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Статті в журналах з теми "Sub arc mantle"

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Автор: Grafiati

Опубліковано: 10 грудня 2022

Оновлено: 28 січня 2023

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1

Hall, Paul S., Lauren B. Cooper, and Terry Plank. "Thermochemical evolution of the sub-arc mantle due to back-arc spreading." Journal of Geophysical Research: Solid Earth 117, B2 (February 2012): n/a. http://dx.doi.org/10.1029/2011jb008507.

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2

FUKUDA, SATORU, SHUN'ICHI NAKAI, KENJI NIIHORI, MASASHI TSUKUI, SETSUYA NAKADA, TOSHITSUGU FUJII, and KENICHIRO TANI. "238U-230Th radioactive disequilibrium in the northern Izu arc: (230Th/232Th) in the sub-arc mantle." GEOCHEMICAL JOURNAL 42, no. 6 (2008): 461–79. http://dx.doi.org/10.2343/geochemj.42.461.

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3

Schiano, P., R. Clocchiatti, N. Shimizu, R. C. Maury, K. P. Jochum, and A. W. Hofmann. "Hydrous, silica-rich melts in the sub-arc mantle and their relationship with erupted arc lavas." Nature 377, no. 6550 (October 1995): 595–600. http://dx.doi.org/10.1038/377595a0.

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4

Eiler, John M., Brent McInnes, John W. Valley, Colin M. Graham, and Edward M. Stolper. "Oxygen isotope evidence for slab-derived fluids in the sub-arc mantle." Nature 393, no. 6687 (June 1998): 777–81. http://dx.doi.org/10.1038/31679.

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5

Dorendorf, Frank, Uwe Wiechert, and Gerhard Wörner. "Hydrated sub-arc mantle: a source for the Kluchevskoy volcano, Kamchatka/Russia." Earth and Planetary Science Letters 175, no. 1-2 (January 2000): 69–86. http://dx.doi.org/10.1016/s0012-821x(99)00288-5.

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6

Caulfield, J. T., S. P. Turner, A. Dosseto, N. J. Pearson, and C. Beier. "Source depletion and extent of melting in the Tongan sub-arc mantle." Earth and Planetary Science Letters 273, no. 3-4 (September 2008): 279–88. http://dx.doi.org/10.1016/j.epsl.2008.06.040.

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7

Kepezhinskas, Pavel, Marc J. Defant, and Elisabeth Widom. "Abundance and distribution of PGE and Au in the island-arc mantle: implications for sub-arc metasomatism." Lithos 60, no. 3-4 (February 2002): 113–28. http://dx.doi.org/10.1016/s0024-4937(01)00073-1.

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8

ARAI, Shoji, Hisatoshi HIRAI, and Kozo UTO. "Mantle peridotite xenoliths from the Southwest Japan arc. A model for the sub-arc upper mantle structure and composition of the Western Pacific rim." Journal of Mineralogical and Petrological Sciences 95, no. 4 (2000): 9–23. http://dx.doi.org/10.2465/jmps.95.9.

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9

Le Roux, Véronique, and Yan Liang. "Ophiolitic Pyroxenites Record Boninite Percolation in Subduction Zone Mantle." Minerals 9, no. 9 (September 18, 2019): 565. http://dx.doi.org/10.3390/min9090565.

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Анотація:

The peridotite section of supra-subduction zone ophiolites is often crosscut by pyroxenite veins, reflecting the variety of melts that percolate through the mantle wedge, react, and eventually crystallize in the shallow lithospheric mantle. Understanding the nature of parental melts and the timing of formation of these pyroxenites provides unique constraints on melt infiltration processes that may occur in active subduction zones. This study deciphers the processes of orthopyroxenite and clinopyroxenite formation in the Josephine ophiolite (USA), using new trace and major element analyses of pyroxenite minerals, closure temperatures, elemental profiles, diffusion modeling, and equilibrium melt calculations. We show that multiple melt percolation events are required to explain the variable chemistry of peridotite-hosted pyroxenite veins, consistent with previous observations in the xenolith record. We argue that the Josephine ophiolite evolved in conditions intermediate between back-arc and sub-arc. Clinopyroxenites formed at an early stage of ophiolite formation from percolation of high-Ca boninites. Several million years later, and shortly before exhumation, orthopyroxenites formed through remelting of the Josephine harzburgites through percolation of ultra-depleted low-Ca boninites. Thus, we support the hypothesis that multiple types of boninites can be created at different stages of arc formation and that ophiolitic pyroxenites uniquely record the timing of boninite percolation in subduction zone mantle.

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10

Maury, René C., Marc J. Defant, and Jean-Louis Joron. "Metasomatism of the sub-arc mantle inferred from trace elements in Philippine xenoliths." Nature 360, no. 6405 (December 1992): 661–63. http://dx.doi.org/10.1038/360661a0.

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11

Zhang, Yunying, Chao Yuan, Min Sun, Xiaoping Long, Zongying Huang, Yingde Jiang, Pengfei Li, and Long Du. "Two late Carboniferous belts of Nb-enriched mafic magmatism in the Eastern Tianshan: Heterogeneous mantle sources and geodynamic implications." GSA Bulletin 132, no. 9-10 (January 7, 2020): 1863–80. http://dx.doi.org/10.1130/b35366.1.

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Abstract Identification of subduction to post-collisional tectonic transitions is critical to the study of orogenic belts. To characterize such a transition in the Tianshan Orogenic Belt, a systematic study was conducted on the late Carboniferous (305–301 Ma) Hongshankou dolerite and Dikan’er basalt of Eastern Tianshan. The Hongshankou dolerites have relatively high Ti and Nb contents, akin to Nb-enriched arc basalts. Based on the Nb/La ratios, these dolerites can be divided into low-Nb/La (0.35–0.40) and high-Nb/La (0.67–1.4) groups, which were likely derived respectively from slab melt-metasomatized mantle wedge and a mixed mantle source involving depleted super-slab and enriched sub-slab asthenospheric components. Like the low-Nb/La dolerites, the Dikan’er basalts possess low Nb/La (0.42–0.46) ratios, suggesting a mantle source previously modified by slab components. In addition, the Dikan’er basalts have variable Nb contents and can be grouped into normal arc basalts and Nb-rich basalts that can be attributed to a common mantle source with different degrees of mantle melting, as demonstrated by the positive correlations of La/Sm with La and Nb. By integrating available data, two late Carboniferous belts of Nb-enriched mafic magmatism are recognized in the Eastern Tianshan, with one in the Yamansu arc (336–301 Ma) and the other in the Bogda Mountains (305–301 Ma). The former is characterized by low Nb/La (<0.6) ratios, reflecting derivation from mantle metasomatized by slab-derived melt during a subduction process; the latter exhibits an abrupt Nb/La increase from 0.6 to 1.4, indicating significant input of sub-slab asthenospheric mantle that was probably induced by slab break off. Accordingly, we propose that the tectonic transition from subduction to post-collision in the Eastern Tianshan occurred in the latest Carboniferous (305–301 Ma) and was marked by the abrupt input of deep and enriched asthenospheric mantle.

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12

Neumann, Else-Ragnhild, and Nina S. C. Simon. "Ultra-refractory mantle xenoliths from ocean islands: How do they compare to peridotites retrieved from oceanic sub-arc mantle?" Lithos 107, no. 1-2 (January 2009): 1–16. http://dx.doi.org/10.1016/j.lithos.2008.06.003.

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13

Czertowicz, T. A., J. M. Scott, T. E. Waight, J. M. Palin, Q. H. A. Van der Meer, P. Le Roux, C. Münker, and S. Piazolo. "The Anita Peridotite, New Zealand: Ultra-depletion and Subtle Enrichment in Sub-arc Mantle." Journal of Petrology 57, no. 4 (February 20, 2016): 717–50. http://dx.doi.org/10.1093/petrology/egw001.

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14

Cvetković, Vladica, Hilary Downes, Dejan Prelević, Marina Lazarov, and Kristina Resimić-Šarić. "Geodynamic significance of ultramafic xenoliths from Eastern Serbia: Relics of sub-arc oceanic mantle?" Journal of Geodynamics 43, no. 4-5 (May 2007): 504–27. http://dx.doi.org/10.1016/j.jog.2006.11.003.

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15

Fischer, Tobias P., and Bernard Marty. "Volatile abundances in the sub-arc mantle: insights from volcanic and hydrothermal gas discharges." Journal of Volcanology and Geothermal Research 140, no. 1-3 (January 2005): 205–16. http://dx.doi.org/10.1016/j.jvolgeores.2004.07.022.

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16

Xiong, X. L., B. Xia, J. F. Xu, H. C. Niu, and W. S. Xiao. "Na depletion in modern adakites via melt/rock reaction within the sub-arc mantle." Chemical Geology 229, no. 4 (May 2006): 273–92. http://dx.doi.org/10.1016/j.chemgeo.2005.11.008.

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17

McInnes, Brent I. A., Michel Gregoire, Raymond A. Binns, Peter M. Herzig, and Mark D. Hannington. "Hydrous metasomatism of oceanic sub-arc mantle, Lihir, Papua New Guinea: petrology and geochemistry of fluid-metasomatised mantle wedge xenoliths." Earth and Planetary Science Letters 188, no. 1-2 (May 2001): 169–83. http://dx.doi.org/10.1016/s0012-821x(01)00306-5.

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18

Bénard, Antoine, Alan B. Woodland, Richard J. Arculus, Oliver Nebel, and Sarlae R. B. McAlpine. "Variation in sub-arc mantle oxygen fugacity during partial melting recorded in refractory peridotite xenoliths from the West Bismarck Arc." Chemical Geology 486 (May 2018): 16–30. http://dx.doi.org/10.1016/j.chemgeo.2018.03.004.

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19

McNamara, Daniel E., and Michael E. Pasyanos. "Seismological evidence for a sub-volcanic arc mantle wedge beneath the Denali volcanic gap, Alaska." Geophysical Research Letters 29, no. 16 (August 15, 2002): 61–1. http://dx.doi.org/10.1029/2001gl014088.

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20

Peslier, Anne H., James F. Luhr, and Jeffrey Post. "Low water contents in pyroxenes from spinel-peridotites of the oxidized, sub-arc mantle wedge." Earth and Planetary Science Letters 201, no. 1 (July 2002): 69–86. http://dx.doi.org/10.1016/s0012-821x(02)00663-5.

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21

Su, Ben-Xun, Fang-Zhen Teng, Yan Hu, Ren-Deng Shi, Mei-Fu Zhou, Bin Zhu, Fan Liu, et al. "Iron and magnesium isotope fractionation in oceanic lithosphere and sub-arc mantle: Perspectives from ophiolites." Earth and Planetary Science Letters 430 (November 2015): 523–32. http://dx.doi.org/10.1016/j.epsl.2015.08.020.

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22

Jagoutz, Oliver, Pierre Bouilhol, Urs Schaltegger, and Othmar Müntener. "The isotopic evolution of the Kohistan Ladakh arc from subduction initiation to continent arc collision." Geological Society, London, Special Publications 483, no. 1 (September 19, 2018): 165–82. http://dx.doi.org/10.1144/sp483.7.

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Анотація:

AbstractMagmatic arcs associated with subduction zones are the dominant active locus of continental crust formation, and evolve in space and time towards magmatic compositions comparable to that of continental crust. Accordingly, the secular evolution of magmatic arcs is crucial to the understanding of crust formation processes. In this paper we present the first comprehensive U–Pb, Hf, Nd and Sr isotopic dataset documenting c. 120 myr of magmatic evolution in the Kohistan-Ladakh paleo-island arc. We found a long-term magmatic evolution that is controlled by the overall geodynamic of the Neo-Tethys realm. Apart from the post-collisionnal melts, the intra-oceanic history of the arc shows two main episodes (150–80 Ma and 80–50 Ma) of distinct geochemical signatures involving the slab and the sub-arc mantle components that are intimately linked to the slab dynamics.

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23

Ishimaru, Satoko, Yuji Saikawa, Makoto Miura, Osman Parlak, and Shoji Arai. "Decoding of Mantle Processes in the Mersin Ophiolite, Turkey, of End-Member Arc Type: Location of the Boninite Magma Generation." Minerals 8, no. 10 (October 18, 2018): 464. http://dx.doi.org/10.3390/min8100464.

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The Mersin ophiolite, Turkey, is of typical arc type based on geochemistry of crustal rocks without any signs of mid-ocean ridge (MOR) affinity. We examined its ultramafic rocks to reveal sub-arc mantle processes. Mantle peridotites, poor in clinopyroxene (<1.0 vol.%), show high Fo content of olivine (90–92) and Cr# [=Cr/(Cr + Al) atomic ratio] (=0.62–0.77) of chromian spinel. NiO content of olivine is occasionally high (up to 0.5 wt.%) in the harzburgite. Moho-transition zone (MTZ) dunite is also highly depleted, i.e., spinel is high Cr# (0.78–0.89), clinopyroxene is poor in HREE, and olivine is high Fo (up to 92), but relatively low in NiO (0.1–0.4 wt.%). The harzburgite is residue after high-degree mantle melting, possibly assisted by slab-derived fluid. The high-Ni character of olivine suggests secondary metasomatic formation of olivine-replacing orthopyroxene although replacement textures are unclear. The MTZ dunite is of replacive origin, resulted from interaction between Mg-rich melt released from harzburgite diapir and another harzburgite at the diapir roof. The MTZ dunite is the very place that produced the boninitic and replacive dunite. The MTZ is thicker (>1 km) in Mersin than in MOR-related ophiolite (mostly < 500 m), and this is one of the features of arc-type ophiolite.

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24

Sandeman, H. A., B. L. Cousens, and C. J. Hemmingway. "Continental tholeiitic mafic rocks of the Paleoproterozoic Hurwitz Group, Central Hearne sub-domain, Nunavut: insight into the evolution of the Hearne sub-continental lithosphere." Canadian Journal of Earth Sciences 40, no. 9 (September 1, 2003): 1219–37. http://dx.doi.org/10.1139/e03-035.

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The Paleoproterozoic Hurwitz Group of the western Churchill Province is an erosional remnant of an areally extensive, predominantly shallow-water intracratonic basin comprised of four major sequences. Sequence 2, forming the central part of the stratigraphy, contains the Ameto Formation, a sequence of pillowed and massive basaltic rocks and associated gabbro sills termed the Happotiyik Member that are interlayered with subordinate deep-water mudstones, siltstones, and diamictites. Whole-rock geochemical data for the mafic rocks reveals a suite of homogeneous tholeiitic basalts with affinities to both continental and volcanic-arc tholeiites. Compatible trace elements and large-ion lithophile elements exhibit scattered behavior, whereas all high field strength elements show a systematic increase with Zr. The rocks are large-ion lithophile and light rare-earth element enriched, and have parallel primitive mantle normalized extended trace element patterns with prominent negative Nb, Ta, and Ti anomalies. εNd(t=2200 Ma) values for the rocks range from 0.0 to +0.8. The data indicate that the parental magmas were derived from a heterogeneous, predominantly depleted mantle source that included a minor metasomatically enriched component. Contamination by Neoarchean, juvenile silicic upper crust during ascent was minimal. We envisage that the rocks of the Happotiyik Member were generated from sub-continental lithospheric mantle that was stabilized immediately after formation of the ca. 2680 Ma, Neoarchean Central Hearne sub-domain. This enrichment occurred via metasomatic infiltration of subduction-derived fluids and melts into the overlying lithosphere. A wide range of Paleoproterozoic intra-continental mafic rocks in the western Churchill Province exhibit comparable geochemical and isotopic signatures that suggest an origin in the lithospheric mantle. These observations imply that the Hearne sub-continental lithospheric mantle has endured since the Neoarchean and likely persists today.

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25

Ishimaru, Satoko, and Shoji Arai. "Highly silicic glasses in peridotite xenoliths from Avacha volcano, Kamchatka arc; implications for melting and metasomatism within the sub-arc mantle." Lithos 107, no. 1-2 (January 2009): 93–106. http://dx.doi.org/10.1016/j.lithos.2008.07.005.

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26

Kimura, Takafumi, Kazuhito Ozawa, Takeshi Kuritani, Tsuyoshi Iizuka, and Mitsuhiro Nakagawa. "Thermal state of the upper mantle and the origin of the Cambrian-Ordovician ophiolite pulse: Constraints from ultramafic dikes of the Hayachine-Miyamori ophiolite." American Mineralogist 105, no. 12 (December 1, 2020): 1778–801. http://dx.doi.org/10.2138/am-2020-7160.

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Анотація:

Abstract Ophiolite pulses, which are periods of enhanced ophiolite generation and emplacement, are thought to have a relevance to highly active superplumes (superplume model). However, the Cambrian-Ordovician pulse has two critical geological features that cannot be explained by such a superplume model: predominance of subduction-related ophiolites and scarcity of plume-related magma activities. We addressed this issue by estimating the mechanism and condition of magma generation, including mantle potential temperature (MPT), from a ~500 Ma subduction-related ophiolite, the Hayachine-Miyamori ophiolite. We developed a novel method to overcome difficulties in global MPT estimation from an arc environment by using porphyritic ultramafic dikes showing flow differentiation, which have records of the chemical composition of the primitive magma, including its water content, because of their high pressure (~0.6 GPa) intrusion and rapid solidification. The solidus conditions for the primary magmas are estimated to be ~1450 °C, ~5.3 GPa. Geochemical data of the dikes show passive upwelling of a depleted mantle source in the garnet stability field without a strong influence of slab-derived fluids. These results, combined with the extensive fluxed melting of the mantle wedge prior to the dike formation, indicate sudden changes of the melting environment, its mechanism, and the mantle source from extensive fluxed melting of the mantle wedge to decompressional melting of the sub-slab mantle, which has been most plausibly triggered by a slab breakoff. The estimated MPT of the sub-slab mantle is ~1350 °C, which is very close to that of the current upper mantle and may reflect the global value of the upper mantle at ~500 Ma if small-scale convection maintained the shallow sub-slab mantle at a steady thermal state. We, therefore, conclude that the Cambrian-Ordovician ophiolite pulse is not attributable to the high temperature of the upper mantle. Frequent occurrence of slab breakoff, which is suggested by our geochemical compilation of Cambrian-Ordovician ophiolites, and subduction termination, which is probably related to the assembly of the Gondwana supercontinent, may be responsible for the ophiolite pulse.

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27

Czertowicz, T. A., V. G. Toy, and J. M. Scott. "Recrystallisation, phase mixing and strain localisation in peridotite during rapid extrusion of sub-arc mantle lithosphere." Journal of Structural Geology 88 (July 2016): 1–19. http://dx.doi.org/10.1016/j.jsg.2016.04.011.

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28

Khedr, Mohamed Zaki, and Shoji Arai. "Peridotite-chromitite complexes in the Eastern Desert of Egypt: Insight into Neoproterozoic sub-arc mantle processes." Gondwana Research 52 (December 2017): 59–79. http://dx.doi.org/10.1016/j.gr.2017.09.001.

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29

Wang, Jian, Kéiko H. Hattori, Rolf Kilian, and Charles R. Stern. "Metasomatism of sub-arc mantle peridotites below southernmost South America: reduction of fO2 by slab-melt." Contributions to Mineralogy and Petrology 153, no. 5 (December 23, 2006): 607–24. http://dx.doi.org/10.1007/s00410-006-0166-4.

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30

Halama, Ralf, Ivan P. Savov, Roberta L. Rudnick, and William F. McDonough. "Insights into Li and Li isotope cycling and sub-arc metasomatism from veined mantle xenoliths, Kamchatka." Contributions to Mineralogy and Petrology 158, no. 2 (January 30, 2009): 197–222. http://dx.doi.org/10.1007/s00410-009-0378-5.

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31

McInnes, Brent I. A., and Eion M. Cameron. "Carbonated, alkaline hybridizing melts from a sub-arc environment: Mantle wedge samples from the Tabar-Lihir-Tanga-Feni arc, Papua New Guinea." Earth and Planetary Science Letters 122, no. 1-2 (March 1994): 125–41. http://dx.doi.org/10.1016/0012-821x(94)90055-8.

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32

Dusel-Bacon, Cynthia, Warren C. Day, and John N. Aleinikoff. "Geochemistry, petrography, and zircon U–Pb geochronology of Paleozoic metaigneous rocks in the Mount Veta area of east-central Alaska: implications for the evolution of the westernmost part of the Yukon–Tanana terrane." Canadian Journal of Earth Sciences 50, no. 8 (August 2013): 826–46. http://dx.doi.org/10.1139/cjes-2013-0004.

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Анотація:

We report the results of new mapping, whole-rock major, minor, and trace-element geochemistry, and petrography for metaigneous rocks from the Mount Veta area in the westernmost part of the allochthonous Yukon–Tanana terrane (YTT) in east-central Alaska. These rocks include tonalitic mylonite gneiss and mafic metaigneous rocks from the Chicken metamorphic complex and the Nasina and Fortymile River assemblages. Whole-rock trace-element data from the tonalitic gneiss, whose igneous protolith was dated by SHRIMP U–Pb zircon geochronology at 332.6 ± 5.6 Ma, indicate derivation from tholeiitic arc basalt. Whole-rock analyses of the mafic rocks suggest that greenschist-facies rocks from the Chicken metamorphic complex, a mafic metavolcanic rock from the Nasina assemblage, and an amphibolite from the Fortymile River assemblage formed as island-arc tholeiite in a back-arc setting; another Nasina assemblage greenschist has MORB geochemical characteristics, and another mafic metaigneous rock from the Fortymile River assemblage has geochemical characteristics of calc-alkaline basalt. Our geochemical results imply derivation in an arc and back-arc spreading region within the allochthonous YTT crustal fragment, as previously proposed for correlative units in other parts of the terrane. We also describe the petrography and geochemistry of a newly discovered tectonic lens of Alpine-type metaharzburgite. The metaharzburgite is interpreted to be a sliver of lithospheric mantle from beneath the Seventymile ocean basin or from sub-continental mantle lithosphere of the allochthonous YTT or the western margin of Laurentia that was tectonically emplaced within crustal rocks during closure of the Seventymile ocean basin and subsequently displaced and fragmented by faults.

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33

Cui, Xiang, Wenbin Zhu, and F. Jourdan. "Subduction-related subcontinental lithospheric mantle metasomatism and crustal thickening: origin for superchondritic Nb/Ta in mafic dykes." Journal of the Geological Society 178, no. 1 (August 19, 2020): jgs2020–120. http://dx.doi.org/10.1144/jgs2020-120.

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Анотація:

Superchondritic Nb/Ta is rarely reported in terrestrial reservoirs and is usually attributed to carbonatite metasomatism or accessory rutile in the residue phase. Previously documented high Nb/Ta in rocks derived from subcontinental lithospheric mantle indicated a predominance of carbonatite metasomatism. This study evaluates Nb/Ta in conjunction with other trace elements of Neoproterozoic mafic dykes exposed in the eastern segment of the Jiangnan Orogen, where early subduction existed before the amalgamation of South China. These mafic dykes show mostly superchondritic Nb/Ta ratios from 19.6 to 24.5. Partial melting modelling suggested low-degree melting of rutile-bearing subcontinental lithospheric mantle for these mafic dykes. A literature review of Neoproterozoic mafic–intermediate rocks throughout the Jiangnan Orogen shows sporadically but coincidently superchondritic Nb/Ta near or beneath the Shuangxiwu arc, indicating rutile stability in the relict sub-arc mantle. Rutile in the lherzolite was formed sometime after Neoproterozoic subduction initiation in South China but contemporaneous with crustal thickening at c. 860 Ma. This study brings direct evidence to bear on the mechanism of rutile formation in the mantle wedge, as well as the link between crustal thickening and superchondritic Nb/Ta of mafic products derived from the metasomatized mantle.Supplementary material: Major and trace element compositions, photomicrographs of samples, and figures illustrating geochemistry, REE and incompatible trace element patterns and loss on ignition versus Nb/Ta and La/Yb are available at https://doi.org/10.6084/m9.figshare.c.5093535

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34

Handini, Esti, Toshiaki Hasenaka, Agung Harijoko, and Yasushi Mori. "Variation of Slab Component in Ancient and Modern Merapi Products: A Detailed Look into Slab Derived Fluid Fluctuation over the Living Span of One of the Most Active Volcanoes in Sunda Arc." Journal of Applied Geology 2, no. 1 (November 13, 2017): 1. http://dx.doi.org/10.22146/jag.30253.

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Holocene eruptions of Merapi have produced both medium-K and high-K calc alkaline series which correspond to products older and younger than 1900 years respectively. The change has been attributed to increasing sediment input as the volcano matures. This study presents two Merapi samples which represent Ancient and Modern Merapi. The two samples are analyzed for subduction components including B, Ba, Sr, and Pb using X-ray ﬂuorescence (XRF) spectrometer and prompt gamma ray analysis (PGA). Our ﬁnding shows that Ancient Merapi sample from Plawangan Hill lava is close in afﬁnities with younger than 1900 years high-K magma series. On the other hand, Modern Merapi sample from 2006 eruption juvenile is plotted within medium-K magma series which are observed in eruption products older than 1900 years. Ratios of ﬂuid mobile elements to high ﬁeld strength element (HFSE) (i.e. B/Nb, Ba/Y, Pb/Nb) consistently show that Ancient Merapi sample has higher input of slab derived ﬂuid than Modern Merapi sample. A model using B/Nb and Ba/Nb suggests that Plawangan magma requires 1.5 % of sediment derived ﬂuid, higher than estimated in 2006 eruption magma (1.2 %) and medium-K series magma, and within the range of high-K series magma, to explain its slab component enrichment. This evidence suggests that slab derived component addition to the sub-arc mantle wedge highly ﬂuctuates over short period of evolution of a volcano. One possible explanation is the presence of veined hydrous metasomatized sub-arc mantle as Merapi magma source which allows melting of different mantle area to produce ﬂuctuation of slab components in the course of evolution of Merapi magmas.

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35

Tilhac, Romain, Beñat Oliveira, William L. Griffin, Suzanne Y. O'Reilly, Bruce F. Schaefer, Olivier Alard, Georges Ceuleneer, Juan Carlos Afonso, and Michel Grégoire. "Reworking of old continental lithosphere: Unradiogenic Os and decoupled Hf Nd isotopes in sub-arc mantle pyroxenites." Lithos 354-355 (February 2020): 105346. http://dx.doi.org/10.1016/j.lithos.2019.105346.

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36

Xue, Shuo, and Yuan Li. "Pyrrhotite–silicate melt partitioning of rhenium and the deep rhenium cycle in subduction zones." Geology 50, no. 2 (November 9, 2021): 232–37. http://dx.doi.org/10.1130/g49374.1.

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Abstract The Re-Os isotopic system serves as an important tracer of recycled crust in Earth's deep mantle because of the large Re/Os ratios and time-integrated enrichment of radiogenic Os in Earth's crust. However, the Re distribution in Earth's known reservoirs is mass imbalanced, and the behavior of Re during subduction remains little understood. We performed laboratory experiments to determine the partition coefficients of Re between pyrrhotite and silicate melt () at 950–1080°C, 1–3 GPa, and oxygen fugacities (in log units relative to the fayalite-magnetite-quartz [FMQ] buffer) of FMQ–1.3 to FMQ +2. The obtained values are 200–25,000, which increase with decreasing oxygen fugacity and the total iron content (FeOtot) of silicate melt but decrease with increasing temperature or decreasing pressure. Applying to constrain the behavior of Re during slab melting demonstrates that slab melts contribute minimal Re to the sub-arc mantle, with most Re dissolved in sulfides subducted into Earth's deep mantle. Deep storage of recycled oceanic basalts and sediments can explain the mass imbalance of Re in Earth's primitive mantle, depleted mantle, and crust.

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37

Rollinson, H., J. Adetunji, A. A. Yousif та A. M. Gismelseed. "New Mössbauer measurements of Fe3+/ΣFe in chromites from the mantle section of the Oman ophiolite: evidence for the oxidation of the sub-oceanic mantle". Mineralogical Magazine 76, № 3 (червень 2012): 579–96. http://dx.doi.org/10.1180/minmag.2012.076.3.09.

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AbstractRoom temperature Mössbauer and electron-probe measurements of Fe3+/ΣFe in chromite from the mantle section of the Oman ophiolite define two groups of samples: a low Fe3+/ΣFe group (with Fe3+/ΣFe = 0.21–0.36) have cr# = Cr/(Cr + Al) in the range 0.49–0.75, whereas a smaller more geographically localized high Fe3+/ΣFe group (with Fe3+/ΣFe = 0.71–0.78) have a more restricted range of cr# ratios of 0.72–0.75. The low Fe3+/ΣFe chromitites have very variable Fe3+/ΣFe ratios. They are thought to have crystallized from melts that have interacted with depleted mantle and thereby acquired their variable Fe3+/ΣFe ratio. The high Fe3+/ΣFe chromitites are restricted to one small area of the mantle and their high oxidation state is thought to be post magmatic. They are either the product of later heating, related to melt flux or interaction with a later oxidising melt. A difference in oxygen fugacity between the MORB-depleted harzburgite host, which is at the quartz–fayalite–magnetite (QFM) buffer and the later chromite-bearing melts (QFM + 2) implies that there is a real difference in the oxidation state of the MORB and arc-magma sources.

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38

ALDANMAZ, E., M. K. YALINIZ, A. GÜCTEKIN, and M. C. GÖNCÜOĞLU. "Geochemical characteristics of mafic lavas from the Neotethyan ophiolites in western Turkey: implications for heterogeneous source contribution during variable stages of ocean crust generation." Geological Magazine 145, no. 1 (November 30, 2007): 37–54. http://dx.doi.org/10.1017/s0016756807003986.

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AbstractThe Late Triassic to Late Cretaceous age mafic lavas from the Neotethyan suture zone ophiolites in western Turkey exhibit a wide diversity of geochemical signatures, indicating derivation from extremely heterogeneous mantle sources. The rocks as a whole can be divided into three broad subdivisions based on their bulk-rock geochemical characteristics: (1) mid-ocean ridge basalts (MORB) that range in composition from light rare earth element (LREE)-depleted varieties (N-MORB; (La/Sm)N<1) through transitional MORB to LREE enriched types (E-MORB; (La/Sm)N>1); (2) the ocean island basalt (OIB)-type alkaline volcanic rocks with significant enrichment in LILE, HFSE and L-MREE, and a slight depletion in HREE, relative to normal mid-ocean ridge basalts (N-MORB); and (3) the supra-subduction zone (SSZ)-type tholeiites originated from arc mantle sources that are characterized by selective enrichments in fluid-soluble large ion lithophile elements (LILE) and LREE relative to the high field strength elements (HFSE). The formation of MORB tholeiites with variable enrichments and depletions in incompatible trace elements is probably related to the processes of crust generation along an oceanic spreading system, and the observed MORB–OIB associations can be modelled by heterogeneous source contribution and mixing of melts from chemically discrete sources from sub-lithospheric reservoirs. Evaluation of trace element systematics shows that the inferred heterogeneities within the mantle source regions are likely to have originated from continuous processes of formation and destruction of enriched mantle domains by long-term plate recycling, convective mixing and melt extraction. The origin of SSZ-type tholeiites with back-arc basin affinities, on the other hand, can be attributed to the later intra-oceanic subduction and plate convergence which led to the generation of supra-subduction-type oceanic crust as a consequence of imparting a certain extent of subduction component into the mantle melting region. Mixing of melts from a multiply depleted mantle source, which subsequently received variable re-enrichment with a subduction component, is suggested to explain the generation of supra-subduction-type oceanic crust. The geodynamic setting in which much of the SSZ-type ophiolitic extrusive rocks from western Turkey were generated can be described as an arc-basin system that is characterized by an oceanic lithosphere generation most probably associated with melting of mantle material along a supra-subduction-type spreading centre.

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39

Blein, Olivier, Henriette Lapierre, Richard A. Schweickert, Arnaud Pecher, and Cedric Reynaud. "Volcanisme triasique calco-alcalin a shoshonitique du Nevada occidental." Bulletin de la Société Géologique de France 172, no. 2 (March 1, 2001): 189–200. http://dx.doi.org/10.2113/172.2.189.

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Abstract Two types of island-arc occur in the North American Cordillera during the Permian-Triassic times. The first type is exposed in the eastern Klamath and Blue Mountains (fig. 1). Its stratigraphy is continuous from Permian to Triassic, and is composed of arc-tholeiites with minor calc-alkaline lavas. This suite shows high epsilon Nd (sub (T)) values similar to the range of intra-oceanic island-arc [Lapierre et al., 1987; Brouxel et al., 1987, 1988; Charvet et al., 1990; Lapierre et al., 1990, 1994]. In contrast, the second type, exposed in northern Sierra Nevada and central-western Nevada (Black Dyke) (fig. 1), is characterized by an early Permian calc-alkaline suite, with positive to negative epsilon Nd (sub (T)) values. Its basement is inferred to present continental affinities [Rouer et Lapierre, 1989; Rouer et al., 1989; Blein et al., 1996, 2000]. In western Nevada, volcanic rocks of early Triassic age are present in few localities: (1) the Triassic Koipato Group in central Nevada (fig. 1); (2) the Pablo Formation in the Shoshone mountains and the Paradise Range (figs. 1 and 2); and (3) the Garfield Flat formation in the Excelsior mountains (figs. 1 and 2). Silberling [1959] has subdivided the Pablo formation into three members: clastic, limestone, and greenstone (fig. 3). The clastic member consists of andesites, interbedded with volcaniclastic turbidites. The contact between the clastic and the limestone members is gradational and interlensing. The limestones are locally bioclastic with shell fragments, indicating a shallow-water deposition. They yielded a reworked late Permian fauna which suggests a late Permian or younger age. The clastic and limestone members could represent the recurrent rapid deposition in a shallow marine basin of volcanic flows, reworked material from a nearby terrane of volcanic, granitic, and sedimentary rocks. The greenstone member is composed of andesites, volcanic breccias and tuffs. The middle Triassic Granstville formation rests conformably on the Pablo formation. Both formations are affected by Mesozoic polyphase deformations [Oldow, 1985]. The Permian and/or Triassic Garfield Flat formation is composed of ignimbrites and pyroclastic breccia interlayered with conglomerates, sandstones, calcareous and red pelites (fig. 4). The Jurassic-Triassic Gabbs-Sunrise formation rests unconformably on the Garfield Flat formation. Both formations are affected by Mesozoic polyphase deformations [Oldow, 1985]. In the Pablo formation, lavas are shoshonitic basalts and calc-alkaline andesites, while calc-alkaline andesites and rhyolites predominate in the Garfield Flat formation. Basalts and andesites exhibit enriched LREE patterns (fig. 6) with slight negative anomalies in TiO 2 , Nb and Ta typical of subducted-related magmas in the primitive mantle-normalized spidergrams (fig. 7). The lavas show epsilon Sr (sub (T)) and epsilon Nd (sub (T)) values which range between -0.4 to +19.6, and -1.4 to +0.8 respectively (fig. 8). Most of the samples are displaced from the mantle array toward higher epsilon Sr (sub (T)) values, due to the alteration. The epsilon Nd (sub (T)) values, close to the Bulk Earth composition, record an interaction between material from a juvenile pole (mantle or young crust) and from an old crust. The Pablo and Garfield Flat formations differ from the Permian Black Dyke formation. This latter is characterized by calc-alkaline basalts and mafic andesites enriched in LREE, and a mantle source contaminated by subducted sediments or arc-basement [Blein et al., 2000]. The Pablo and Garfield Flat formations show many similarities with the Koipato Group. In central Nevada, the Koipato Group is a sequence of andesites, dacites and rhyolites interbedded with tuffs and volcaniclastic sediments. It rests with a marked angular unconformity on folded Upper Paleozoic oceanic rocks [Silberling and Roberts, 1962]. Fission-track dating on zircon [McKee and Burke, 1972] indicate an age of 225+ or -30 Ma for the Koipato Group. Ammonites, near the top, are considered to be upper early Triassic [Silberling, 1973]. The Pablo and Garfield Flat lavas share in common with the Koipato Group: (1) late Permian to middle Triassic ages; (2) abundant andesites and rhyolites with minor basalts, associated with felsic pyroclastic breccias; (3) LILE and LREE enrichement; (4) low epsilon Nd (sub (T)) values suggesting a juvenile source with slight contamination by a crustal component; (5) La/Nb ratios close to the lower limit of orogenic andesites [Gill, 1981]; and (6) high Nb/Zr ratios suggesting a generation far from a subduction zone [Thieblemont and Tegyey, 1994]. This Triassic high-K calc-alkaline to shoshonitic magmatism is enriched in K, Rb, Th, Nb and Ta relative to the calc-alkaline Black Dyke lavas, and is mainly juvenile judging from Nd isotopic ratios. The source may correspond either to a juvenile crust composed of high-K andesites [Roberts and Clemens, 1993], which could be the Black Dyke lavas, or to phlogopite-K-richterite enriched lithospheric mantle. In both cases, the generation of the high-K calc-alkaline magmatism needs the former existence of an important subduction phase to generate its source. The lavas of the Pablo and Garfield Flat formations are similar to calc-alkaline and shoshonitic lavas emitted in post-collisional setting. Post-collisional arc/continent magmatism is varied from intermediate to felsic, calc-alkaline to shoshonitic, low to high-K and meta-aluminous to hyper-aluminous. The studied lavas may be compared to the arc/passive margin collision of Papua-New Guinea, where a post-collisional magmatism characterized by high-K basalts, andesites and shoshonites [McKenzie, 1976]. In Nevada, this post-collisional event develops after the accretion of the Permian Black Dyke island-arc (Type 2), and before the accretion of the intra-oceanic Permo-Triassic arc (Type 1).

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40

Kerrich, Robert, and Chakravadhanula Manikyamba. "Contemporaneous eruption of Nb-enriched basalts – K-adakites – Na-adakites from the 2.7 Ga Penakacherla terrane: implications for subduction zone processes and crustal growth in the eastern Dharwar craton, India." Canadian Journal of Earth Sciences 49, no. 4 (April 2012): 615–36. http://dx.doi.org/10.1139/e2012-005.

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An association of Nb-enriched basalts (NEB), high-MgO andesites (HMA), and flows with adakitic characteristics are interlayered with tholeiitic pillow basalts in the 2.7 Ga Penakacherla greenstone belt of eastern Dharwar craton. Two populations of basalt are present, a high-Mg# Ni (0.65–0.56, 106–52 ppm) and low-Mg# Ni (0.45–0.34, 32–13 ppm) counterpart; Nb spans 6.3–18 ppm relative to “normal” arc tholeiitic basalts, where Nb ∼3 ppm, and hence qualify as NEB. Basalts plot on the low-Ce/Yb trend of intraoceanic arcs, and have fractionated heavy rare-earth elements (HREE) indicative of melting with residual garnet at >90 km. Ratios of Nb/Ta (7.6 ± 0.7), Zr/Hf (44 ± 0.8), and Zr/Sm (27 ± 2.4) are systematically low, high, and similar to respective primitive mantle ratios of 17, 36, and 25, consistent with a mid-ocean ridge basalt-like mantle source in the sub-arc mantle wedge. Intermediate compositions are divided into high-K but low-Na (K2O 1.8–5.3; Na2O 0.5–2.1 wt.%) and low-K but high-Na (K2O 0.10–1.5; Na2O 4.1–5.6 wt.%) populations defining distinct magma series; accordingly, these are termed K-adakitic and Na-adakitic rocks, respectively. The Na-type has SiO2 ≥56 wt.%, MgO <3 wt.%, Mg# ∼0.5, Na2O ≥3.5 wt.%, K2O ≤3 wt.%, Yb ≤1.9 ppm, Cr ≥30 ppm, with slightly lower limits of Al2O3 ≥15 wt.% and La/Yb 7.5–8.2 versus ≥20, thus conforming to most criteria for Na-adakites. NEB are interpreted as melts of mantle wedge hybridized by adakitic melts having residual garnet; and Na-adakites are slab melts of low-Mg basalt in the garnet–amphibolite facies. K-adakitic flows are melts of mafic lower crust, or melts of lower crust delaminated into mantle wedge asthenosphere.

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41

MIURA, Makoto, Shoji ARAI, and Akihiro TAMURA. "Formation of discordant chromitite at the initiation of sub-arc mantle processes: Observations from the northern Oman ophiolite." Journal of Mineralogical and Petrological Sciences 109, no. 1 (2014): 38–43. http://dx.doi.org/10.2465/jmps.131006.

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42

Marchesi, Claudio, Carlos J. Garrido, Joaquín A. Proenza, Károly Hidas, María Isabel Varas-Reus, Lidia Butjosa, and John F. Lewis. "Geochemical record of subduction initiation in the sub-arc mantle: Insights from the Loma Caribe peridotite (Dominican Republic)." Lithos 252-253 (May 2016): 1–15. http://dx.doi.org/10.1016/j.lithos.2016.02.009.

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43

Hu, Yan, Fang-Zhen Teng, and Dmitri A. Ionov. "Magnesium isotopic composition of metasomatized upper sub-arc mantle and its implications to Mg cycling in subduction zones." Geochimica et Cosmochimica Acta 278 (June 2020): 219–34. http://dx.doi.org/10.1016/j.gca.2019.09.030.

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44

Bouilhol, Pierre, James A. D. Connolly, and Jean-Pierre Burg. "Geological evidence and modeling of melt migration by porosity waves in the sub-arc mantle of Kohistan (Pakistan)." Geology 39, no. 12 (December 2011): 1091–94. http://dx.doi.org/10.1130/g32219.1.

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45

Tenzer, Robert, and Peter Vajda. "Global maps of the step-wise topography corrected and crustal components stripped geoids using the CRUST 2.0 model." Contributions to Geophysics and Geodesy 39, no. 1 (January 1, 2009): 1–17. http://dx.doi.org/10.2478/v10126-009-0001-9.

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Global maps of the step-wise topography corrected and crustal components stripped geoids using the CRUST 2.0 modelWe compile global maps of the step-wise topography corrected and crustal components stripped geoids based on the geopotential model EGM'08 complete to spherical harmonic degree 180 and the CRUST 2.0 global crustal model. The spectral resolution complete to degree 180 is used to compute the primary indirect bathymetric stripping and topographic effects on the geoid, while degree 90 for the primary indirect ice stripping effect. The primary indirect stripping effects of the soft and hard sediments, and the upper, middle and lower consolidated crust components are forward modeled in spatial form using the 2 × 2 arc-deg discrete data of the CRUST 2.0 model. The ocean, ice, sediment and consolidated crust density contrasts are defined relative to the adopted reference crustal density of 2670 kg/m3. Finally we compute and apply the primary indirect stripping effect of the density contrast (relative to the mantle) of the reference crust. The constant value of -520 kg/m3is adopted for this density contrast relative to the mantle. All data are evaluated on a 1 × 1 arc-deg geographical grid. The complete crust-stripped geoidal undulations, globally having a range of approximately 1.5 km, contain the gravitational signal coming from the global mantle lithosphere (upper mantle) morphology and density composition, and from the sub-lithospheric density heterogeneities. Large errors in the complete crust-stripped geoid are expected due to uncertainties of the CRUST 2.0 model, i.e., due to deviations of the CRUST 2.0 model density from the real earth's crustal density and due to the Moho-boundary uncertainties.

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46

Chen, Ling, Limei Tang, Xiaohu Li, Jie Zhang, Wei Wang, Zhenggang Li, Hao Wang, Xichang Wu, and Fengyou Chu. "Ancient Melt Depletion and Metasomatic History of the Subduction Zone Mantle: Osmium Isotope Evidence of Peridotites from the Yap Trench, Western Pacific." Minerals 9, no. 12 (November 20, 2019): 717. http://dx.doi.org/10.3390/min9120717.

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Highly depleted peridotites from the Yap Trench in the western Pacific Ocean have been studied for Re-Os elements and Re-Os isotopes. These peridotites have a low Re-Os content and variable 187Os/188Os ratios (0.12043–0.14867). The highest 187Os/188Os ratio is far higher than that of the primitive upper mantle and the lowest 187Os/188Os ratio is comparable to the most unradiogenic 187Os/188Os ratio (0.11933) discovered in subduction zone peridotites. The suprachondritic 187Os/188Os ratios of the Yap Trench peridotites results from modification of the mantle wedge by slab-derived fluid and melt. This is consistent with the observation that high 187Os/188Os ratios generally occur in oceanic peridotites with low Os content (<2 ppb) since Os may be reduced during late processes such as fluid alteration and melt refertilization. The sub-chondritic 187Os/188Os ratios of the Yap Trench peridotites correspond to a Re depletion age of 0.24–1.16 billion years, which means that these peridotites represent old mantle residue of ancient melting events. This ancient melting, combined with probable back-arc melting and forearc melting during subduction initiation, indicates that the Yap Trench mantle has a complex evolutionary history. The amount of old mantle residue in the oceanic asthenosphere was underestimated because the 187Os/188Os ratio in mantle peridotites is elevated during late processes. Therefore, old depleted mantle fragments may contribute substantially to the chemical heterogeneity of the oceanic mantle.

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47

Nan, Xiaoyun, Huimin Yu, Jinting Kang, and Fang Huang. "Re-visiting barium isotope compositions of mid-ocean ridge basalts and the implications." JUSTC 52, no. 3 (2022): 1. http://dx.doi.org/10.52396/justc-2021-0276.

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Barium (Ba) isotopes can be used as potential tracers for crustal material recycling in the mantle. Determination of the Ba isotope composition of the depleted mantle is essential for such applications. However, Ba isotope data for mantle-derived basalts are still rare. In this study, we reported high-precision Ba isotope data of 30 oceanic basalts including 25 mid-ocean ridge basalts (MORBs) from geochemically and geologically diverse mid-ocean ridge segments and five back-arc basin basalts. The δ<sup>138/134</sup>Ba values of these samples varied from −0.06‰ to +0.11‰, with no systematic cross-region variation. Together with published data, we constrained the average δ<sup>138/134</sup>Ba of global MORBs to +0.05‰±0.09‰ (2 standard deviation, <i>n</i> = 51). Based on depleted MORBs that have (La/Sm)<sub>N</sub> < 0.8, low <sup>87</sup>Sr/<sup>86</sup>Sr (< 0.70263), and low Ba/Th < 71.3, we estimated the average δ<sup>138/134</sup>Ba of the depleted MORB mantle (DMM) as + 0.05‰ ± 0.05‰ (2SD, <i>n</i> = 16) that is significantly lower than the DMM (≈ 0.14‰) reported previously. If a new estimation of the DMM is applied, it is unreasonable to infer that the Ba isotope signatures of the “enriched-type” MORBs (E-MORBs) could be attributed to pervasive sediment recycling in the upper mantle. We, therefore, conclude that the Ba isotope compositions of the E-MORBs could be sourced from the incorporation of subducted altered oceanic crust and/or sediments depending on the Ba isotope composition and other geochemical information of the local mantle.

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48

Bénard, A., O. Nebel, D. A. Ionov, R. J. Arculus, N. Shimizu, and N. Métrich. "Primary Silica-rich Picrite and High-Ca Boninite Melt Inclusions in Pyroxenite Veins from the Kamchatka Sub-arc Mantle." Journal of Petrology 57, no. 10 (October 2016): 1955–82. http://dx.doi.org/10.1093/petrology/egw066.

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49

Widom, Elisabeth, Pavel Kepezhinskas, and Mark Defant. "The nature of metasomatism in the sub-arc mantle wedge: evidence from Re–Os isotopes in Kamchatka peridotite xenoliths." Chemical Geology 196, no. 1-4 (May 2003): 283–306. http://dx.doi.org/10.1016/s0009-2541(02)00417-5.

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50

Tilhac, Romain, Michel Grégoire, Suzanne Y. O'Reilly, William L. Griffin, Hadrien Henry, and Georges Ceuleneer. "Sources and timing of pyroxenite formation in the sub-arc mantle: Case study of the Cabo Ortegal Complex, Spain." Earth and Planetary Science Letters 474 (September 2017): 490–502. http://dx.doi.org/10.1016/j.epsl.2017.07.017.

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