
	journal = {J. Petrol.},
	volume = {48},
	number = {3},
	year = {2007},
	pages = {537-562},
	author = {G{\'o}mez-Tuena, A. and Langmuir, C. and Goldstein, S. \& Pinker, S. and Straub, S. and Ortega-Guti{\'e}rrez, F.}
}
@article {114576,
	title = {Mantle melting beneath mid-ocean ridges},
	journal = {Oceanography},
	volume = {20},
	number = {1},
	year = {2007},
	pages = {78-89},
	author = {Langmuir, C.H. and Forsyth, D.W.}
}
@article {114581,
	title = {Chemical systematics and hydrous melting of the mantle in Back-Arc Basins},
	journal = {AGU Geophysical Monograph Series},
	volume = {166},
	year = {2006},
	pages = {87-146},
	author = {Langmuir, C. and Bezos, A. and Escrig, S. and Parman, S.}
}
@article {114611,
	title = {Hydrothermal Exploration of the Fonualei Rift \&amp; Spreading Centre \&amp; NE Lau Spreading Centre},
	journal = {Geochem., Geophys., Geosyst.},
	volume = {7},
	number = {11},
	year = {2006},
	author = {German, C.R. and Baker E.T. and Connelly, D.P. and Lupton, J.E. and Resing, J. and Prien, R.D. and Walker, S.L. and Edmonds, H.N. and Langmuir, C.H.}
}
@article {631697,
	title = {Making waves: The voyage of HMS Challenger launched the science of oceanography},
	journal = {Nature},
	volume = {429},
	year = {2004},
	author = {Langmuir, C.}
}
@conference {Straub2004VolcanicGA,
	title = {Volcanic glasses at the Izu arc volcanic front : New perspectives on fluid and sediment melt recycling in subduction zones},
	year = {2004},
	author = {Susanne M. Straub and Schmidt, A.}
}
@article {Scaillet2004EarthSR,
	title = {Earth science: Role of fO2 on fluid saturation in oceanic basalt},
	journal = {Nature},
	volume = {430},
	year = {2004},
	pages = {-},
	author = {Bruno Scaillet and Michel Pichavant}
}
@conference {Baker2004HydrothermalVI,
	title = {Hydrothermal venting in magma deserts : The ultraslow-spreading Gakkel and Southwest Indian Ridges},
	year = {2004},
	author = {Edward T. Baker and Henrietta N. Edmonds and Henry J. B. Dick and Sharon L. Walker}
}
@conference {Carlut2004TimingOV,
	title = {Timing of volcanism along the northern East Pacific Rise based on paleointensity experiments on basaltic glasses},
	year = {2004},
	author = {Julie Carlut and Dennis V Kent and Katherine E. Donnelly and Charles H. Langmuir}
}
@article {Langmuir2004MakingW,
	title = {Making waves},
	journal = {Nature},
	volume = {429},
	year = {2004},
	pages = {131-131},
	author = {Charles H. Langmuir}
}
@article {COOPER2004297,
	title = {Oxygen isotope evidence for the origin of enriched mantle beneath the mid-Atlantic ridge},
	journal = {Earth and Planetary Science Letters},
	volume = {220},
	number = {3},
	year = {2004},
	pages = {297 - 316},
	abstract = {Geochemical variations in mid-ocean ridge basalts have been attributed to differing proportions of compositionally distinct mantle components in their sources, some of which may be recycled crust. Oxygen isotopes are strongly fractionated by near-surface interactions of rocks with the hydrosphere, and thus provide a tracer of near-surface materials that have been recycled into the mantle. We present here oxygen isotope analyses of basaltic glasses from the mid-Atlantic ridge south of and across the Azores platform. Variations in δ18O in these samples are subtle (range of 0.47{\textperthousand}) and may partly reflect shallow fractional crystallization; we present a method to correct for these effects. Relatively high fractionation-corrected δ18O in these samples is associated with geochemical indices of enrichment, including high La/Sm, Ce/Pb, and 87Sr/86Sr and low 143Nd/144Nd. Our results suggest two first-order conclusions about these enriched materials: (1) they are derived (directly or indirectly) from recycled upper oceanic crustal rocks and/or sediments; and (2) these materials are present in the north Atlantic MORB sources in abundances of less than 10\% (average 2{\textendash}5\%). Modeling of variations of δ18O with other geochemical variables further indicates that the enriched component is not derived from incorporation of sediment or bulk altered oceanic crust, from metasomatism of the mantle by hydrous or carbonate-rich fluids, or from partial melting of subducted sediment. Instead, the data appear to require a model in which the enriched component is depleted mantle that has been metasomatized by small-degree partial melts of subducted, dehydrated, altered oceanic crust. The age of this partial melting is broadly constrained to \~{}250 Ma. Reconstructed plate motions suggest that the enriched component in the north Atlantic mantle may have originated by subduction along the western margin of Pangea.},
	keywords = {mantle heterogeneity, Mid-Atlantic ridge, MORB, oxygen isotopes},
	issn = {0012-821X},
	doi = {https://doi.org/10.1016/S0012-821X(04)00058-5},
	url = {http://www.sciencedirect.com/science/article/pii/S0012821X04000585},
	author = {Kari M. Cooper and Eiler, John M. and Paul D. Asimow and Charles H. Langmuir}
}
@article {115151,
	title = {A hydrous melting and fractionation model for mid-ocean ridge basalts: Application to the Mid-Atlantic Ridge near the Azores},
	journal = {Geochem. Geophys. Geosyst.},
	volume = {5},
	number = {Q01E16},
	year = {2004},
	author = {Asimow P. D. and J. E. Dixon and Langmuir, C.H.}
}
@article {115161,
	title = {Origin of enriched ocean ridge basalts and implications for mantle dynamics},
	journal = {Earth and Planetary Science Letters},
	volume = {226},
	year = {2004},
	pages = {347-366},
	author = {Donnelly KE and Goldstein SL and Langmuir CH and et al.}
}
@article {631698,
	title = {Discovery of abundant hydrothermal venting on the ultra-slow spreading Gakkel Ridge, Arctic Ocean },
	journal = { Nature },
	volume = {421},
	year = {2003},
	pages = {252-256},
	author = {Edmonds, H and Michael, P. and Baker, E and Connelly, D and Snow, J and Langmuir, C. and Dick, H and M{\"u}he, R and German, C and Graham, D}
}
@article {doi:10.1029/2003GC000524,
	title = {Temporal control of subduction magmatism in the eastern Trans-Mexican Volcanic Belt: Mantle sources, slab contributions, and crustal contamination},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {4},
	number = {8},
	year = {2003},
	abstract = {The magmatic record of the easternmost part of the Trans-Mexican Volcanic Belt elucidates how temporal changes in subduction parameters influence convergent margin volcanism. In the Palma Sola massif, three phases of magmatic rocks with distinct chemical characteristics were emplaced in a relatively short time span (\~{}17 Ma): Miocene calc-alkaline plutons, latest Miocene-Pleistocene alkaline plateau basalts, and Quaternary calc-alkaline cinder cones. Plutons have arc-like trace element patterns (Ba/Nb = 16{\textendash}101), and their Sr, Nd, and Pb isotopic compositions become more {\textquotedblleft}depleted{\textquotedblright} with increasing SiO2 contents. Their Pb isotopes are bracketed by the subducted sediments and Pacific mid-ocean ridge basalts (MORB), requiring the participation of an unradiogenic component that mixes with a sediment contribution. High Sr/Y and Gd/Yb ratios in the least radiogenic pluton might indicate a melt coming from the subducted MORB. Trace element patterns of the plateau basalts show moderate or negligible subduction contributions (Ba/Nb = 6{\textendash}31). Rocks without subduction signatures are similar to ocean island basalts, indicating melting of an enriched mantle wedge. The plateau basalts form an array in 206Pb/204Pb-207Pb/204Pb space that trends toward the composition of the subducted sediment. The sediment component is also indicated by the inverse correlations between Pb isotopes and subduction signals. This component has high Th/Nd coupled with low 143Nd/144Nd, but lower Pb/Nd and Sr/Nd ratios than the bulk sediment. These suggest melting of a sediment that has lost fluid mobile elements prior to melting. The Quaternary cinder cones have moderate subduction signals (Ba/Nb = 16{\textendash}41), and their isotopic compositions correlate with differentiation indices. Contamination with the local Paleozoic basement can explain the petrogenesis of the youngest rock suite. The geochemical differences among the suites indicate temporal modifications in the chemical characteristics of the slab input. These variations can be associated with modifications in the Pacific subduction regime. We suggest the Miocene magmatic phase was formed by an essentially flat subduction angle that favored melting of the subducted oceanic crust. Slab rollback in the Pliocene allowed melting of deeper portions of the wedge by the injection of dehydrated sediment melts. In the Quaternary, an even steeper subduction angle provided negligible slab contributions to the Palma Sola region, and upper crustal contamination largely controls the petrogenesis.},
	keywords = {mantle wedge, sediment melt, slab melt, subduction zone magmatism},
	doi = {10.1029/2003GC000524},
	url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2003GC000524},
	author = {G{\'o}mez-Tuena, Arturo and LaGatta, Alexandra B. and Charles H. Langmuir and Steven L. Goldstein and Ortega-Guti{\'e}rrez, Fernando and Carrasco-N{\'u}{\~n}ez, Gerardo}
}
@conference {Katz2003ANP,
	title = {A New Parameterization of Hydrous Mantle Melting},
	year = {2003},
	author = {Richard F. Katz and M. Spiegelman and Charles H. Langmuir}
}
@article {Asimow2003TheIO,
	title = {The importance of water to oceanic mantle melting regimes},
	journal = {Nature},
	volume = {421},
	year = {2003},
	pages = {815-820},
	author = {Paul D Asimow and Charles H. Langmuir}
}
@conference {Su2003PetroPlotA,
	title = {PetroPlot : A plotting and data management tool set for Microsoft Excel},
	year = {2003},
	author = {Yongjun Su and Charles H. Langmuir}
}
@article {Michael2003MagmaticAA,
	title = {Magmatic and amagmatic seafloor generation at the ultraslow-spreading Gakkel ridge, Arctic Ocean},
	journal = {Nature},
	volume = {423},
	year = {2003},
	pages = {956-961},
	author = {Peter J. Michael and Charles H. Langmuir and Henry J. B. Dick and Jonathan E. Snow and Steven L. Goldstein and David W. Graham and Konrad W. Lehnert and Gregory J. Kurras and Wilfried Jokat and Richard M{\"u}he and Henrietta N. Edmonds}
}
@article {631699,
	title = {Recycled dehydrated lithosphere observed in plume-influenced mid-ocean-ridge basalt },
	journal = {Nature},
	volume = {420},
	year = {2002},
	pages = {385-389},
	author = {Dixon, J and Leist, L and Langmuir, C. and Schilling, J.-G}
}
@article {doi:10.1029/2001GC000205,
	title = {Consequences of diffusive reequilibration for the interpretation of melt inclusions},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {3},
	number = {4},
	year = {2002},
	pages = {1-26},
	abstract = {Trace element abundances in melt inclusions are commonly used to interpret melting and melt extraction processes. These interpretations, however, often assume that the chemical compositions of melt inclusions are identical to the liquid from which the host crystal grew, even though driving forces for postentrapment diffusion and modification are demonstrable. This paper begins to quantify the effects of diffusion on melt inclusions using a numerical model. The model calculates the compositional evolution of a spherical inclusion which initially is in equilibrium with a crystal host out to some distance rjump and out of equilibrium beyond. In particular we consider the end-member scenario, whereby the trapped melt is initially out of equlibrium with the neighboring crystal as this sets the minimum time for reequilibration. A package of numerical codes is provided that allows the user to explore other initial conditions. The model calculates the change in inclusion composition and also the structure of diffusion halos that grow around the inclusion as it reequilibrates with the surrounding crystal. The detection of these profiles in naturally occurring inclusions may allow the time since entrapment and the initial inclusion concentration to be estimated. The extent of reequilibration is most strongly influenced by the partition coefficient, diffusivity, and the inclusion radius. Fast-diffusing elements with high mineral/melt partition coefficients are modified rapidly, particularly in small inclusions. Because minerals have very different Dmineral/melt for the various elements, the effects of diffusive reequilibration differ substantially from one mineral to another. For example, the higher partition coefficients of the heavy rare earth elements (HREE) in olivine make HREE concentrations easier to modify than light rare earth elements (LREE) concentrations. In contrast, Sr, Eu, and Ba in plagioclase hosted inclusions equilibrate more rapidly than the other trace elements. Examination of published trace element concentrations of olivine hosted inclusions show little evidence for reequilibration, at least for the light REE and other highly incompatible elements. It is difficult, however, to provide firm constraints due to the uncertainties in olivine diffusivities and the initial condition. In contrast, trace element diffusivities in plagioclase have been determined experimentally [Cherniak, 2001], and the trace element concentrations of published plagioclase hosted inclusions show evidence for extensive diffusive exchange with the host in a manner consistent with model predictions. Postentrapment modification therefore is likely an important factor in the interpretation of some melt inclusion data.},
	keywords = {Diffusion, Melt inclusions, MORB, numerical modeling, rare earth elements, Trace Elements},
	doi = {10.1029/2001GC000205},
	url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2001GC000205},
	author = {Cottrell, E. and M. Spiegelman and Langmuir, C.H.}
}
@article {Dixon2002RecycledDL,
	title = {Recycled dehydrated lithosphere observed in plume-influenced mid-ocean-ridge basalt},
	journal = {Nature},
	volume = {420},
	year = {2002},
	pages = {385-389},
	author = {Jacqueline Eaby Dixon and Loretta Leist and Charles H. Langmuir and Jean-Guy Schilling}
}
@conference {Kempton2002SrNdPbHfIR,
	title = {Sr-Nd-Pb-Hf isotope results from ODP Leg 187 : Evidence for mantle dynamics of the Australian-Antarctic Discordance and origin of the Indian MORB source},
	year = {2002},
	author = {Pamela D. Kempton and Julian A. Pearce and T L Barry and Godfrey Fitton and David M. Christie}
}
@article {Saal2002VapourUI,
	title = {Vapour undersaturation in primitive mid-ocean-ridge basalt and the volatile content of Earth{\textquoteright}s upper mantle},
	journal = {Nature},
	volume = {419},
	year = {2002},
	pages = {451-455},
	author = {Alberto E. Saal and Erik H Hauri and Charles H. Langmuir and Michael R. Perfit}
}
@article {doi:10.1029/2000GC000165,
	title = {Hydrothermal plumes along segments of contrasting magmatic influence, 15{\textdegree}20'{\textendash}18{\textdegree}30'N, East Pacific Rise: Influence of axial faulting},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {2},
	number = {9},
	year = {2001},
	abstract = {Vertical profiles of light backscattering and temperature recorded on 133 rock cores and dredge hauls between the Orozco and Rivera transform faults on the East Pacific Rise (EPR) (15{\textdegree}20'{\textendash}18{\textdegree}30'N) provide an opportunity to compare the hydrothermal environment of three adjacent but distinctly different segments that span the maximum range of axial cross section at a relatively constant spreading rate. Contrary to predictions based on data from other Pacific ridges, hydrothermal plumes over the inflated 16{\textdegree}N segment were less extensive and weaker than along the narrower, rifted 17{\textdegree}N segment. Remarkably, the 17{\textdegree}N segment has a plume incidence equal to the mean of superfast spreading segments from the southern EPR. The data suggest that the local permeability environment in this region controls the expression of hydrothermal activity in the water column. The 16{\textdegree}N segment, which has little or no indication of faulting, may have its hydrothermal activity presently suppressed by widespread volcanic flows that act as an impermeable cap over much of the segment. Activity on the 17{\textdegree}N segment may be tectonically enhanced, with hydrothermal fluids circulating through deep faults to a cracking front. Within each segment, intense hydrothermal plumes characteristic of focused discharge seem associated with clearly rifted areas, while weaker water column signals characteristic of diffuse discharge are associated with unrifted portions of the ridge axis that appear dominated by magmatism. Previous studies at intermediate- to-superfast spreading ridges have emphasized a positive correlation between local magmatic budget and hydrothermal activity. Our data suggest, however, that even at fast rates local tectonics can control the extent and nature of hydrothermal activity, as documented for several sites on the slow-spreading Mid-Atlantic Ridge. Despite the segment-scale incongruity between hydrothermal activity and magmatic budget, the fraction of total ridge length between 15{\textdegree}20' and 18{\textdegree}30'N overlain by plumes (0.39) follows the existing global correlation between plume incidence and spreading rate.},
	keywords = {East Pacific Rise, hydrothermal plumes, magmatic budget, tectonics},
	doi = {10.1029/2000GC000165},
	url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2000GC000165},
	author = {Edward T. Baker and Cormier, Marie-Helene and Charles H. Langmuir and Zavala, Karina}
}
@article {631638,
	title = { Cadmium, indium, tin, terrarium, and sulfur in oceanic basalts: Implications for chaocophile element fractionation in the Earth. },
	journal = {J. Geophys. Res.},
	volume = {105},
	year = {2000},
	pages = {18927-18948.},
	author = {Yi, W. and Halliday, A. and D. Lee and Alt, J. and Rehkamper, M. and Garcia, M. and Langmuir, C. and Su, Y.}
}
@article {doi:10.1029/1999GC000010,
	title = {Distinguishing melt and fluid subduction components in Umnak Volcanics, Aleutian Arc},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {1},
	number = {6},
	year = {2000},
	abstract = {Plate processing at convergent margins plays a central role in the distribution of elements among major earth reservoirs. The mechanisms by which this distribution occurs, however, have remained poorly constrained. This paper provides new constraints through a detailed isotope and trace element study of volcanic rocks from Umnak Island, Central Aleutian Arc. The data require the addition of three distinct subduction components to the subarc mantle, which are characterized and quantified: (1) a hydrous fluid from subducted oceanic crust, with mid-ocean ridge basalt (MORB)-like isotopic compositions but high Pb/Nd; (2) a hydrous fluid from subducted sediment, with sediment-like isotopic compositions and an enrichment in fluid-mobile elements; (3) a sediment partial melt, with sediment-like isotopic compositions and high Th/Nd and Th/Nb compared to both regional and global sediments. The sediment melt is depleted in fluid-mobile elements, indicating loss of fluid prior to melting. The high Th/Nb of the sediment melt indicates presence of a Ti-rich residual phase such as rutile during partial melting. The observation that sediment fluid and sediment melt can be distinguished in different volcanic rocks suggests that they arrive separately at the sites of arc magma formation. This indicates release of multiple discrete fluid and melt phases from sediment to the overlying mantle wedge, which can be viewed as a natural consequence of progressive metamorphism of the subducting slab.},
	keywords = {island arcs, mantle wedge, rutile, sediment fluid, sediment melt, subduction components},
	doi = {10.1029/1999GC000010},
	url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/1999GC000010},
	author = {Class, Cornelia and Miller, Daniel M. and Steven L. Goldstein and Charles H. Langmuir}
}
@article {doi:10.1029/1999GC000033,
	title = {Identification and implications of off-axis lava flows around the East Pacific Rise},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {1},
	number = {6},
	year = {2000},
	abstract = {Off-axis eruptions at ocean ridges provide critical information with respect to underlying crustal plumbing and mantle melting systems. A detailed study of basaltic glass samples around the East Pacific Rise from 12{\textdegree}00' to 12{\textdegree}30'N provides geological evidence for the existence of off-axis eruptions with a distinctive chemical composition. This composition has not been found along the axis of the EPR from 8{\textdegree} to 14{\textdegree}N except at a ridge-transform intersection but has been recovered in numerous locations that were farther than 1 km off axis. These off-axis normal mid-ocean ridge basalts, or OA-NMORB, are distinguished by low Na2O, Sr, and Al2O3 and are unusually depleted in incompatible elements. Moderately enriched off-axis transitional mid-ocean ridge basalts (OA-TMORB) with the same compositional tendencies can also be identified. Comparison of EPR axis lavas and the OA type suggests that they come from the same range of (unmelted) mantle source compositions but that the source of the OA magmas was depleted in incompatible trace elements by removal of a small- degree partial melt. This would be consistent with the OA type as an EPR pooled melt that is missing the low-degree melt fraction from deep in the melting regime, which provides a reasonable physical model for their formation. In this case, off-axis magmas do not represent the same range of chemical variation as magmas delivered to the axial magma system. The OA-NMORB are similar to depleted lavas from near-EPR seamounts. Other seamount lavas with depleted trace elements have TMORB-like major elements, and may be classified as OA-TMORB. The similarity between seamount lavas and the lavas erupted off axis close to the EPR suggests that the two are manifestations of the same phenomenon. We suggest that seamount-type volcanism effectively starts within 1{\textendash}2 km of the axis. This is within the range where lavas derived from the axial plumbing system may also erupt. Therefore there is a narrow zone where young lava flows from the axial plumbing system and from the off-axis systems may overlap. Lavas erupted off axis may ultimately cover 20\% of the seafloor around the EPR, which is substantially more than previous estimates that were based primarily on morphological studies.},
	keywords = {East Pacific Rise, mantle melting, melt focusing, MORB, off axis, seamount},
	doi = {10.1029/1999GC000033},
	url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/1999GC000033},
	author = {Jennifer R. Reynolds and Charles H. Langmuir}
}
@article {doi:10.1029/1999GC000026,
	title = {A global geochemical database structure for rocks},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {1},
	number = {5},
	year = {2000},
	abstract = {This technical brief describes a geochemical and petrological database structure based on the relational model that has broad applicability to chemical analyses of geological materials. Notable features of the database structure are its comprehensiveness and flexibility. The structure consists of 34 interrelated tables, which can accommodate any type of analytical values for all different materials of rock samples (volcanic glasses, minerals, inclusions, etc.) and for samples from any tectonic setting. A broad spectrum of supplementary information (metadata) is included that describes the quality of the analytical data and sample characteristics, such as petrography, geographical location, and sampling process, and that can be used to evaluate, filter, and sort the chemical data. All data in the database are linked to their original reference. The database structure can be implemented in any relational database management system (RDBMS). It is currently applied in two different rock database projects (RidgePetDB and GEOROC).},
	keywords = {data management, database, geochemistry, petrology},
	doi = {10.1029/1999GC000026},
	url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/1999GC000026},
	author = {Lehnert, K. and Su, Y. and Langmuir, C.H. and Sarbas, B. and Nohl, U.}
}
@article {doi:10.1029/1999GC000024,
	title = {Petrology and Sr, Nd, and Pb isotope geochemistry of mid-ocean ridge basalt glasses from the 11{\textdegree}45'N to 15{\textdegree}00'N segment of the East Pacific Rise},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {1},
	number = {11},
	year = {2000},
	abstract = {Basaltic glasses from the geophysically well-studied section of the East Pacific Rise (EPR) between 11{\textdegree}45'N to 15{\textdegree}00'N range from normal mid-ocean ridge basalts (MORB) to transitional MORB and their major element variations correlate with isotopic and trace element indices of enrichment. To first order, basalts enriched in Na8.0, incompatible elements, 87Sr/86Sr, and 206Pb/204Pb but low in Fe8.0 and 143Nd/144Nd are more prevalent along the shallow portions of the ridge axis. In detail, the samples can be divided into two chemical and geographical Groups: the southern bathymetric dome, extending from the 11{\textdegree}45'N overlapping spreading center to \~{}14{\textdegree}10'N, and the northern Group, extending from \~{}14{\textdegree}10'N to the Orozco transform. The boundary between these two Groups is apparent in a change in isotopic composition. Results indicate that there are three mantle source components that produce the compositional variability observed among samples from the 11{\textdegree}45'N to 15{\textdegree}00'N segment of the EPR: a depleted mantle component, a seamount-type enriched mantle component, and an Indian MORB-like mantle component. South of \~{}14{\textdegree}10'N, the geochemical variability is dominated by binary mixing between a depleted mantle component and an enriched component similar to near-ridge seamounts. North of \~{}14{\textdegree}10'N, the low 206Pb/204Pb, high 207Pb/204Pb Indian MORB-like component exerts a major influence on the geochemical variability of the axial lavas. Regional averages of major element composition (e.g., Na8.0 and Fe8.0) show relatively limited variability consistent with the restricted range in depth for this region and plot within the Pacific field of the previously defined global trends. Major element variations among individual samples, however, parallel the global array, and their correlation with indices of mantle enrichment supports the idea that the {\textquotedblleft}Pacific-type local trend{\textquotedblright} results from small-scale heterogeneities in the mantle beneath the EPR. Our results also indicate that tectonic segmentation and magmatic boundaries are probably not causally related in this study area and that the sizes of the present magma chambers are not a dominant factor in determining the compositional variability of erupted lavas.},
	keywords = {basalt, East Pacific Rise, Isotopes, mantle heterogeneity, mid-ocean ridge, Trace Elements},
	doi = {10.1029/1999GC000024},
	url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/1999GC000024},
	author = {Castillo, P. R. and Klein, E. and J. Bender and Langmuir, C. and Shirey, S. and Batiza, R. and White, W.}
}
@article {doi:10.1029/2000GC000047,
	title = {Evidence from 10Be and U series disequilibria on the possible contamination of mid-ocean ridge basalt glasses by sedimentary material},
	journal = {Geochemistry, Geophysics, Geosystems},
	volume = {1},
	number = {8},
	year = {2000},
	abstract = {It has often been suggested that U series disequilibria measured in mid-ocean ridge basalts (MORB) can be perturbed by contamination with sedimentary or hydrothermal material found near the ridge axis where the basalts are erupted. Here we provide an independent way of estimating the maximum degree of contamination by sediment using constraints from 10Be. Since 10Be is mostly a cosmogenic nuclide and has a half life of 1.5 {\texttimes} 106 years, any 10Be found in a MORB glass must result from contamination by sedimentary material where cosmogenic 10Be is enriched. Four MORB samples with a wide range in Th concentrations (87{\textendash}550 ppb) were measured for U decay series and 10Be. No 10Be above the detection limit (6 {\texttimes} 104 to 1 {\texttimes} 105 atoms) was measured in the glasses except for one sample that was not picked. Considering that the sedimentary contaminant contains 109 to 1010 atoms/g, the maximum fraction of contaminant in the picked glasses is 10-4 to 10-5. Mass balance calculations between a surficial contaminant and a hypothetical pristine glass with (231Pa/235U) = 1 and (10Be/9Be) = 0 show that only for the unpicked sample, nearly all the measured excess 231Pa can be accounted for by contamination. For the other samples, ,
	keywords = {10Be, basalt, contamination, mid-ocean ridge, U series},
	doi = {10.1029/2000GC000047},
	url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2000GC000047},
	author = {B. Bourdon and Goldstein, S. J. and Bourl{\`e}s, D. and Murrell, M. T. and Langmuir, C.H.}
}
@conference {Korenaga2000MajorEH,
	title = {Major element heterogeneity in the mantle source of the North Atlantic igneous province},
	year = {2000},
	author = {Jun Korenaga and Peter b. Kelemen}
}
@article {DOSSO1999269,
	title = {The age and distribution of mantle heterogeneity along the Mid-Atlantic Ridge (31{\textendash}41{\textdegree}N)},
	journal = {Earth and Planetary Science Letters},
	volume = {170},
	number = {3},
	year = {1999},
	pages = {269 - 286},
	abstract = {New trace element and isotopic data for basalts from the mid-Atlantic ridge between 31 and 41{\textdegree}N allow a better description of the geochemical gradient south of the Azores triple junction, and the systematics of mantle source heterogeneity. There is a long wavelength enrichment in incompatible trace elements and isotopes associated with the Azores hot spot that extends from the Kurchatov fracture zone near 41{\textdegree}N to the Hayes fracture zone near 33{\textdegree}N. Superimposed on this gradient are local spikes of enrichment, the most prominent being the anomaly near the Oceanographer Fracture Zone (NOFZ). The Oceanographer anomaly spike is reflected modestly in the morphology of the ridge axis, but is not obviously related to a plume. The isotopic data alone are consistent with involvement of subcontinental material, but the samples do not contain the negative Nb{\textendash}Ta anomalies which are usually associated with the presence of continental material in the mantle source. Away from the prominent enrichment spikes associated with the Azores and Oceanographer fracture zone, there are systematic relationships in this region between parent/daughter element ratios and isotope ratios. The Pb, Sr and Nd isotope systems all give apparent ages in the range 100 Ma to 300 Ma, with the age increasing with likely parent/daughter fractionation during melting (U/Pb < Rb/Sr < Sm/Nd age). Monte Carlo simulations of an enrichment event in a depleted heterogeneous mantle at 250 Ma produce results that correspond well with the observations for all three isotopic systems. Since this age also corresponds to the pre-opening of the North Atlantic, it raises the possibility that some of the heterogeneity in this region is associated with shallow level mantle heterogeneity resulting from the rifting of Gondwanaland rather than from interaction with mantle plumes. The data may also reflect a mean mixing time for the heterogeneities in the upper mantle source. Sr isotope systematics reveal correlations in a 87Sr/86Sr versus 87Rb/86Sr plot, which are geographically controlled. Data points from 10{\textendash}24{\textdegree}N samples and data points from 31{\textendash}38{\textdegree}N samples (excluding NOFZ samples) plot on two offset trends of similar slope. Irrespective of the origin of the isotopic variations, these data require end member depleted mantle with distinct isotopic characteristics. Depleted sources with low 87Rb/86Sr (0.005{\textendash}0.04) and low (La/Sm)N (,
	keywords = {age, fractionation, isotope ratios, Mid-Atlantic ridge, mid-ocean ridge basalts},
	issn = {0012-821X},
	doi = {https://doi.org/10.1016/S0012-821X(99)00109-0},
	url = {http://www.sciencedirect.com/science/article/pii/S0012821X99001090},
	author = {Laure Dosso and Henri Bougault and Charles Langmuir and Claire Bollinger and Olga Bonnier and Jo{\"e}l Etoubleau}
}
@article {HUMLERA19997,
	title = {Depth versus age: new perspectives from the chemical compositions of ancient crust},
	journal = {Earth and Planetary Science Letters},
	volume = {173},
	number = {1},
	year = {1999},
	pages = {7 - 23},
	abstract = {Petrological data provide a new approach to an evaluation of the depth{\textendash}age problem for ancient seafloor. The correlations among basalt chemical composition, axial depth and mantle temperature at current ocean ridges allow the determination of initial depth and mantle temperature for any portion of ancient seafloor that was created at a spreading center, provided the chemical composition of the ancient crust is determined. It is then possible to calculate a petrologically constrained depth at any age, which can be compared to observed depths and depths from the classical half space models. We evaluate data from DSDP and ODP drill holes on crust older than 80 Ma, considering chemical composition, back-tracked depth and crustal thickness. The data are complex, and interpretation of their chemical composition requires consideration of alteration, absence of glass compositions, data quality, and the influence of off-axis volcanism and near-ridge hot spots. To check and expand the data set, we develop and use trace element proxies for major element compositions, since many trace element ratios are less influenced by alteration and by variable proportions of phenocrysts. The twenty drill holes for which reliable data can be obtained are well distributed around the globe, and include multiple sites on old crust in the Atlantic, Pacific and Indian ocean basins. Comparison of the chemical and crustal distributions between ancient and current N-MORB show that the oceanic crust older than 80 Ma has significantly lower Na8.0,Zr/Y, Sm/YbN, and higher CaO/Al2O3,Fe8.0 and crustal thickness. Quantitative modeling of these results suggests that the mantle was hotter in this time period by about 50{\textdegree}C, that the cruss was several hundred meters shallower and 1{\textendash}2 km thicker. These observations show that half to two thirds of the observed flattening relative to a half space model is due to the change in mantle temperature and crustal composition. Thus, only a few hundred meters of flattening by plate reheating by hot spots or by other mechanisms is required. These results are consistent with the existence of abundant oceanic plateaus even at fast-spreading rates in the Mesozoic, and with the apparent thickening of ocean crust with time.},
	keywords = {Deep Sea Drilling Project, lithosphere, Ocean Drilling Program, oceanic crust, thermal history, vertical movements},
	issn = {0012-821X},
	doi = {https://doi.org/10.1016/S0012-821X(99)00218-6},
	url = {http://www.sciencedirect.com/science/article/pii/S0012821X99002186},
	author = {Eric Humlera and Charles Langmuirb and Vai{\'e}rie Dauxc}
}
@article {PLANK1998325,
	title = {The chemical composition of subducting sediment and its consequences for the crust and mantle},
	journal = {Chemical Geology},
	volume = {145},
	number = {3},
	year = {1998},
	pages = {325 - 394},
	abstract = {Subducted sediments play an important role in arc magmatism and crust{\textendash}mantle recycling. Models of continental growth, continental composition, convergent margin magmatism and mantle heterogeneity all require a better understanding of the mass and chemical fluxes associated with subducting sediments. We have evaluated subducting sediments on a global basis in order to better define their chemical systematics and to determine both regional and global average compositions. We then use these compositions to assess the importance of sediments to arc volcanism and crust{\textendash}mantle recycling, and to re-evaluate the chemical composition of the continental crust. The large variations in the chemical composition of marine sediments are for the most part linked to the main lithological constituents. The alkali elements (K, Rb and Cs) and high field strength elements (Ti, Nb, Hf, Zr) are closely linked to the detrital phase in marine sediments; Th is largely detrital but may be enriched in the hydrogenous Fe{\textendash}Mn component of sediments; REE patterns are largely continental, but abundances are closely linked to fish debris phosphate; U is mostly detrital, but also dependent on the supply and burial rate of organic matter; Ba is linked to both biogenic barite and hydrothermal components; Sr is linked to carbonate phases. Thus, the important geochemical tracers follow the lithology of the sediments. Sediment lithologies are controlled in turn by a small number of factors: proximity of detrital sources (volcanic and continental); biological productivity and preservation of carbonate and opal; and sedimentation rate. Because of the link with lithology and the wealth of lithological data routinely collected for ODP and DSDP drill cores, bulk geochemical averages can be calculated to better than 30\% for most elements from fewer than ten chemical analyses for a typical drill core (100{\textendash}1000 m). Combining the geochemical systematics with convergence rate and other parameters permits calculation of regional compositional fluxes for subducting sediment. These regional fluxes can be compared to the compositions of arc volcanics to asses the importance of sediment subduction to arc volcanism. For the 70\% of the trenches worldwide where estimates can be made, the regional fluxes also provide the basis for a global subducting sediment (GLOSS) composition and flux. GLOSS is dominated by terrigenous material (76 wt\% terrigenous, 7 wt\% calcium carbonate, 10 wt\% opal, 7 wt\% mineral-bound H2O+), and therefore similar to upper continental crust (UCC) in composition. Exceptions include enrichment in Ba, Mn and the middle and heavy REE, and depletions in detrital elements diluted by biogenic material (alkalis, Th, Zr, Hf). Sr and Pb are identical in GLOSS and UCC as a result of a balance between dilution and enrichment by marine phases. GLOSS and the systematics of marine sediments provide an independent approach to the composition of the upper continental crust for detrital elements. Significant discrepancies of up to a factor of two exist between the marine sediment data and current upper crustal estimates for Cs, Nb, Ta and Ti. Suggested revisions to UCC include Cs (7.3 ppm), Nb (13.7 ppm), Ta (0.96 ppm) and TiO2 (0.76 wt\%). These revisions affect recent bulk continental crust estimates for La/Nb and U/Nb, and lead to an even greater contrast between the continents and mantle for these important trace element ratios. GLOSS and the regional sediment data also provide new insights into the mantle sources of oceanic basalts. The classical geochemical distinction between {\textquoteleft}pelagic{\textquoteright} and {\textquoteleft}terrigenous{\textquoteright} sediment sources is not valid and needs to be replaced by a more comprehensive understanding of the compositional variations in complete sedimentary columns. In addition, isotopic arguments based on surface sediments alone can lead to erroneous conclusions. Specifically, the Nd/Hf ratio of GLOSS relaxes considerably the severe constraints on the amount of sediment recycling into the mantle based on earlier estimates from surface sediment compositions.},
	issn = {0009-2541},
	doi = {https://doi.org/10.1016/S0009-2541(97)00150-2},
	url = {http://www.sciencedirect.com/science/article/pii/S0009254197001502},
	author = {Terry Plank and Charles H. Langmuir}
}
@article {STAUDIGEL1998153,
	title = {Geochemical Earth Reference Model (GERM): description of the initiative},
	journal = {Chemical Geology},
	volume = {145},
	number = {3},
	year = {1998},
	pages = {153 - 159},
	abstract = {The Geochemical Earth Reference Model (GERM) initiative is a grass-root effort with the goals of establishing a community consensus on a chemical characterization of the Earth, its major reservoirs, and the fluxes between them. The GERM initiative will provide a review of available scientific constraints for: (1) the composition of all major chemical reservoirs of the present-day Earth, from core to atmosphere; (2) present-day fluxes between reservoirs; (3) the Earth{\textquoteright}s chemical and isotopic evolution since accretion; and (4) the chemical and isotopic evolution of seawater as a record of global tectonics and climate. Even though most of the constraints for the GERM will be drawn from chemical data sets, some data will have to come from other disciplines, such as geophysics, nuclear physics, and cosmochemistry. GERM also includes a diverse chemical and physical data base and computer codes that are useful for our understanding of how the Earth works as a dynamic chemical and physical system. The GERM initiative is developed in an open community discussion on the World Wide Web (http://www-ep.es.llnl.gov/germ/germ-home.html) that is moderated by editors with responsibilities for different reservoirs, fluxes, data bases, and other scientific or technical aspects. These editors have agreed to lay out an initial, strawman GERM for their respective sections and to moderate community discussions leading to a first, preliminary consensus. The development of the GERM began with an initial workshop in Lyon, France in March, 1996. Since then, the GERM has continued to be developed on the Internet, punctuated by workshops and special sessions at professional meetings. A second GERM workshop will be held in La Jolla, CA USA on March 10{\textendash}13, 1998.},
	keywords = {Differentiation of the Earth, Fluxes, Geochemical cycles, Geochemical reservoirs, Residence time, Transfer dynamics},
	issn = {0009-2541},
	doi = {https://doi.org/10.1016/S0009-2541(97)00141-1},
	url = {http://www.sciencedirect.com/science/article/pii/S0009254197001411},
	author = {Hubert Staudigel and Francis Albar{\`e}de and Janne Blichert-Toft and John Edmond and Bill McDonough and Stein B Jacobsen and Ralph Keeling and Charles H. Langmuir and Roger L Nielsen and Terry Plank and Roberta Rudnick and Henry F Shaw and Steve Shirey and Jan Veizer and White, William}
}
@article {doi:10.1029/97JB00391,
	title = {Petrological systematics of the Mid-Atlantic Ridge south of Kane: Implications for ocean crust formation},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {102},
	number = {B7},
	year = {1997},
	pages = {14915-14946},
	abstract = {Models of ridge segmentation, mantle flow and melt focusing predict how the chemical compositions of mantle melts should vary along a mid-ocean ridge axis. The compositions of basaltic lavas can be compared to these predictions to test the models. Such tests have been carried out using basalts from the neovolcanic zone south of the Kane fracture zone (the MARK area), where there are both a large transform and nontransform offsets. Before evaluating mantle models, the effects of differentiation must be accounted for. Fractional crystallization at low pressures (constrained by new melting experiments on these samples) does not account for the data. High pressure or in situ crystallization better account for the differentiation trends; however, these two processes imply different relationships between magmatic differentiation and position within a segment. Irrespective of the differentiation model, significant differences exist among parental magmas. Magmas near the transform have much lower levels of highly incompatible trace elements but higher levels of moderately incompatible trace elements, suggesting both lower extents of melting and a more depleted source. These two characteristics may be natural consequences of the truncation of a melting regime by a large-offset transform: depleted mantle from across the transform may contribute to the melting regime, while the cooler thermal environment produces less melt. Quantitative modeling of these geochemical characteristics produces thin crust near the transform, consistent with seismic and gravity studies. In contrast, thin crust adjacent to nontransform offsets is associated with no reduction in extent of mantle melting. These results, along with data from other regions, suggest that nontransform offsets overlie a continuous melting regime, and melt focusing creates the variations in crustal thickness. Focused flow may also lead to incompatible element enrichment at segment centers, and relative depletion at segment margins. Only offsets that truncate the melting regime, such as large transforms, are associated with diminished extents of melting within the mantle. Petrological evidence obtained thus far is not consistent with active upwelling to explain crustal thickness variations along nontransform offset bounded segments.},
	doi = {10.1029/97JB00391},
	url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/97JB00391},
	author = {Jennifer R. Reynolds and Charles H. Langmuir}
}
@article {LANGMUIR199769,
	title = {Hydrothermal vents near a mantle hot spot: the Lucky Strike vent field at 37{\textdegree}N on the Mid-Atlantic Ridge},
	journal = {Earth and Planetary Science Letters},
	volume = {148},
	number = {1},
	year = {1997},
	pages = {69 - 91},
	abstract = {The Lucky Strike hydrothermal field occurs in the summit basin of a large seamount that forms the shallow center of a 65 km long ridge segment near 37{\textdegree}N on the Mid-Atlantic Ridge. The depth and chemistry of the ridge segment are influenced by the Azores hot spot, and this hydrothermal field is the first Atlantic site found on crust that is dominated by a hot spot signature. Multiple hydrothermal vents occur over an area of at least 300 m by 700 m. Vent morphologies range from flanges and chimneys with temperatures of 200{\textendash}212{\textdegree}C, to black smoker chimneys with temperatures up to 333{\textdegree}C. Cooler fluids from northern vents have higher chlorinities and lower gas volumes, while hotter, southern fluids have chlorinities 20\% below seawater with higher gas volumes, suggesting phase separation has influenced their compositions. All gas volumes in fluids are higher than those at TAG and Snake Pit hydrothermal fields. Black smokers exhibit their typical mineralogy, except that barite is a major mineral, particularly at lower-temperature sites, which contrasts with previously investigated Atlantic sites. The fluid chemistry, distribution of the relict sulfide deposits on the seamount summit in the areas investigated using DSV Alvin, and contact relationships between active vent sites and surrounding basaltic and sulfide substrate suggest that the hydrothermal system has a long history and may have recently been rejuvenated. Fauna at the Lucky Strike vent sites are dominated by a new species of mussel, and include the first reported sea urchins. The Lucky Strike biological community differs considerably from other vent fauna at the species level and appears to be a new biogeographic province. The Lucky Strike field helps to constrain how variations in the basaltic substrate influence the composition of hydrothermal fluids and solids, because basalt compositions at Lucky Strike are 10{\textendash}30 times enriched in incompatible elements compared to other Atlantic hydrothermal sites such as TAG, Snake Pit and Broken Spur. The incompatible element},
	issn = {0012-821X},
	doi = {https://doi.org/10.1016/S0012-821X(97)00027-7},
	url = {http://www.sciencedirect.com/science/article/pii/S0012821X97000277},
	author = {Langmuir, C. and S. Humphris and D. Fornari and C. Van Dover and K. Von Damm and Tivey, M.K. and D. Colodner and J.-L. Charlou and D. Desonie and Wilson, C. and Y. Fouquet and G. Klinkhammer and H. Bougault}
}
@article {NIU1997251,
	title = {The origin of abyssal peridotites: a new perspective},
	journal = {Earth and Planetary Science Letters},
	volume = {152},
	number = {1},
	year = {1997},
	pages = {251 - 265},
	abstract = {Abyssal peridotites have been interpreted to be residues of mantle melting beneath ocean ridges. Recent experimental data and models of mantle melting allow quantitative tests of this hypothesis. The tests show that abyssal peridotites are not purely melting residues. Their modal proportions and whole-rock compositions have far more olivine than would be predicted from melting models. Nonetheless, the correlations between modal proportions of olivine and residual mineral chemistry, and the relationship between associated basalt and peridotite compositions, require an important role for melting. We suggest that abyssal peridotite compositions result from a combination of melting and crystallization processes that are both a natural response to ascent of solid and melt beneath an ocean ridge. Different extents of melting create a range of residual peridotite and mantle melt compositions. The buoyant melts migrate upwards, where they encounter the surface thermal boundary layer and crystallize olivine. The greater the ambient extent of melting of the mantle, the higher the normative olivine contents of the melt, and the more melt is produced. Hence greater extents of melting lead to more olivine crystallization at shallow levels. This correlation between melting and crystallization within the mantle preserves the observed relationships between peridotite modes and mineral compositions. Significant implications of these results are: (1) the bulk composition of the oceanic crust differs from the primary melt compositions produced by partial melting of the mantle because of olivine crystallization at the thermal boundary layer; (2) the actual thickness of igneous crust may be variably thinner than would be calculated assuming total melt extraction; and (3) peridotite modes can be used to infer polybaric mantle melting reactions only if the accumulated olivine is removed appropriately.},
	keywords = {mantle, mid-ocean ridge basalts, mid-ocean ridges, partial melting, peridotites},
	issn = {0012-821X},
	doi = {https://doi.org/10.1016/S0012-821X(97)00119-2},
	url = {http://www.sciencedirect.com/science/article/pii/S0012821X97001192},
	author = {Yaoling Niu and Charles H. Langmuir and Rosamond J. Kinzler}
}
@article {Bourdon1996ConstraintsOM,
	title = {Constraints on mantle melting at mid-ocean ridges from global 238U{\textendash}230Th disequilibrium data},
	journal = {Nature},
	volume = {384},
	year = {1996},
	pages = {231-235},
	author = {Bernard Bourdon and Alan Zindler and Tim Elliott and Charles H. Langmuir}
}
@article {RYAN1996415,
	title = {The boron systematics of intraplate lavas: Implications for crust and mantle evolution},
	journal = {Geochimica et Cosmochimica Acta},
	volume = {60},
	number = {3},
	year = {1996},
	pages = {415 - 422},
	abstract = {Ocean island basalts (OIBs) possess uniformly low B contents, and lower B/Nb and B/K2O ratios than mid-ocean ridge basalts (MORBs). As with Pb, B enrichments in both MORBs and OIBs are substantially lower than those of arc volcanics or continental rocks. The devolatilization of subducting plates and associated arc magmatism efficiently segregate B into crustal reservoirs and return large volumes of B-depleted material to the deep mantle. Subduction processes (and presumably arc volcanism) have thus played a major role in continental crust formation. While B is depleted in OIBs relative to either MORBs or arc lavas, OIB samples representing EM and HIMU isotopic reservoirs, often ascribed to the effects of ancient subducted materials, cannot be distinguished from other OIBs in terms of B abundances or B ratios. Our results suggest either (1) the differential depletion in B of two distinct mantle reservoirs, one of which now produces MORBs, and the other OIBs or (2) the episodic or continuous mixing of OIB mantle sources with B-depleted subducted materials. The geochemical processes responsible for the isotopic heterogeneity of intraplate lavas may all serve to segregate B from the mantle into crustal rocks and other surface reservoirs.},
	issn = {0016-7037},
	doi = {https://doi.org/10.1016/0016-7037(95)00402-5},
	url = {http://www.sciencedirect.com/science/article/pii/0016703795004025},
	author = {Jeffrey G. Ryan and William P. Leeman and Julie D. Morris and Charles H. Langmuir}
}
@article {BOURDON1996175,
	title = {Ridge-hotspot interaction along the Mid-Atlantic Ridge between 37{\textdegree}30' and 40{\textdegree}30'N: the UTh disequilibrium evidence},
	journal = {Earth and Planetary Science Letters},
	volume = {142},
	number = {1},
	year = {1996},
	pages = {175 - 189},
	abstract = {This study reports UTh disequilibrium data obtained by mass spectrometry for basaltic glasses collected along the Azores platform portion of the Mid-Atlantic Ridge (37{\textdegree}30'{\textendash}40{\textdegree}30'N), a region characterized by both a geochemical and bathymetric gradient. High Th and U concentrations, as well asTh/U ratios, document an enriched geochemical signature. (230Th238U) activity ratios range from 1.20 to 1.35 and are thus systematically larger than most EPR MORBs reported in the literature. (230Th232Th) activity ratios show remarkable homogeneity for multiple samples taken from single dredge hauls. Additionally, samples with the highest Th concentrations (2.4 ppm) have among the highest Th isotope ratios. Taken together, these observations rule out assimilation of230Th-rich sediment as an explanation for the230Th238U systematics. The relatively large230Th excesses in the erupted lavas may be related to the influence of the enriched Azores mantle plume source. The lack of observed correlations between230Th excess and trace element and isotopic indices of source enrichment, however, rules out source composition as an explanation for the variations in (230Th238U). Excess230Th is correlated with the axial depth of the ridge in the study area, with the shallowest portions showing the largest extents of disequilibrium. This may reflect more melting in the presence of garnet for the shallow segments, and suggests that melting begins well within the garnet peridotite stability field (\~{} 35 kbar) in the mantle beneath the Azores segment of the MAR. At the ridge segment scale,230Th excesses tend to be smaller near segment boundaries. This could reflect differences in the melting process or less frequent magmatism in these zones. These results demonstrate the potential for UTh systematics to constrain the depth and degree of melting as well as the rate of mantle upwelling, even in the presence of source chemical heterogeneity.},
	keywords = {equilibrium, hot spots, Mid-Atlantic ridge, mid-ocean ridges},
	issn = {0012-821X},
	doi = {https://doi.org/10.1016/0012-821X(96)00092-1},
	url = {http://www.sciencedirect.com/science/article/pii/0012821X96000921},
	author = {B. Bourdon and Langmuir, C.H. and A. Zindler}
}
@article {LEEVANDOVER19961509,
	title = {Biology of the Lucky Strike hydrothermal field},
	journal = {Deep Sea Research Part I: Oceanographic Research Papers},
	volume = {43},
	number = {9},
	year = {1996},
	pages = {1509 - 1529},
	abstract = {Newly discovered hydrothermal vent communities at Lucky Strike on the Mid-Atlantic Ridge (37{\textdegree}18'N, 32{\textdegree}16'W) are comprised of an invertebrate fauna sufficiently different from known vent faunas of TAG and Snake Pit to consider Lucky Strike part of a new biogeographic province. The dominant component of the fauna is a new species of mussel, and the most unusual feature of the fauna is an echinoid echinoderm, Echinus sp. An abundance of small mussels (< 5 mm) indicates a recent recruitment event at Lucky Strike, and modal analysis of length-frequency data indicate a discontinuous recruitment process in space and time.},
	issn = {0967-0637},
	doi = {https://doi.org/10.1016/S0967-0637(96)00051-9},
	url = {http://www.sciencedirect.com/science/article/pii/S0967063796000519},
	author = {Cindy Lee Van Dover and Daniel Desbruy{\`e}res and Michel Segonzac and Thierry Comtet and Luiz Saldanha and Aline Fiala-Medioni and Charles Langmuir}
}
@article {631644,
	title = { Minute mantle melts.  },
	journal = {Nature},
	volume = {375},
	year = {1995},
	pages = {274-275.},
	author = {Kinzler, R. and Langmuir, C.}
}
@article {631640,
	title = {Deep sea thrills, review of Explorations: My Quest for Adventure and Discovery Under the Sea, R. D. Ballard with M. McConnell, Hyperion.    },
	journal = { Nature },
	volume = {pp 407},
	year = {1995},
	pages = {376, 221},
	author = {Langmuir, C.}
}
@article {doi:10.1029/95JB01148,
	title = {The meaning of {\textquotedblleft}mean F{\textquotedblright}: Clarifying the mean extent of melting at ocean ridges},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {100},
	number = {B8},
	year = {1995},
	pages = {15045-15052},
	abstract = {In a recent paper, Forsyth (1993) concludes that fractional melting leads to unexpected relationships between the degree of melting (F), crustal thickness, and the depth of melting beneath mid-ocean ridges. Specifically, he suggests that a commonly cited rule of thumb, that 10\% mean melting of a 60-km column of mantle leads to 6 km of crustal thickness (Klein et al., 1991; Langmuir et al., 1992), is incorrect for fractional melting of the mantle. Here we show that the rule of thumb remains valid for Langmuir et al.{\textquoteright}s definition of mean F and that confusion has arisen because there has been disagreement on the definition of mean F. Plank and Langmuir (1992) have defined mean F as the ratio of the mass flux of melt added to the oceanic crust to the mass flux of mantle entering the melting region; Forsyth (1993) has defined mean F as the average degree of melting of all pooled melt increments, with degree calculated at the last point of chemical equilibration. We show here that both definitions of mean F are valid conceptually and mathematically, clarify the differences between them, show how they relate differently to observables such as crustal thickness and crustal composition, and propose nomenclature to clarify usage in the future (FB for Plank and Langmuir{\textquoteright}s bulk melt fraction and Fv for Forsyth{\textquoteright}s mean value).},
	doi = {10.1029/95JB01148},
	url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/95JB01148},
	author = {Terry Plank and Spiegelman, Marc and Charles H. Langmuir and Forsyth, Donald W.}
}
@article {631655,
	title = {Reply to Varne.  },
	journal = { Nature },
	volume = {367},
	year = {1994},
	pages = {224-225.},
	author = {Plank, T. and Langmuir, C.}
}
@article {631654,
	title = {Water and the solid Earth. },
	journal = {Nature},
	volume = {369},
	year = {1994},
	pages = {704-705.},
	author = {Langmuir, C.}
}
@article {631651,
	title = {Small-scale spatial and temporal variations in mid-ocean ridge crest magmatic processes. },
	journal = {Geology},
	volume = {22},
	year = {1994},
	pages = {375-379.},
	author = {Perfit, M. and D. Fornari and M. Smith and J. Bender and Langmuir, C. and Haymon, R.}
}
@article {631648,
	title = { How large is the mantle source of ocean island basalts? },
	journal = {Mineralogical Magazine},
	volume = {58},
	year = {1994},
	pages = {336-339.},
	author = {Goldstein, S. \& Pinker, S. and Miller, D. and Langmuir, C. and Hofmann, A.}
}
@article {Miller1994CeriumleadAL,
	title = {Cerium/lead and lead isotope ratios in arc magmas and the enrichment of lead in the continents},
	journal = {Nature},
	volume = {368},
	year = {1994},
	pages = {514-520},
	author = {Daniel Menachem Miller and Steven L. Goldstein and Charles H. Langmuir}
}
@article {CHRISTIE199447,
	title = {Automated XY plots from Microsoft Excel},
	journal = {Computers \& Geosciences},
	volume = {20},
	number = {1},
	year = {1994},
	pages = {47 - 52},
	abstract = {We present a macro program which greatly simplifies the process of making X{\textendash}Y (scatter) and triangular plots using the spreadsheet program Microsoft Excel{\textregistered}. The program draws on user-defined {\textquotedblleft}type-plots{\textquotedblright} to establish plot format, allowing a great amount of flexibility in style and presentation. Predefined templates can be used to define fields or lines for specific purposes and these can be retained easily from plot to plot facilitating rapid comparison of different data sets. The program requires only the addition of some simple control characters to be able to draw data from existing spreadsheets with little or no reformatting.},
	keywords = {Graphing, Microsoft Excel, plots, Plotting, Scatter plots, Spreadsheets, Triangular plots},
	issn = {0098-3004},
	doi = {https://doi.org/10.1016/0098-3004(94)90095-7},
	url = {http://www.sciencedirect.com/science/article/pii/0098300494900957},
	author = {David M. Christie and Charles H. Langmuir}
}
@article {631662,
	title = { Lucky Strike / Alvin Expedition,     },
	journal = {Cruise Report.},
	volume = {Technical Report No.},
	number = { LDEO-93-2},
	year = {1993},
	author = {Langmuir, C.}
}
@article {631660,
	title = {Deep Thoughts on the Mantle. },
	journal = {Nature},
	volume = {364},
	year = {1993},
	pages = {191-192.},
	author = {Langmuir, C.}
}
@article {Plank1993TracingTE,
	title = {Tracing trace elements from sediment input to volcanic output at subduction zones},
	journal = {Nature},
	volume = {362},
	year = {1993},
	pages = {739-743},
	author = {Terry A. Plank and Charles H. Langmuir}
}
@article {RYAN19931489,
	title = {The systematics of boron abundances in young volcanic rocks},
	journal = {Geochimica et Cosmochimica Acta},
	volume = {57},
	number = {7},
	year = {1993},
	pages = {1489 - 1498},
	abstract = {Boron behaves as a highly incompatible trace element in oceanic settings, while in arcs it shows unique systematics indicative of fluid-rock interactions. Boron analyses conducted on well-characterized mid-ocean ridge basalt (MORB) suites show that B approximates K most closely in its solid/ melt distribution behavior, with inferred bulk distribution coefficients of 0.004-0.009 during melting in the mantle and up to 0.07 during low-pressure crystallization. During differentiation processes in volcanic arc lavas B and K also vary similarly, but the B enrichments in basalts from different arc volcanoes are highly heterogeneous relative to those of K, Be, or other incompatibles. Boron shows strong affinities for fluids such as are liberated during the devolatilization of subducting slabs. Boron enrichments correlate directly with extents of melting in arc basalts, and inversely with the enrichments of most other lithophile trace elements. Boron enrichments at arcs are lower in those volcanoes that sample deeper portions of the slab, becoming indistinguishable from MORBs in the rearmost volcanic centers. That such B depletions are evident in lavas entails that magmatic processes and other transport mechanisms efficiently flush B through the mantle wedge and return it to surface reservoirs. The great mobility of boron apparent from the arc data precludes any long-term B enrichment in the sub-arc mantle and requires the existence of strong return fluxes for B in addition to arc volcanism.},
	issn = {0016-7037},
	doi = {https://doi.org/10.1016/0016-7037(93)90008-K},
	url = {http://www.sciencedirect.com/science/article/pii/001670379390008K},
	author = {Jeffrey G. Ryan and Charles H. Langmuir}
}
@article {631663,
	title = {Evaluation of the relationships among segmentation, hydrothermal activity and petrological diversity of the Mid-Atlantic Ridge},
	journal = {Cruise Report},
	volume = {Technical Report  No.},
	number = { LDEO-92-3},
	year = {1992},
	author = {Langmuir, C.}
}
@article {doi:10.1029/91JB02150,
	title = {The importance of parental magma composition to calc-alkaline and tholeiitic evolution: Evidence from Umnak Island in the Aleutians},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {97},
	number = {B1},
	year = {1992},
	pages = {321-343},
	abstract = {Okmok and Recheshnoi are adjacent volcanoes on the island of Umnak in the Aleutian Arc. Ninety-five new chemical analyses of lavas from the two volcanoes show that Okmok exhibits a classical tholeiitic and Recheshnoi a calc-alkaline differentiation trend. Both volcanoes have erupted lavas that range in composition from basalt to rhyolite. This allows investigation of differences in both the differentiation systematics and the parental magma compositions. In contrast to the predictions of many recent models for calc-alkaline and tholeiitic volcanism, the major and trace element data show that the parental magmas for the two volcanoes have different compositions. These different parental compositions might themselves be produced by in situ differentiation or other complex fractionation processes from a very magnesian parental magma (16\% MgO) with Okmok being derived by low-pressure fractionation and Recheshnoi by in situ fractionation at higher pressures. An alternative and simpler explanation is that the inferred high-MgO Okmok parent and the Recheshnoi parent are derived by different extents of melting in the mantle wedge. Modelling based on the rare earth elements suggests approximately 7\% melting for the calc-alkaline parent and 20\% for the tholeiitic parent. For these two volcanoes therefore, there may be a correlation between extent of melting and the tendency to follow a calc-alkaline or tholeiitic differentiation trend. Larger enrichments of highly fluid-mobile elements such as boron and cesium in the tholeiitic Okmok source suggest that variability in the volume of fluid flux from the slab may be responsible for the different extents of melting. If the partial melting model is applied generally to the Aleutian Arc, it provides an alternative explanation for the volcanic regularities of the arc described by Kay et al. (1982). Smaller extents of melting lead to less melt, fractionation at higher pressures, often including hydrous phases, a preponderance of plutonic rather than volcanic rocks, and smaller calc-alkaline volcanoes. Large tholeiitic volcanoes are often associated with fracture zones on the subducting Pacific plate (Kay et al., 1982; Marsh, 1982). Since fracture zones are more extensively altered than average oceanic crust and might also serve as sediment traps, they could serve as sources of a larger volatile flux from the slab, leading to greater extents of melting and large, tholeiitic volcanoes. If this explanation is correct, then the origin of the volcanic segmentation of the arc may be found within the subducted slab. This contrasts with the alternative model of control by the stress regime of the overlying plate (Kay et al., 1982; Singer and Myers, 1990; Kay and Kay, 1991). Inferences from Okmok and Recheshnoi may also apply to global variations in convergent margin chemistry. In general, arcs built On thick crust tend to be more calc-alkaline in character. On the Basis of the negative correlation between convergent margin crustal thickness and inferred extent of melting (Plank and Langmuir, 1988), lower extents of melting may contribute to a tendency towards calc-alkaline differentiation on a global basis.},
	doi = {10.1029/91JB02150},
	url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/91JB02150},
	author = {Miller, Daniel M. and Charles H. Langmuir and Steven L. Goldstein and Franks, Andrew L.}
}
@article {doi:10.1029/92JB01769,
	title = {Effects of the melting regime on the composition of the oceanic crust},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {97},
	number = {B13},
	year = {1992},
	pages = {19749-19770},
	abstract = {The physical form of the melting regime and the mechanisms of melt extraction influence the composition of magmas erupted at ocean ridges. We investigate aspects of this relationship, beginning with the assumption that melts can be extracted from the melting regime without significant reequilibration during their passage to the surface. The ocean crust thus represents a mixture of the individual melts. Many melting regimes lead to the same {\textquotedblleft}residual mantle column{\textquotedblright} (RMC), defined as a vertical section through the mantle external to the melting regime. The RMC is the integrated result of melt extraction and is useful in evaluating the geochemical effects of many different types of melting regimes. Consideration of the RMC shows that the {\textquotedblleft}shape{\textquotedblright} of the melting regime is not necessarily an important parameter in affecting the composition of the ocean crust. The important parameters are the way mantle flows through the melting regime and the relationship between melt fraction and pressure during adiabatic melting. Calculating the volume and composition of the ocean crust can be reduced to a simple mixing problem. Virtually all ridge models predict continuous mixing of melts from the solidus to the maximum extent of melting. Given these boundary conditions, even complex melting regimes lead to geochemical results that are similar to those produced by batch melting. Thus batch melting may approximate the net effects of the melting process remarkably well. An important exception to these generalizations is binary mixing between melts of very different composition. This is possible beneath ocean ridges if very low degree melts, formed at the volatile-present solidus, mix with higher-degree melts formed directly beneath the ridge. There are limitations to the effectiveness of such a mixing process because the source volume for the low-degree melts is constrained by the finite pressure interval between the dry and volatile-present solidi of the mantle. These constraints place an upper limit of a factor of 5 on the incompatible element enrichment that can be explained by such mixing. This is a small factor relative to the global variability of mid-ocean ridge basalts. A few local regions, however, show major and trace element covariations that may be consistent with this type of mixing. Adequate data sets to fully test the possibility are lacking. If such mixing occurs, there must be a physical mechanism to focus the lowest degree melts from the furthest reaches of the melting regime into the mantle directly beneath the ridge axis. The physical difficulties associated with horizontal transport of low-degree melts over tens to hundreds of kilometers are imposing and suggest that alternative models should be seriously considered.},
	doi = {10.1029/92JB01769},
	url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/92JB01769},
	author = {Terry Plank and Charles H. Langmuir}
}
@article {Reynolds1992SpatialAT,
	title = {Spatial and temporal variability in the geochemistry of basalts from the East Pacific Rise},
	journal = {Nature},
	volume = {359},
	year = {1992},
	pages = {493-499},
	author = {Jennifer R. Reynolds and Charles H. Langmuir and John Bender and Kirn A. Kastens and William B. F. Ryan}
}
@article {doi:10.1029/90JB01384,
	title = {Geochemistry of basalts from the southeast Indian Ridge, 115{\textdegree}E{\textendash}138{\textdegree}E},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {96},
	number = {B2},
	year = {1991},
	pages = {2089-2107},
	abstract = {The ocean basin south of Australia contains the Australian-Antarctic Discordance, an anomalously deep portion of the Southeast Indian Ridge that marks a boundary between isotopic provinces characteristic of the Indian and Pacific oceans. Samples recovered from the ridge within the discordance display unusual chemical compositions compared to normal mid-ocean ridge basalt (N-MORB) of the same MgO contents, including low iron, high silica, and high sodium abundances and elevated abundances of highly incompatible trace elements. In contrast, samples from the ridge east of the discordance, where the ridge is of average axial depth, display major and trace element systematics more typical of N-MORB. Major and moderately incompatible trace elements show no evidence of a discontinuity in source composition corresponding to the location of the known isotopic discontinuity within the discordance. Ratios of highly incompatible trace elements, however, reveal a gradational change in the range of values across the location of the isotopic discontinuity. Modelling of along-strike variations in major element chemistry suggest they may result from systematic variations in the extent and pressure of melting. The lowest solidus pressures and least extents of melting occur in the mantle beneath the discordance, supporting geophysical inferences based on bathymetric, gravity, and seismic evidence that the discordance overlies a region of cooler mantle temperatures.},
	doi = {10.1029/90JB01384},
	url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/90JB01384},
	author = {Emily M. Klein and Charles H. Langmuir and Hubert Staudigel}
}
@article {Langmuir1990OceanRS,
	title = {Ocean ridges spring surprises},
	journal = {Nature},
	volume = {344},
	year = {1990},
	pages = {585-586},
	author = {Charles H. Langmuir}
}
@article {SCOTTWEAVER19901,
	title = {Calculation of phase equilibrium in mineral-melt systems},
	journal = {Computers \& Geosciences},
	volume = {16},
	number = {1},
	year = {1990},
	pages = {1 - 19},
	abstract = {This paper presents a general method for the calculation of mineral-melt phase equilibria based on mass balance, stoichiometry, and single component distribution coefficients. An algorithm for the practical application of this method is developed, and a computer program using this algorithm for calculation of phase stability, phase proportions, and phase composition has been included. The program includes both equilibrium and fractional models for melting and crystallization. This particular implementation incorporates a specific distribution coefficient model for olivine, plagioclase, and clinopyroxene crystallization in basaltic systems. Calculated results from the program agree with those from experiments on terrestrial basaltic compositions. The program has been designed to be modified easily to incorporate other distribution coefficient models for detailed application to specific data sets. In this way, the program should be able to be applied to diverse compositions, phase assemblages, and physical processes of crystal/liquid interaction. In general, the algorithm and its implementation provide a practical method for calculating equilibria in multicomponent, mineral-melt systems.},
	keywords = {FORTRAN 66, Mass balance, Mineral-melt systems, Phase-equilibrium algorithm, Stoichiometry},
	issn = {0098-3004},
	doi = {https://doi.org/10.1016/0098-3004(90)90074-4},
	url = {http://www.sciencedirect.com/science/article/pii/0098300490900744},
	author = {J. Scott Weaver and Charles H. Langmuir}
}
@article {FRYER1990161,
	title = {Petrology and geochemistry of lavas from the Sumisu and Torishima backarc rifts},
	journal = {Earth and Planetary Science Letters},
	volume = {100},
	number = {1},
	year = {1990},
	pages = {161 - 178},
	abstract = {Thirteen dredge hauls from the active Sumisu and Torishima rift grabens west of the Izu-Bonin arc at about 30{\textdegree}{\textendash}31{\textdegree}N, 140{\textdegree}E, recovered a suite of tholeiitic basalts to sodic rhyolites. Volcanism occurs along tensional faults within and bounding the rift grabens and along the transfer zones between adjoining rift segments. The Sumisu and Torishima rift lavas differ significantly from the lavas of the adjacent arc volcanic centers in having lowerAl2O3/Na2O,Ba/Zr,V/Ti, andBa/Ce and higher abundances of the rare earth elements. The rift lavas also have characteristics of backarc basin basalts, in that they are enriched in Al2O3, and depleted in total iron and TiO2 relative to mid-ocean ridge basalt, characteristics which are consistent with a higher water content in the source. Thus, the model of a progressive change in backarc basin basalt composition from arc-like to mid-ocean ridge-like, as a function of evolution of the basin, as has been suggested from many backarc regions, is not generally applicable. The comparison of the Sumisu and Torishima rift lavas with Mariana backarc basin lavas indicates that backarc basin basalts differ in composition from one basin to another. The comparison of these backarc basin suites with mid-ocean ridge suites from similar axial depths indicates that the overall control over the spectrum of backarc basin basalt compositions may be different extents of melting of the mantle. The Sumisu and Torishima rift lavas formed by a slightly higher extent of melting than the Mariana backarc basin basalts, a phenomenon which is related to the depth of the ridge segments. Furthermore, the data suggest a systematically higher extent of melting in the arc lavas than in the backarc lavas for both of these arc/backarc systems, consistent with a greater flux of water beneath the arc than beneath the backarc region.},
	issn = {0012-821X},
	doi = {https://doi.org/10.1016/0012-821X(90)90183-X},
	url = {http://www.sciencedirect.com/science/article/pii/0012821X9090183X},
	author = {Patricia Fryer and Brian Taylor and Charles H. Langmuir and Alfred G. Hochstaedter}
}
@article {TAYLOR1990127,
	title = {Alvin-SeaBeam studies of the Sumisu Rift, Izu-Bonin arc},
	journal = {Earth and Planetary Science Letters},
	volume = {100},
	number = {1},
	year = {1990},
	pages = {127 - 147},
	abstract = {Bimodal volcanism, normal faulting, rapid sedimentation, and hydrothermal circulation characterize the rifting of the Izu-Bonin arc at 31{\textdegree}N. Analysis of the zigzag pattern, in plan view, of the normal faults that bound Sumisu Rift indicates that the extension direction (080{\textdegree} {\textpm} 10{\textdegree}) is orthogonal to the regional trend of the volcanic front. Normal faults divide the rift into an inner rift on the arc side, which is the locus for maximum subsidence and sedimentation, and an outer rift further west. Transfer zones that link opposing master faults and/or rift flank uplifts further subdivide the rift into three segments along strike. Volcanism is concentrated along the ENE-trending transfer zone which separates the northern and central rift segments. The differential motion across the zone is accommodated by interdigitating north-trending normal faults rather than by ENE-trending oblique-slip faults. Volcanism in the outer rift has built 50{\textendash}700 m high edifices without summit craters whereas in the inner rift it has formed two multi-vent en echelon ridges (the largest is 600 m high and 16 km long). The volcanism is dominantly basaltic, with compositions reflecting mantle sources little influenced by arc components. An elongate rhyolite dome and low-temperature hydrothermal deposits occur at the en echelon step in the larger ridge, which is located at the intersection of the transfer zone with the inner rift. The chimneys, veins, and crusts are composed of silica, barite and iron oxide, and are of similar composition to the ferruginous chert that mantles the Kuroko deposits. A 1.2-km transect of seven alvin heat flow measurements at 30{\textdegree}48.5'N showed that the inner-rift-bounding faults may serve as water recharge zones, but that they are not necessarily areas of focussed hydrothermal outflow, which instead occurs through the thick basin sediments. The rift basin and arc margin sediments are probably dominated by permeable rhyolitic pumice and ash erupted from submarine arc calderas such as Sumisu and South Sumisu volcanoes.},
	issn = {0012-821X},
	doi = {https://doi.org/10.1016/0012-821X(90)90181-V},
	url = {http://www.sciencedirect.com/science/article/pii/0012821X9090181V},
	author = {B. Taylor and G. Brown and P. Fryer and J.B. Gill and A.G. Hochstaedter and H. Hotta and Langmuir, C.H. and M. Leinen and A. Nishimura and T. Urabe}
}
@article {doi:10.1029/JB094iB04p04241,
	title = {Local versus global variations in ocean ridge basalt composition: A reply},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {94},
	number = {B4},
	year = {1989},
	pages = {4241-4252},
	doi = {10.1029/JB094iB04p04241},
	url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/JB094iB04p04241},
	author = {Emily M. Klein and Charles H. Langmuir}
}
@article {Langmuir1989GeochemicalCO,
	title = {Geochemical consequences of in situ crystallization},
	journal = {Nature},
	volume = {340},
	year = {1989},
	pages = {199-205},
	author = {Charles H. Langmuir}
}
@article {631700,
	title = {Isotope evidence of mantle convection boundary at the Australian-Antarctic Discordance},
	journal = {Nature},
	volume = {333},
	year = {1988},
	pages = {623-629},
	author = {Klein, E and Langmuir, C. and Zindler, A and Staudigel, H and Hamelin, B}
}
@article {Klein1988IsotopeEO,
	title = {Isotope evidence of a mantle convection boundary at the Australian-Antarctic Discordance},
	journal = {Nature},
	volume = {333},
	year = {1988},
	pages = {623-629},
	author = {Emily M. Klein and Charles H. Langmuir and Alan Zindler and Hubert Staudigel and Bruno Hamelin}
}
@article {RYAN1988237,
	title = {Beryllium systematics in young volcanic rocks: Implications for 10Be**LDGO contribution No. 4237.},
	journal = {Geochimica et Cosmochimica Acta},
	volume = {52},
	number = {1},
	year = {1988},
	pages = {237 - 244},
	abstract = {Beryllium is an incompatible trace element that closely parallels neodymium in its geochemical behavior. Be analyses conducted on well-characterized oceanic and arc volcanic rock suites, as well as on marine sediments, suggest a bulk solid/liquid distribution coefficient of 0.03{\textendash}0.06 for melting of the mantle and crystallization of basalts. The Be/Nd ratio for many volcanic rocks from diverse tectonic environments is approximately .05, similar to the ratio in chondrites. Be data for samples from volcanic arcs show that there are significant variations in 10Be/9Be among different arcs, and that variations in 10Be are not due to variations in Be concentration alone. For at least one volcano (Bogoslof), the 10Be/9Be ratio is constant for samples that vary by a factor of three in both their Be and 10Be concentrations, suggesting that 10Be is an inherited magmatic signature and not simply a result of contamination near the surface. In addition, the Be, Nd and Pb isotope systems for this volcano are all consistent with a model in which small amounts of sediment were incorporated into the Bogoslof source region{\textemdash}provided the mantle wedge has the isotopic characteristics of depleted MORB. Since 10Be exists only in the uppermost tens of meters of oceanic sediments, the data suggest an efficient return flux of sediment to the mantle at subduction zones.},
	issn = {0016-7037},
	doi = {https://doi.org/10.1016/0016-7037(88)90073-7},
	url = {http://www.sciencedirect.com/science/article/pii/0016703788900737},
	author = {Jeffrey G. Ryan and Charles H. Langmuir}
}
@article {PLANK1988349,
	title = {An evaluation of the global variations in the major element chemistry of arc basalts},
	journal = {Earth and Planetary Science Letters},
	volume = {90},
	number = {4},
	year = {1988},
	pages = {349 - 370},
	abstract = {Arc volcanoes occur at convergent margins with a wide range in subduction parameters, and variations in these parameters might be expected to lead to variations in the chemistry of magmas parental to arcs. Major element analyses from approximately 100 volcanic centers within 30 arcs, normalized to 6\% MgO to minimize the effects of crystal fractionation, display wide variations. Na2O and CaO at 6\% MgO (Na6.0 and Ca6.0) correlate remarkably well with the thickness of the overlying crust. These systematics are consistent with two possible models. In the first model, the crust behaves as a chemical filter; where the crust is thick, magmas crystallize at higher pressure and interact more extensively with the arc crust. Modeling of high-pressure crystallization and assimilation, however, does not reproduce the associated variations in Na6.0 and Ca6.0 without calling upon complicated combinations of fractionating phases and assimilants. In the second model, crustal thickness determines the height of the mantle column available for melting beneath arc volcanoes. If melting begins beneath arcs at similar depths, then the column of mantle that undergoes decompression melting is much shorter beneath the thickest arc crust. The shorter mantle column for arcs built on thick crust will lead to smaller extents of melting in the mantle, and hence higher Na6.0 and lower Ca6.0 in the parental magmas. Modeling shows that variations in the extent of melting in the mantle can easily account for the associated variations in Ca6.0 and Na6.0. The abundances of the other major elements at 6\% MgO do not correlate well with crustal thickness, or any other subduction parameter. Co-variation of some of these other major elements (e.g., Si6.0 and Fe6.0) within individual arcs suggests that they are strongly influenced by local crustal level processes that obscure partial melting systematics. Correction for the crustal processes improves the relationship between Na6.0 and Ca6.0 that is so readily explained by partial melting. The extents of melting in the mantle beneath arc volcanoes estimated from the ranges in Na6.0 and Ca6.0 are remarkably similar to those estimated beneath mid-ocean ridges. This observation provides further evidence that the mantle wedge, and not the slab, melts beneath arc volcanic fronts.},
	issn = {0012-821X},
	doi = {https://doi.org/10.1016/0012-821X(88)90135-5},
	url = {http://www.sciencedirect.com/science/article/pii/0012821X88901355},
	author = {Terry Plank and Charles H. Langmuir}
}
@article {631701,
	title = {Global Correlations of Ocean ridge basalt chemistry, axial depth, crustal thickness},
	journal = {J. Geophys. Res},
	volume = {92},
	year = {1987},
	pages = {8089-8115},
	author = {Klein, E and Langmuir, C.}
}
@article {631687,
	title = {A magma chamber observed?  },
	journal = {Nature},
	volume = {326},
	year = {1987},
	pages = {15-16},
	author = {Langmuir, C.}
}
@article {631685,
	title = { Geometry and dynamics of magma chambers},
	journal = {The Mid-oceanic Ridge--A Dynamic Global System, Workshop Proceedings, National Academy Press, },
	year = {1987},
	pages = {121-150},
	author = {Detrick, R and Langmuir, C.}
}
@article {631678,
	title = {Ridge subduction and fore-arc volcanism: petrology and geochemistry of rocks dredged from the western Solomon arc and the Woodlark Basin },
	journal = {Marine Geology, Geophysics and Geochemistry of the Woodlark Basin -Solomon Islands, B. Taylor and N. Exon, eds., Circum-Pacific Earth Science Series},
	volume = {7},
	year = {1987},
	pages = {155-226},
	author = {Johnson, R and Jaques, A and Langmuir, C.}
}
@article {631672,
	title = {"Geochemistry and petrology of volcanic rocks from the Woodlark Basin: addressing questions of ridge subduction" },
	journal = {Marine Geology, Geophysics and Geochemistry of the Woodlark Basin - Solomon Islands, B. Taylor and N. Exon, eds.,Circum-Pacific Earth Science Series},
	volume = {7},
	year = {1987},
	pages = { 113-154},
	author = {Perfit, M and Langmuir, C.}
}
@article {doi:10.1029/JB092iB08p08089,
	title = {Global correlations of ocean ridge basalt chemistry with axial depth and crustal thickness},
	journal = {Journal of Geophysical Research: Solid Earth},
	volume = {92},
	number = {B8},
	year = {1987},
	pages = {8089-8115},
	abstract = {Regional averages of the major element chemistry of ocean ridge basalts, corrected for low-pressure fractionation, correlate with regional averages of axial depth for the global system of ocean ridges, including hot spots, cold spots, and back arc basins, as well as {\textquotedblleft}normal{\textquotedblright} ocean ridges. Quantitative consideration of the variations of each major element during melting of the mantle suggests that the global major element variations can be accounted for by \~{}8{\textendash}20\% melting of the mantle at associated mean pressures of 5{\textendash}16 kbar. The lowest extents of melting occur at shallowest depths in the mantle and are associated with the deepest ocean ridges. Calculated mean primary magmas show a range in composition from 10 to 15 wt \% MgO, and the primary magma compositions correlate with depth. Data for Sm, Yb, Sc, and Ni are consistent with the major elements, but highly incompatible elements show more complicated behavior. In addition, some hot spots have anomalous chemistry, suggesting major element heterogeneity. Thermal modeling of mantle ascending adiabatically beneath the ridge is consistent with the chemical data and melting calculations, provided the melt is tapped from throughout the ascending mantle column. The thermal modeling independently predicts the observed relationships among basalt chemistry, ridge depth, and crustal thickness resulting from temperature variations in the mantle. Beneath the shallowest and deepest ridge axes, temperature differences of approximately 250{\textdegree}C in the subsolidus mantle are required to account for the global systematics.},
	doi = {10.1029/JB092iB08p08089},
	url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/JB092iB08p08089},
	author = {Emily M. Klein and Charles H. Langmuir}
}
@article {Shirey1987ThreecomponentIH,
	title = {Three-component isotopic heterogeneity near the Oceanographer transform, Mid-Atlantic Ridge},
	journal = {Nature},
	volume = {325},
	year = {1987},
	pages = {217-223},
	author = {Steven B. Shirey and John Bender and Charles H. Langmuir}
}
@article {RYAN19871727,
	title = {The systematics of lithium abundances in young volcanic rocks},
	journal = {Geochimica et Cosmochimica Acta},
	volume = {51},
	number = {6},
	year = {1987},
	pages = {1727 - 1741},
	abstract = {Lithium is a moderately incompatible trace element in magmatic systems. High precision analyses for lithium conducted on well characterized suites of MORB and ocean island basalts suggest a bulk distribution coefficient of 0.25-0.35 and behavior which is similar to Yb during low pressure fractionation and V during melting, as long as garnet is not an important residual phase. Data for peridotites and basalts suggest a mantle lithium content of about 1.9 ppm and show that significant concentrations of lithium reside in olivine and orthopyroxene, resulting in unusual inter-mineral partitioning of Li and complex relationships between lithium and other incompatible trace elements. The lithium abundances of arc basalts are similar to those of MORB, but their Li/Yb ratios are considerably higher. The high Li/Yb suggests the addition of a Li-rich component to arc sources; relatively low Yb abundances are consistent with the derivation of some arc magmas by larger extents of melting or from a more depleted source than MORB. Although Li is enriched at arcs, K is enriched more, leading to elevated K/Li ratios in arc volcanics. The high K/Li and relatively low La/Yb of primitive arc basalts requires either incorporation of altered ocean crust into arc magma sources, or selective removal of K and Li from subducted sediments. Bulk incorporation of sediments alone does not explain the Li systematics. Data from primitive MORB indicate a relatively low (3{\textendash}4 ppm) Li content for new oceanic crust. Thus, the Li flux from the ocean crust is probably ,
	issn = {0016-7037},
	doi = {https://doi.org/10.1016/0016-7037(87)90351-6},
	url = {http://www.sciencedirect.com/science/article/pii/0016703787903516},
	author = {Jeffrey G Ryan and Charles H. Langmuir}
}
@article {631690,
	title = {Petrologic and tectonic segmentation of the East Pacific Rise from 6{\textdegree}-14{\textdegree}N},
	journal = {Nature},
	volume = {332},
	year = {1986},
	pages = {422-429},
	author = {Langmuir, C. and J. Bender and Batiza, R}
}
@article {631689,
	title = {Ferric/Ferrous ratios and oxygen fugacities of mid-ocean ridge basalt glasses},
	journal = {Earth Planet. Sci. Lett},
	volume = {79},
	year = {1986},
	pages = {397-411},
	author = {Christie, D and Carmichael, I and Langmuir, C.}
}
@article {631691,
	title = {The significance of unusual zoning in olivines from FAMOUS area basalt 527-1-1 },
	journal = {Contrib. Mineral. Petrol},
	volume = {93},
	year = {1985},
	pages = {1-8},
	author = {P. Nabelek and Langmuir, C.}
}
@article {631695,
	title = { Petrogenesis of basalt glasses from the Tamayo region },
	journal = {J. Petrol},
	volume = {25},
	year = {1984},
	pages = {213-254},
	author = {J. Bender and Langmuir, C. and G. Hanson}
}
@article {631694,
	title = { Geochemical variations around transform faults: observations and implications},
	journal = {Earth. Planet. Sci. Lett},
	volume = {69},
	year = {1984},
	pages = {107-127},
	author = {Langmuir, C. and J. Bender}
}
@article {631693,
	title = {Geochemistry of Volcanic Rocks from the Woodlark Basin: Addressing the questions of ridge subduction and a reversal in the polarity of subduction },
	journal = {inSeafloor Spreading Ridge Subduction, Volcanism and Sedimentation in the Offshore Woodlark-Solomons Regions, B. Taylor and N. Exon (eds.), CCOP/SOPAC Technical Rept},
	volume = {34},
	year = {1984},
	pages = {387-467},
	author = {Perfit, M and Langmuir C}
}
@article {631692,
	title = {Igneous petrology and geochemistry of the New Georgia Group forearc area: The magmatic effects of ridge subduction },
	journal = {in Seafloor Spreading Ridge Subduction, Volcanism and Sedimentation in the Offshore Woodlark-Solomons Regions, B. Taylor and N. Exon (eds.), CCOP/SOPAC Technical Rept},
	volume = {34},
	year = {1984},
	pages = {77-185},
	author = {Johnson, R and Jaques, A and Langmuir, C.}
}
@article {176356,
	title = {The polybaric history of FAMOUS basalt 527-1-1: Evidence from Trace Elements in Olivine},
	journal = {Microbeam Analysis},
	year = {1982},
	pages = {151-154},
	author = {P. Nabelek and Langmuir, C. and A. Bence and Roy H. Geiss}
}
@article {176351,
	title = {Calculating mineral-melt equilbria with stoichiometry, mass balance, and single-component distribution coefficients, Springer-Verlag, New York},
	journal = {Thermodynamics of Minerals and Melts, Advances in Physical Geochemistry},
	volume = {1},
	year = {1981},
	pages = {247-271},
	author = {Langmuir, C. and G. Hanson},
	editor = {R. C. Newton and A. Navrotsky and B. J. Wood}
}
@article {176346,
	title = {An evaluation of major element heterogeneity in the mantle sources of basalts},
	journal = {Philos. Trans. of the Royal Society London},
	volume = {A297},
	year = {1980},
	pages = {383-407},
	author = {Langmuir, C. and G. Hanson}
}
@article {176336,
	title = {"Basalts from DSDP Sites 417 A, D: Fractionated melts of a light rare earth depleted source", Washington, D.C. (U.S. Government Printing office)},
	journal = {Initial Reports of the Deep Sea Drilling Project},
	volume = {51},
	year = {1978},
	pages = {1099 - 1111},
	author = {S. Rice and Langmuir, C. and J. Bender and A. Bence and S. Taylor}
}
@article {176321,
	title = {A general mixing equation with applications to Icelandic basalts},
	journal = {Earth Planet. Sci. Lett},
	volume = {37},
	year = {1978},
	pages = {380-392},
	author = {Langmuir, C., and R. Vocke and G. Hanson and S. Hart}
}
@article {176326,
	title = {Modeling of major elements in mantle-melt systems using trace element approaches},
	journal = {Geochim. Cosmochim. Acta},
	volume = {42},
	year = {1978},
	pages = {725-742},
	author = {G. Hanson and Langmuir, C.}
}
@article {176316,
	title = {Petrogenesis of basalts from the FAMOUS area: Mid-Atlantic Ridge.},
	journal = {Earth Planet. Sci. Lett.},
	volume = {36},
	year = {1977},
	pages = {133-156},
	author = {Langmuir, C. and J. Bender and A. Bence and G. Hanson and S. Taylor}
}
