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Sources of dehydration fluids underneath the Kamchatka arc. Nat Commun 2022; 13:4467. [PMID: 35918359 PMCID: PMC9345910 DOI: 10.1038/s41467-022-32211-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Accepted: 07/21/2022] [Indexed: 12/04/2022] Open
Abstract
Fluids mediate the transport of subducted slab material and play a crucial role in the generation of arc magmas. However, the source of subduction-derived fluids remains debated. The Kamchatka arc is an ideal subduction zone to identify the source of fluids because the arc magmas are comparably mafic, their source appears to be essentially free of subducted sediment-derived components, and subducted Hawaii-Emperor Seamount Chain (HESC) is thought to contribute a substantial fluid flux to the Kamchatka magmas. Here we show that Tl isotope ratios are unique tracers of HESC contribution to Kamchatka arc magma sources. In conjunction with trace element ratios and literature data, we trace the progressive dehydration and melting of subducted HESC across the Kamchatka arc. In succession, serpentine (<100 km depth), lawsonite (100–250 km depth) and phengite (>250 km depth) break down and produce fluids that contribute to arc magmatism at the Eastern Volcanic Front (EVF), Central Kamchatka Depression (CKD), and Sredinny Ridge (SR), respectively. However, given the Tl-poor nature of serpentine and lawsonite fluids, simultaneous melting of subducted HESC is required to explain the HESC-like Tl isotope signatures observed in EVF and CKD lavas. In the absence of eclogitic crust melting processes in this region of the Kamchatka arc, we propose that progressive dehydration and melting of a HESC-dominated mélange offers the most compelling interpretation of the combined isotope and trace element data. Fluids released from progressive breakdown of minerals at increasing pressure within a mélange may explain the trace element systematics and stable thallium isotope data of the Kamchatka arc lavas from volcanic front to back arc.
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Zhang Y, Gazel E, Gaetani GA, Klein F. Serpentinite-derived slab fluids control the oxidation state of the subarc mantle. SCIENCE ADVANCES 2021; 7:eabj2515. [PMID: 34826248 PMCID: PMC8626075 DOI: 10.1126/sciadv.abj2515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 10/07/2021] [Indexed: 06/13/2023]
Abstract
Recent geochemical evidence confirms the oxidized nature of arc magmas, but the underlying processes that regulate the redox state of the subarc mantle remain yet to be determined. We established a link between deep subduction-related fluids derived from dehydration of serpentinite ± altered oceanic crust (AOC) using B isotopes and B/Nb as fluid proxies, and the oxidized nature of arc magmas as indicated by Cu enrichment during magma evolution and V/Yb. Our results suggest that arc magmas derived from source regions influenced by a greater serpentinite (±AOC) fluid component record higher oxygen fugacity. The incorporation of this component into the subarc mantle is controlled by the subduction system’s thermodynamic conditions and geometry. Our results suggest that the redox state of the subarc mantle is not homogeneous globally: Primitive arc magmas associated with flat, warm subduction are less oxidized overall than those generated in steep, cold subduction zones.
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Affiliation(s)
- Yuxiang Zhang
- Key Laboratory of Marine Geology and Environment, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, Shandong, China
- Laboratory for Marine Mineral Resources, Qingdao Pilot National Laboratory for Marine Science and Technology, Qingdao, Shandong, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, Shandong, China
| | - Esteban Gazel
- Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY, USA
| | - Glenn A. Gaetani
- Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Frieder Klein
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
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Hafnium isotope constraints on the nature of the mantle beneath the Southern Lau basin (SW Pacific). Sci Rep 2020; 10:17476. [PMID: 33060785 PMCID: PMC7566480 DOI: 10.1038/s41598-020-74565-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 10/01/2020] [Indexed: 11/19/2022] Open
Abstract
New Hf isotope data provide new insights into the nature of the mantle beneath the southern Lau basin, adding new constraints on the displacement process of the Pacific mid-ocean ridge basalt (MORB)-type mantle by the Indian MORB-type mantle. The Hf isotopic ratios (176Hf/177Hf) of submarine lavas from the eastern Lau spreading center (ELSC) range from 0.283194 (εHf = 14.92) to 0.283212 (εHf = 15.54), with an average value of 0.283199 (εHf = 15.11) whereas those from the Valu Fa ridge (VFR) vary from 0.283221 (εHf = 15.88) to 0.283200 (εHf = 15.14), with an average of 0.283214 (15.61), indicating that ELSC lavas have a slightly more radiogenic Hf isotopic composition than VFR lavas. In contrast to the results from previous studies, the new Hf analyses combined with previous Nd isotope data clearly show that both VFR and ELSC have the distinct Hf–Nd isotope composition of the so-called DUPAL isotopic anomaly in the Indian MORB-type mantle. The DUPAL isotopic signature at VFR demonstrates for the first time that the inflow of the Indian MORB-type mantle has reached the southern tip of tectonic propagation in the southern Lau basin.
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Geochemical evidence for a widespread mantle re-enrichment 3.2 billion years ago: implications for global-scale plate tectonics. Sci Rep 2020; 10:9461. [PMID: 32528085 PMCID: PMC7289823 DOI: 10.1038/s41598-020-66324-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 05/12/2020] [Indexed: 11/21/2022] Open
Abstract
Progressive mantle melting during the Earth’s earliest evolution led to the formation of a depleted mantle and a continental crust enriched in highly incompatible elements. Re-enrichment of Earth’s mantle can occur when continental crustal materials begin to founder into the mantle by either subduction or, to a lesser degree, by delamination processes, profoundly affecting the mantle’s trace element and volatile compositions. Deciphering when mantle re-enrichment/refertilization became a global-scale process would reveal the onset of efficient mass transfer of crust to the mantle and potentially when plate tectonic processes became operative on a global-scale. Here we document the onset of mantle re-enrichment/refertilization by comparing the abundances of petrogenetically significant isotopic values and key ratios of highly incompatible elements compared to lithophile elements in Archean to Early-Proterozoic mantle-derived melts (i.e., basalts and komatiites). Basalts and komatiites both record a rapid-change in mantle chemistry around 3.2 billion years ago (Ga) signifying a fundamental change in Earth geodynamics. This rapid-change is recorded in Nd isotopes and in key trace element ratios that reflect a fundamental shift in the balance between fluid-mobile and incompatible elements (i.e., Ba/La, Ba/Nb, U/Nb, Pb/Nd and Pb/Ce) in basaltic and komatiitic rocks. These geochemical proxies display a significant increase in magnitude and variability after ~3.2 Ga. We hypothesize that rapid increases in mantle heterogeneity indicate the recycling of supracrustal materials back into Earth’s mantle via subduction. Our new observations thus point to a ≥ 3.2 Ga onset of global subduction processes via plate tectonics.
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Li J, Li Z, Brandis KJ, Bu J, Sun Z, Yu Q, Ramp D. Tracing geochemical pollutants in stream water and soil from mining activity in an alpine catchment. CHEMOSPHERE 2020; 242:125167. [PMID: 31678854 DOI: 10.1016/j.chemosphere.2019.125167] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 10/17/2019] [Accepted: 10/20/2019] [Indexed: 06/10/2023]
Abstract
This research developed a method of tracing major water chemical parameters (WCP) and soil heavy metals (HM) to identify the processes of mining pollution in topographically complex landscapes. Ninety-nine spatially distributed water samples were collected to characterise the hydrochemical characteristics of an alpine river in north-west China. Sixty river WCP and fifty-six soil HM samples from areas near mining sites were then used to analyse the mining pollution process. Geographical and mining activity characteristics were derived from topographic and mine site information. The occurrence of sulphates (SO42-) and nitrates (NO3-) in river water were highly correlated (up to 0.70), providing strong evidence of pollution from nearby mining activities. Levels of arsenic and cadmium were high in first and fifth order streams, where mining activities were most concentrated. The modelling results showed that geographical patterns and mining activity account for predicting HM distribution, and WCP can be reasonable predictors to trace soil mining pollution. This research can help improve the accuracy of predicting the mining pollution process.
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Affiliation(s)
- Jianguo Li
- Centre for Compassionate Conservation, Faculty of Science, University of Technology Sydney, Ultimo, 2007, NSW, Australia
| | - Zongxing Li
- Key Laboratory of Eco-hydrology of Inland River Basin, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China.
| | - Kate J Brandis
- Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, University of New South Wales, Kensington, 2052, NSW, Australia
| | - Jianwei Bu
- Laboratory of Basin Hydrology and Wetland Eco-restoration, China University of Geosciences, Wuhan, 430074, China
| | - Ziyong Sun
- Laboratory of Basin Hydrology and Wetland Eco-restoration, China University of Geosciences, Wuhan, 430074, China
| | - Qiang Yu
- School of Life Science, University of Technology Sydney, Ultimo, 2007, NSW, Australia
| | - Daniel Ramp
- Centre for Compassionate Conservation, Faculty of Science, University of Technology Sydney, Ultimo, 2007, NSW, Australia.
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Mukherjee A, Gupta S, Coomar P, Fryar AE, Guillot S, Verma S, Bhattacharya P, Bundschuh J, Charlet L. Plate tectonics influence on geogenic arsenic cycling: From primary sources to global groundwater enrichment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 683:793-807. [PMID: 31153003 DOI: 10.1016/j.scitotenv.2019.04.255] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 03/08/2019] [Accepted: 04/16/2019] [Indexed: 05/15/2023]
Abstract
More than 100 million people around the world are endangered by geogenic arsenic (As) in groundwater, residing in sedimentary aquifers. However, not all sedimentary aquifers are groundwater As enriched, and the ultimate source of As in enriched aquifer sediments is yet-unknown, globally. A reconnaissance of the major aquifers suggests that major As enriched aquifers are predictably systematic on a global scale, existing in sedimentary foreland basins in the vicinity of modern or ancient orogenic systems. In conformity with the Principle of Uniformitarianism, we demonstrate that the groundwater As comes from magmatic arcs (primary source) in present (e.g. Andes) or ancient (e.g. Himalaya) continental convergent margins of some of the most prominent orogenic systems across the globe, and ends up in sediments (secondary source) in adjoining foreland or related basins that eventually act as aquifers. These arc magmas scavenge As while rising through the deep continental crust. Erosion of such orogens ultimately increases the bulk As content in sediments of adjoining basins, leading to groundwater As enrichment in downstream aquifers. Such As-polluted aquifers are eventually extensively used for groundwater exploitation, for drinking and other human purposes. Surface geological and biogeochemical processes, like redox reactions, are conducive to such groundwater As enrichment. We suggest this model by integrating our study of long-time observations in Himalayan and Andean basin aquifers, and generalizing 63 major aquifers across the globe, to demonstrate the source-to-sink transport of As, thereby delineating it's geogenic cycling in the subsurface. This work outlines the specifics of the mechanisms that would drive the processes of groundwater As enrichment across spatio-temporal scales, i.e. tectonic-scale taking place over millions of years on continental-scale and groundwater pollution taking place at human time-scales on village to household scale. Thus, in this work, we demonstrate a direct evidence of connectivity between global geological processes and individual human health.
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Affiliation(s)
- Abhijit Mukherjee
- Department of Geology and Geophysics, School of Environmental Science and Engineering, Indian Institute of Technology (IIT), Kharagpur, West Bengal 721302, India.
| | - Saibal Gupta
- Department of Geology and Geophysics, School of Environmental Science and Engineering, Indian Institute of Technology (IIT), Kharagpur, West Bengal 721302, India
| | - Poulomee Coomar
- Department of Geology and Geophysics, School of Environmental Science and Engineering, Indian Institute of Technology (IIT), Kharagpur, West Bengal 721302, India
| | - Alan E Fryar
- Department of Earth and Environmental Sciences, University of Kentucky, Lexington, KY 40506-0053, USA
| | - Stephane Guillot
- Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, IRD, IFSTTAR, ISTerre, 38000 Grenoble, France
| | - Swati Verma
- Department of Geology and Geophysics, School of Environmental Science and Engineering, Indian Institute of Technology (IIT), Kharagpur, West Bengal 721302, India
| | - Prosun Bhattacharya
- KTH-International Groundwater Arsenic Research Group, Department of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology, Teknikringen 10B, SE-100 44 Stockholm
| | - Jochen Bundschuh
- School of Civil Engineering & Surveying & International Centre for Applied Climate Sciences, University of Southern Queensland (USQ), Toowoomba, QLD 4350, Australia
| | - Laurent Charlet
- Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, IRD, IFSTTAR, ISTerre, 38000 Grenoble, France
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Dallai L, Bianchini G, Avanzinelli R, Natali C, Conticelli S. Heavy oxygen recycled into the lithospheric mantle. Sci Rep 2019; 9:8793. [PMID: 31217538 PMCID: PMC6584624 DOI: 10.1038/s41598-019-45031-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 05/24/2019] [Indexed: 11/11/2022] Open
Abstract
Magmas in volcanic arcs have geochemical and isotopic signatures that can be related to mantle metasomatism due to fluids and melts released by the down-going oceanic crust and overlying sediments, which modify the chemistry and mineralogy of the mantle wedge. However, the effectiveness of subduction-related metasomatic processes is difficult to evaluate because the composition of arc magmas is often overprinted by interactions with crustal lithologies occurring during magma ascent and emplacement. Here, we show unequivocal evidence for recycling of continental crust components into the mantle. Veined peridotite xenoliths sampled from Tallante monogenetic volcanoes in the Betic Cordillera (southern Spain) provide insights for mantle domains that reacted with Si-rich melts derived by partial melting of subducted crustal material. Felsic veins crosscutting peridotite and the surrounding orthopyroxene-rich metasomatic aureoles show the highest 18O/16O ratios measured to date in upper mantle assemblages worldwide. The anomalously high oxygen isotope compositions, coupled with very high 87Sr/86Sr values, imply the continental crust origin of the injected melts. Isotopic anomalies are progressively attenuated in peridotite away from the veins, showing 18O isotope variations well correlated with the amount of newly formed orthopyroxene. Diffusion may also affect the isotope ratios of mantle rocks undergoing crustal metasomatism due to the relaxation of 18O isotope anomalies to normal mantle values through time. Overall, the data define an O isotope “benchmark” allowing discrimination between mantle sources that attained re-equilibration after metasomatism (>5 Myr) and those affected by more recent subduction-derived enrichment processes.
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Affiliation(s)
- Luigi Dallai
- Istituto di Geoscienze e Georisorse - Sede, CNR, Via G. Moruzzi, 1, I-56124, Pisa, Italy.
| | - Gianluca Bianchini
- Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara, Via G. Saragat, 1, I-44122, Ferrara, Italy
| | - Riccardo Avanzinelli
- Dipartimento di Scienze della Terra, Università degli Studi di Firenze, Via G. La Pira, 4, I-50121, Firenze, Italy. .,Istituto di Geoscienze e Georisorse - Sede Secondaria di Firenze, CNR, Via G. La Pira, 4, I-50121, Firenze, Italy.
| | - Claudio Natali
- Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara, Via G. Saragat, 1, I-44122, Ferrara, Italy.,Dipartimento di Scienze della Terra, Università degli Studi di Firenze, Via G. La Pira, 4, I-50121, Firenze, Italy
| | - Sandro Conticelli
- Dipartimento di Scienze della Terra, Università degli Studi di Firenze, Via G. La Pira, 4, I-50121, Firenze, Italy.,Istituto di Geoscienze e Georisorse - Sede Secondaria di Firenze, CNR, Via G. La Pira, 4, I-50121, Firenze, Italy.,Istituto di Geologia Ambientale e Geoingegneria, CNR, Area della Ricerca Roma 1 - Montelibretti, Via Salaria km 29,300, I-00015, Monterotondo, Roma, Italy
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8
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Origin of arc magmatic signature: A temperature-dependent process for trace element (re)-mobilization in subduction zones. Sci Rep 2019; 9:7098. [PMID: 31068627 PMCID: PMC6506526 DOI: 10.1038/s41598-019-43605-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 04/27/2019] [Indexed: 11/09/2022] Open
Abstract
Serpentinite is a major carrier of fluid-mobile elements in subduction zones, which influences the geochemical signature of arc magmatism (e.g. high abundances of Li, Ba, Sr, B, As, Mo and Pb). Based on results from Neoproterozoic serpentinites in the Arabian-Nubian Shield, we herein report the role of antigorite in the transportation of fluid-mobile elements (FME) and light rare earth elements (LREE) from the subducted slab to arc-related magma during subduction. The serpentinites contain two generations of antigorites: the older generation is coarse-grained, formed at a temperature range of 165-250 °C and is enriched in Li, Rb, Ba and Cs, whereas the younger generation is finer-grained, formed at higher temperature conditions (425-475 °C) and has high concentrations of B, As, Sb, Mo, Pb, Sr and LREE. Magnesite, on the other hand, remains stable at sub-arc depths beyond the stability field of both antigorites, and represents a potential reservoir of FME and LREE for deeper mantle melts. Magnesite has high FME and LREE absorbing capacity (over 50-60%) higher than serpentine phases. Temperature is the main controlling factor for stability of these minerals and therefore the release of these elements from subducted slabs into arc magmatism. As the liberation of these elements varies along the length of the slab, the resulting cross-arc geochemical variation trend can help to determine the subduction polarity of ancient arcs.
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9
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Aiuppa A, Fischer TP, Plank T, Bani P. CO 2 flux emissions from the Earth's most actively degassing volcanoes, 2005-2015. Sci Rep 2019; 9:5442. [PMID: 30931997 PMCID: PMC6443792 DOI: 10.1038/s41598-019-41901-y] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Accepted: 03/20/2019] [Indexed: 11/09/2022] Open
Abstract
The global carbon dioxide (CO2) flux from subaerial volcanoes remains poorly quantified, limiting our understanding of the deep carbon cycle during geologic time and in modern Earth. Past attempts to extrapolate the global volcanic CO2 flux have been biased by observations being available for a relatively small number of accessible volcanoes. Here, we propose that the strong, but yet unmeasured, CO2 emissions from several remote degassing volcanoes worldwide can be predicted using regional/global relationships between the CO2/ST ratio of volcanic gases and whole-rock trace element compositions (e.g., Ba/La). From these globally linked gas/rock compositions, we predict the CO2/ST gas ratio of 34 top-degassing remote volcanoes with no available gas measurements. By scaling to volcanic SO2 fluxes from a global catalogue, we estimate a cumulative “unmeasured” CO2 output of 11.4 ± 1.1 Mt/yr (or 0.26 ± 0.02·1012 mol/yr). In combination with the measured CO2 output of 27.4 ± 3.6 Mt/yr (or 0.62 ± 0.08·1012 mol/yr), our results constrain the time-averaged (2005–2015) cumulative CO2 flux from the Earth’s 91 most actively degassing subaerial volcanoes at 38.7 ± 2.9 Mt/yr (or 0.88 ± 0.06·1012 mol/yr).
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Affiliation(s)
| | - Tobias P Fischer
- Department of Earth and Planetary Sciences, New Mexico University, Albuquerque, USA
| | - Terry Plank
- Lamont-Doherty Earth Observatory, Columbia University, New York, USA
| | - Philipson Bani
- Laboratoire Magmas et Volcans, Université Blaise Pascal - CNRS -IRD, OPGC, Aubière, France
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10
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Abstract
Subduction zones impose an important control on the geochemical cycling between the surficial and internal reservoirs of the Earth. Sulphur and carbon are transferred into Earth’s mantle by subduction of pelagic sediments and altered oceanic lithosphere. Release of oxidizing sulphate- and carbonate-bearing fluids modifies the redox state of the mantle and the chemical budget of subduction zones. Yet, the mechanisms of sulphur and carbon cycling within subduction zones are still unclear, in part because data are typically derived from arc volcanoes where fluid compositions are modified during transport through the mantle wedge. We determined the bulk rock elemental, and sulphur and carbon isotope compositions of exhumed ultramafic and metabasic rocks from Syros, Greece. Comparison of isotopic data with major and trace element compositions indicates seawater alteration and chemical exchange with sediment-derived fluids within the subduction zone channel. We show that small bodies of detached slab material are subject to metasomatic processes during exhumation, in contrast to large sequences of obducted ophiolitic sections that retain their seafloor alteration signatures. In particular, fluids circulating along the plate interface can cause sulphur mobilization during several stages of exhumation within high-pressure rocks. This takes place more pervasively in serpentinites compared to mafic rocks.
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Abstract
AbstractThe strong resilience of the mineral zircon and its ability to host a wealth of isotopic information make it the best deep-time archive of Earth's continental crust. Zircon is found in most felsic igneous rocks, can be precisely dated and can fingerprint magmatic sources; thus, it has been widely used to document the formation and evolution of continental crust, from pluton- to global-scale. Here, we present a review of major contributions that zircon studies have made in terms of understanding key questions involving the formation of the continents. These include the conditions of continent formation on early Earth, the onset of plate tectonics and subduction, the rate of crustal growth through time and the governing balance of continental addition v. continental loss, and the role of preservation bias in the zircon record.Supplementary material:A compilation used in this study of previously published detrital zircon U-Pb-Hf isotope data are available at http://www.geolsoc.org.uk/SUP18791
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Affiliation(s)
- Nick M. W. Roberts
- NERC Isotope Geosciences Laboratory, British Geological Survey, Keyworth, Nottingham NG12 5GG, UK
| | - Christopher J. Spencer
- NERC Isotope Geosciences Laboratory, British Geological Survey, Keyworth, Nottingham NG12 5GG, UK
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12
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A 'hidden' 18O-enriched reservoir in the sub-arc mantle. Sci Rep 2014; 4:4232. [PMID: 24577190 PMCID: PMC3937801 DOI: 10.1038/srep04232] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 02/13/2014] [Indexed: 11/09/2022] Open
Abstract
Plate subduction continuously transports crustal materials with high-δ(18)O values down to the mantle wedge, where mantle peridotites are expected to achieve the high-δ(18)O features. Elevated δ(18)O values relative to the upper mantle value have been reported for magmas from some subduction zones. However, peridotites with δ(18)O values significantly higher than the well-defined upper mantle values have never been observed from modern subduction zones. Here we present in-situ oxygen isotope data of olivine crystals in Sailipu mantle xenoliths from South Tibet, which have been subjected to a long history of Tethyan subduction before the India-Asia collision. Our data identify for the first time a metasomatized mantle that, interpreted as the sub-arc lithospheric mantle, shows anomalously enriched oxygen isotopes (δ(18)O = +8.03 ± 0.28 ‰). Such a high-δ(18)O mantle commonly does not contribute significantly to typical island arc basalts. However, partial melting or contamination of such a high-δ(18)O mantle is feasible to account for the high-δ(18)O signatures in arc basalts.
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Kastner M, Solomon EA, Harris RN, Torres ME. Fluid Origins, Thermal Regimes, and Fluid and Solute Fluxes in the Forearc of Subduction Zones. EARTH AND LIFE PROCESSES DISCOVERED FROM SUBSEAFLOOR ENVIRONMENTS - A DECADE OF SCIENCE ACHIEVED BY THE INTEGRATED OCEAN DRILLING PROGRAM (IODP) 2014. [DOI: 10.1016/b978-0-444-62617-2.00022-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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14
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Effect of Sediments on Aqueous Silica Transport in Subduction Zones. ACTA ACUST UNITED AC 2013. [DOI: 10.1029/gm096p0277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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15
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Does Fracture Zone Subduction Increase Sediment Flux and Mantle Melting in Subduction Zones? Trace Element Evidence from Aleutian Arc Basalt. ACTA ACUST UNITED AC 2013. [DOI: 10.1029/gm096p0285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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16
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Boron and Other Fluid-mobile Elements in Volcanic Arc Lavas: Implications for Subduction Processes. ACTA ACUST UNITED AC 2013. [DOI: 10.1029/gm096p0269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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17
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Davidson JP. Deciphering Mantle and Crustal Signatures in Subduction Zone Magmatism. ACTA ACUST UNITED AC 2013. [DOI: 10.1029/gm096p0251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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Ryan J, Morris J, Bebout G, Leeman B. Describing Chemical Fluxes in Subduction Zones: Insights from “Depth-Profiling” Studies of Arc and Forearc Rocks. SUBDUCTION TOP TO BOTTOM 2013. [DOI: 10.1029/gm096p0263] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Staudigel H, Plank T, White B, Schmincke HU. Geochemical Fluxes During Seafloor Alteration of the Basaltic Upper Oceanic Crust: DSDP Sites 417 and 418. SUBDUCTION TOP TO BOTTOM 2013. [DOI: 10.1029/gm096p0019] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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20
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Abd El-Rahman Y, Helmy HM, Shibata T, Yoshikawa M, Arai S, Tamura A. Mineral chemistry of the Neoproterozoic Alaskan-type Akarem Intrusion with special emphasis on amphibole: Implications for the pluton origin and evolution of subduction-related magma. LITHOS 2012; 155:410-425. [DOI: 10.1016/j.lithos.2012.09.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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Separation of supercritical slab-fluids to form aqueous fluid and melt components in subduction zone magmatism. Proc Natl Acad Sci U S A 2012; 109:18695-700. [PMID: 23112158 DOI: 10.1073/pnas.1207687109] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Subduction-zone magmatism is triggered by the addition of H(2)O-rich slab-derived components: aqueous fluid, hydrous partial melts, or supercritical fluids from the subducting slab. Geochemical analyses of island arc basalts suggest two slab-derived signatures of a melt and a fluid. These two liquids unite to a supercritical fluid under pressure and temperature conditions beyond a critical endpoint. We ascertain critical endpoints between aqueous fluids and sediment or high-Mg andesite (HMA) melts located, respectively, at 83-km and 92-km depths by using an in situ observation technique. These depths are within the mantle wedge underlying volcanic fronts, which are formed 90 to 200 km above subducting slabs. These data suggest that sediment-derived supercritical fluids, which are fed to the mantle wedge from the subducting slab, react with mantle peridotite to form HMA supercritical fluids. Such HMA supercritical fluids separate into aqueous fluids and HMA melts at 92 km depth during ascent. The aqueous fluids are fluxed into the asthenospheric mantle to form arc basalts, which are locally associated with HMAs in hot subduction zones. The separated HMA melts retain their composition in limited equilibrium with the surrounding mantle. Alternatively, they equilibrate with the surrounding mantle and change the major element chemistry to basaltic composition. However, trace element signatures of sediment-derived supercritical fluids remain more in the melt-derived magma than in the fluid-induced magma, which inherits only fluid-mobile elements from the sediment-derived supercritical fluids. Separation of slab-derived supercritical fluids into melts and aqueous fluids can elucidate the two slab-derived components observed in subduction zone magma chemistry.
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22
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Ozawa K, Shimizu N. Open-system melting in the upper mantle: Constraints from the Hayachine-Miyamori ophiolite, northeastern Japan. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/95jb01967] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Grove TL, Till CB, Lev E, Chatterjee N, Médard E. Kinematic variables and water transport control the formation and location of arc volcanoes. Nature 2009; 459:694-7. [PMID: 19494913 DOI: 10.1038/nature08044] [Citation(s) in RCA: 151] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Accepted: 04/06/2009] [Indexed: 11/09/2022]
Abstract
The processes that give rise to arc magmas at convergent plate margins have long been a subject of scientific research and debate. A consensus has developed that the mantle wedge overlying the subducting slab and fluids and/or melts from the subducting slab itself are involved in the melting process. However, the role of kinematic variables such as slab dip and convergence rate in the formation of arc magmas is still unclear. The depth to the top of the subducting slab beneath volcanic arcs, usually approximately 110 +/- 20 km, was previously thought to be constant among arcs. Recent studies revealed that the depth of intermediate-depth earthquakes underneath volcanic arcs, presumably marking the slab-wedge interface, varies systematically between approximately 60 and 173 km and correlates with slab dip and convergence rate. Water-rich magmas (over 4-6 wt% H(2)O) are found in subduction zones with very different subduction parameters, including those with a shallow-dipping slab (north Japan), or steeply dipping slab (Marianas). Here we propose a simple model to address how kinematic parameters of plate subduction relate to the location of mantle melting at subduction zones. We demonstrate that the location of arc volcanoes is controlled by a combination of conditions: melting in the wedge is induced at the overlap of regions in the wedge that are hotter than the melting curve (solidus) of vapour-saturated peridotite and regions where hydrous minerals both in the wedge and in the subducting slab break down. These two limits for melt generation, when combined with the kinematic parameters of slab dip and convergence rate, provide independent constraints on the thermal structure of the wedge and accurately predict the location of mantle wedge melting and the position of arc volcanoes.
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Affiliation(s)
- T L Grove
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
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Phase transition in the subducted oceanic lithosphere and generation of the subduction zone magma. CHINESE SCIENCE BULLETIN 2008. [DOI: 10.1007/s11434-008-0405-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Chavagnac V, German CR, Taylor RN. Global environmental effects of large volcanic eruptions on ocean chemistry: Evidence from “hydrothermal” sediments (ODP Leg 185, Site 1149B). ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007jb005333] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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26
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Savov IP, Ryan JG, D'Antonio M, Fryer P. Shallow slab fluid release across and along the Mariana arc-basin system: Insights from geochemistry of serpentinized peridotites from the Mariana fore arc. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jb004749] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Cagnioncle AM, Parmentier EM, Elkins-Tanton LT. Effect of solid flow above a subducting slab on water distribution and melting at convergent plate boundaries. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2007jb004934] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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28
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Singer BS, Jicha BR, Leeman WP, Rogers NW, Thirlwall MF, Ryan J, Nicolaysen KE. Along-strike trace element and isotopic variation in Aleutian Island arc basalt: Subduction melts sediments and dehydrates serpentine. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jb004897] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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29
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Walker JA, Mickelson JE, Thomas RB, Patino LC, Cameron B, Carr MJ, Feigenson MD, Edwards RL. U-series disequilibria in Guatemalan lavas, crustal contamination, and implications for magma genesis along the Central American subduction zone. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jb004589] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Kelley KA, Plank T, Grove TL, Stolper EM, Newman S, Hauri E. Mantle melting as a function of water content beneath back-arc basins. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2005jb003732] [Citation(s) in RCA: 205] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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31
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Arculus RJ. Evolution of arc magmas and their volatiles. GEOPHYSICAL MONOGRAPH SERIES 2004. [DOI: 10.1029/150gm09] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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32
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George R, Turner S, Hawkesworth C, Morris J, Nye C, Ryan J, Zheng SH. Melting processes and fluid and sediment transport rates along the Alaska-Aleutian arc from an integrated U-Th-Ra-Be isotope study. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2002jb001916] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Rhiannon George
- Department of Earth Sciences; University of Bristol; Bristol UK
| | - Simon Turner
- Department of Earth Sciences; University of Bristol; Bristol UK
| | | | - Julie Morris
- Department of Earth and Planetary Sciences; Washington University; Saint Louis Missouri USA
| | - Chris Nye
- Alaska Volcano Observatory; Alaska Division of Geological and Geophysical Surveys; Fairbanks Alaska USA
| | - Jeff Ryan
- Department of Geology; University of South Florida-Tampa; Tampa Florida USA
| | - Shu-Hui Zheng
- Department of Earth System Science; University of California; Irvine California USA
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33
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Niu Y, O'Hara MJ. Origin of ocean island basalts: A new perspective from petrology, geochemistry, and mineral physics considerations. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2002jb002048] [Citation(s) in RCA: 250] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Yaoling Niu
- Department of Earth Sciences; Cardiff University; Cardiff UK
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34
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Carr MJ, Feigenson MD, Patino LC, Walker JA. Volcanism and geochemistry in Central America: Progress and problems. INSIDE THE SUBDUCTION FACTORY 2003. [DOI: 10.1029/138gm09] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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Kelemen PB, Rilling JL, Parmentier EM, Mehl L, Hacker BR. Thermal structure due to solid-state flow in the mantle wedge beneath arcs. INSIDE THE SUBDUCTION FACTORY 2003. [DOI: 10.1029/138gm13] [Citation(s) in RCA: 133] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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36
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Kelemen PB, Yogodzinski GM, Scholl DW. Along-strike variation in the Aleutian Island Arc: Genesis of high Mg# andesite and implications for continental crust. INSIDE THE SUBDUCTION FACTORY 2003. [DOI: 10.1029/138gm11] [Citation(s) in RCA: 176] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
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Gaetani GA, Grove TL. Experimental constraints on melt generation in the mantle wedge. INSIDE THE SUBDUCTION FACTORY 2003. [DOI: 10.1029/138gm07] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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39
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Tatsumi Y, Kogiso T. The subduction factory: its role in the evolution of the Earth’s crust and mantle. ACTA ACUST UNITED AC 2003. [DOI: 10.1144/gsl.sp.2003.219.01.03] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractSubduction zones are major sites of magmatism on the Earth. Dehydration processes and associated element transport, which take place in both the subducting lithosphere and the down-dragged hydrated peridotite layer at the base of the mantle wedge, are largely responsible for the following characteristics common to most subduction zones: (1) the presence of dual volcanic chains within a single volcanic arc; (2) the negative correlation between the volcanic arc width and the subduction angle; (3) selective enrichment of particular incompatible trace elements; and (4) systematic across-arc variations in incompatible trace element concentrations. The occurrence of two types of andesites, calcalkalic and tholeiitic, typifies magmatism in subduction zones. Examination of geochemical characteristics of those andesites in the NE Japan arc and bulk continental crust reveals marked compositional similarity between calc-alkalic andesites and continental crust. One of the principal mechanisms of generation of calc-alkalic andesites, at least those on the NE Japan arc, is the mixing of two magmas, having basaltic and felsic compositions and being derived from partial melting of the mantle and the overriding basaltic crust, respectively. It may be thus suggested that this process would also have contributed greatly to continental crust formation. If this is the case, then the melting residue after extraction of felsic melts should be removed and delaminated from the initial crust into the mantle in order to form ‘andesitic’ crust compositions. These processes cause accumulation in the deep mantle of residual materials, such as delaminated crust materials and dehydrated, compositionally modified subducted oceanic crusts and sediments. Geochemical modelling suggests that such residual components have evolved to form enriched mantle reservoirs.
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Affiliation(s)
- Yoshiyuki Tatsumi
- Institute for Frontier Research on Earth Evolution (IFREE), Japan Marine Science and Technology Center (JAMSTEC)
Yokosuka 237-0061, Japan
| | - Tetsu Kogiso
- Institute for Frontier Research on Earth Evolution (IFREE), Japan Marine Science and Technology Center (JAMSTEC)
Yokosuka 237-0061, Japan
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40
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Peacock SM. Thermal structure and metamorphic evolution of subducting slabs. INSIDE THE SUBDUCTION FACTORY 2003. [DOI: 10.1029/138gm02] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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Fischer TP, Hilton DR, Zimmer MM, Shaw AM, Sharp ZD, Walker JA. Subduction and recycling of nitrogen along the Central American margin. Science 2002; 297:1154-7. [PMID: 12183622 DOI: 10.1126/science.1073995] [Citation(s) in RCA: 158] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We report N and He isotopic and relative abundance characteristics of volatiles emitted from two segments of the Central American volcanic arc. In Guatemala, delta15N values are positive (i.e., greater than air) and N2/He ratios are high (up to 25,000). In contrast, Costa Rican N2/He ratios are low (maximum 1483) and delta15N values are negative (minimum -3.0 per mil). The results identify shallow hemipelagic sediments, subducted into the Guatemalan mantle, as the transport medium for the heavy N. Mass balance arguments indicate that the subducted N is efficiently cycled to the atmosphere by arc volcanism. Therefore, the subduction zone acts as a "barrier" to input of sedimentary N to the deeper mantle.
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Affiliation(s)
- Tobias P Fischer
- Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, NM 87131, USA.
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42
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Lizarralde D. Crustal construction of a volcanic arc, wide-angle seismic results from the western Alaska Peninsula. ACTA ACUST UNITED AC 2002. [DOI: 10.1029/2001jb000230] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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43
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Sun CH, Stern RJ. Genesis of Mariana shoshonites: Contribution of the subduction component. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2000jb900342] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Walker JA, Patino LC, Cameron BI, Carr MJ. Petrogenetic insights provided by compositional transects across the Central American arc: Southeastern Guatemala and Honduras. ACTA ACUST UNITED AC 2000. [DOI: 10.1029/2000jb900173] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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45
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Coler DG, Wortman GL, Samson SD, Hibbard JP, Stern R. U-Pb Geochronologic, Nd Isotopic, and Geochemical Evidence for the Correlation of the Chopawamsic and Milton Terranes, Piedmont Zone, Southern Appalachian Orogen. THE JOURNAL OF GEOLOGY 2000; 108:363-380. [PMID: 10856010 DOI: 10.1086/314411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/1999] [Accepted: 03/03/2000] [Indexed: 05/23/2023]
Abstract
We report U-Pb crystallization ages from four metavolcanic rocks and two granitic gneiss samples as well as whole-rock chemical analyses and Sm-Nd isotopic ratios from 25 metaigneous and metasedimentary rocks from the Chopawamsic and Milton terranes, southern Appalachian Orogen. A metarhyolite sample from the Chopawamsic Formation and a metabasalt sample from the Ta River Formation in the Chopawamsic terrane have indistinguishable U-Pb crystallization ages of 471.4+/-1.3 Ma and 470.0+1.3/-1.5 Ma, respectively. A sample from the Prospect granite that intruded metavolcanic rocks of the Ta River Formation yields a younger U-Pb date of 458.0+/-1 Ma. Metarhyolite and granitic gneiss samples from the northern part of the Milton terrane yield U-Pb dates of 458.5+3.8/-1.0 Ma and 450+/-1.8 Ma, respectively. Metavolcanic and metaplutonic rocks from both terranes span a range in major element composition from basalt to rhyolite. Trace element concentrations in these samples show enrichment in large-ion lithophile elements K, Ba, and Rb and depletion in high field strength elements Ti and Nb, similar to those from island arc volcanic rocks. Initial epsilon(Nd) values and T(DM) ages of the metaigneous and metasedimentary samples range from 0.2 to -7.2 and from 1200 to 1700 Ma for the Chopawamsic terrane and from 3.7 to -7.2 and from 850 to 1650 Ma for the Milton terrane. The crystallization ages for the metavolcanic and metaplutonic samples from both terranes indicate that Ordovician magmatism occurred in both. Similar epsilon(Nd) values from representative samples from both terranes suggest that both were generated from an isotopically similar source. Xenocrystic zircons from metavolcanic rocks in the Chopawamsic terrane have predominately Mesoproterozoic (207)Pb/(206)Pb ages (600-1300 Ma), but a single Archean (2.56 Ga) core was also present. The xenocrystic zircons and the generally negative epsilon(Nd) values indicate that both terranes are composed of isotopically evolved continental crust.
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Hochstaedter AG, Gill JB, Taylor B, Ishizuka O, Yuasa M, Monta S. Across-arc geochemical trends in the Izu-Bonin arc: Constraints on source composition and mantle melting. ACTA ACUST UNITED AC 2000. [DOI: 10.1029/1999jb900125] [Citation(s) in RCA: 117] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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47
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Affiliation(s)
- P. G. Burnard
- Division of Geological and
Planetary Sciences
Caltech
Pasadena, CA 91125, USA
E-mail:
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48
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Sturm ME, Klein EM, Graham DW, Karsten J. Age constraints on crustal recycling to the mantle beneath the southern Chile Ridge: He-Pb-Sr-Nd isotope systematics. ACTA ACUST UNITED AC 1999. [DOI: 10.1029/1998jb900107] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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49
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Hickey-Vargas R. Origin of the Indian Ocean-type isotopic signature in basalts from Philippine Sea plate spreading centers: An assessment of local versus large-scale processes. ACTA ACUST UNITED AC 1998. [DOI: 10.1029/98jb02052] [Citation(s) in RCA: 151] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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50
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Turner S, Hawkesworth C. Constraints on flux rates and mantle dynamics beneath island arcs from Tonga–Kermadec lava geochemistry. Nature 1997. [DOI: 10.1038/39257] [Citation(s) in RCA: 143] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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