scholarly journals Subduction-Induced Fractionated Highly Siderophile Element Patterns in Forearc Mantle

Minerals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 339 ◽  
Author(s):  
Yang Xu ◽  
Chuan-Zhou Liu
Keyword(s):  
New Caledonia ◽  
Melt Extraction ◽  
Highly Siderophile Elements ◽  
Group I ◽  
Mantle Peridotites ◽  
Tectonic Settings ◽  
Siderophile Elements ◽  
Fe Alloys ◽  
Slab Dehydration ◽  
Forearc Mantle

Compositions of highly siderophile elements (HSEs) in forearc mantle have been little studied and effects of slab dehydration on their abundances in forearc mantle remains unclear. This study reports two different kinds of HSE patterns for peridotites from a New Caledonia forearc ophiolite. The Group-I samples show relatively flat patterns of Ir-group-platinum-group elements (IPGEs) and enrichment of Pt over Pd. Such patterns imply that interstitial sulfides were significantly removed through melt extraction, whereas sulfides enclosed within silicates were mostly unaffected. Meanwhile, Pt-Fe alloys were generated, resulting in suprachondritic Pt/Pd ratios. In contrast, the Group-II samples display convex HSE patterns and are depleted in all HSEs except for Ru, yielding strongly positive Ru anomalies. This indicates that both enclosed and interstitial sulfides were substantially consumed, whereas chromite was generated to stabilize Ru. Compared to abyssal peridotites, subduction-related peridotites commonly have stronger fractionation in the HSEs. Therefore, the HSE data of mantle peridotites are potentially able to discriminate the tectonic settings of ophiolites.

Highly siderophile elements and Sr–Nd isotopes in refertilized mantle peridotites — A case study from the Totalp ultramafic body, Swiss Alps

2010 ◽  
Vol 276 (3-4) ◽  
pp. 257-268 ◽  
Author(s):  
David van Acken ◽  
Harry Becker ◽  
Konrad Hammerschmidt ◽  
Richard J. Walker ◽  
Frank Wombacher
Keyword(s):  
Swiss Alps ◽  
Nd Isotopes ◽  
Highly Siderophile Elements ◽  
Mantle Peridotites ◽  
Siderophile Elements

Petrology and geochemistry of mantle peridotites from the Kalaymyo and Myitkyina ophiolites (Myanmar): Implications for tectonic settings

Lithos ◽  
2016 ◽  
Vol 264 ◽  
pp. 495-508 ◽  
Author(s):  
Chuan-Zhou Liu ◽  
Chang Zhang ◽  
Yang Xu ◽  
Jian-Gang Wang ◽  
Yi Chen ◽  
...  
Keyword(s):  
Mantle Peridotites ◽  
Petrology And Geochemistry ◽  
Tectonic Settings

Stochastic Late Accretion to Earth, the Moon, and Mars

Science ◽  
2010 ◽  
Vol 330 (6010) ◽  
pp. 1527-1530 ◽  
Author(s):  
William F. Bottke ◽  
Richard J. Walker ◽  
James M. D. Day ◽  
David Nesvorny ◽  
Linda Elkins-Tanton
Keyword(s):  
Size Distribution ◽  
Asteroid Belt ◽  
The Moon ◽  
Core Formation ◽  
Highly Siderophile Elements ◽  
Earth’S Mantle ◽  
Distribution Matching ◽  
Siderophile Elements ◽  
Impact Basins

Core formation should have stripped the terrestrial, lunar, and martian mantles of highly siderophile elements (HSEs). Instead, each world has disparate, yet elevated HSE abundances. Late accretion may offer a solution, provided that ≥0.5% Earth masses of broadly chondritic planetesimals reach Earth’s mantle and that ~10 and ~1200 times less mass goes to Mars and the Moon, respectively. We show that leftover planetesimal populations dominated by massive projectiles can explain these additions, with our inferred size distribution matching those derived from the inner asteroid belt, ancient martian impact basins, and planetary accretion models. The largest late terrestrial impactors, at 2500 to 3000 kilometers in diameter, potentially modified Earth’s obliquity by ~10°, whereas those for the Moon, at ~250 to 300 kilometers, may have delivered water to its mantle.

scholarly journals Highly siderophile elements mobility in the subcontinental lithospheric mantle beneath southern Patagonia

Lithos ◽  
2018 ◽  
Vol 314-315 ◽  
pp. 579-596 ◽  
Author(s):  
Santiago Tassara ◽  
José M. González-Jiménez ◽  
Martin Reich ◽  
Edward Saunders ◽  
Ambre Luguet ◽  
...  
Keyword(s):  
Lithospheric Mantle ◽  
Subcontinental Lithospheric Mantle ◽  
Highly Siderophile Elements ◽  
Southern Patagonia ◽  
Siderophile Elements
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