Evidence for a dominantly reducing Archaean ambient mantle from two redox proxies, and low oxygen fugacity of deeply subducted oceanic crust
نویسندگان
چکیده
منابع مشابه
Geochemical heterogeneity and element mobility in deeply subducted oceanic crust; insights from high-pressure mafic rocks from New Caledonia
Bulk-rock major and trace element geochemistry of a range of eclogite, garnet blueschist and garnet amphibolite rocks from northern New Caledonia has been determined in order to geochemically characterise subducted oceanic crust. The rocks experienced peak metamorphic conditions of 1.9 GPa and 600 jC and represent excellent samples of oceanic crust that was subducted to depths of approximately ...
متن کاملSeismic array detection of subducted oceanic crust in the lower mantle
[1] We analyze short-period precursory energy to PP that can be observed in seismograms in the distance range from 95 to 105 to infer the behavior of subducted slabs beneath western Pacific subduction zones. PP is a P wave once reflected at the free surface between the source and receiver. Using high-resolution seismic array techniques, we analyze the incidence angle, timing, and azimuth of the...
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Understanding of the geochemistry of the chalcophile elements [i.e., Os, Ir, Ru, Pt, Pd (platinum-group elements), and Au, Cu, Ni] has been informed for at least 20 years by the common assumption that when crust-forming partial melts are extracted from the upper mantle, sulfide liquid in the restite sequesters chalcophile elements until the extent of partial melting exceeds approximately 25% an...
متن کاملOXYGEN FUGACITY OF THE MARTIAN BASALTS FROM ANALYSIS OF Fe-Ti OXIDES: IMPLICATIONS FOR MANTLE-CRUST INTERACTION ON MARS
Synopsis: The oxygen fugacity of the basaltic martian meteorites has been calculated from thermodynamic models involving spinel-ilmenite equilibria. The wide range of estimates, from near the IW buffer to near QFM, may be explained by mixing of mantlederived melts with oxidized material in the martian crust. Possible oxidized crustal end-members are considered. Analytical Method and Results: Sp...
متن کاملMicrobial Inventory of Deeply Buried Oceanic Crust from a Young Ridge Flank
The deep marine biosphere has over the past decades been exposed as an immense habitat for microorganisms with wide-reaching implications for our understanding of life on Earth. Recent advances in knowledge concerning this biosphere have been achieved mainly through extensive microbial and geochemical studies of deep marine sediments. However, the oceanic crust buried beneath the sediments, is ...
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ژورنال
عنوان ژورنال: Scientific Reports
سال: 2019
ISSN: 2045-2322
DOI: 10.1038/s41598-019-55743-1