Os Isotopic and Platinum Group Element (PGE) Geochemistry of Oceanic Mantle: A Case Study from the Oman Ophiolite

推荐的项目是测量铂族元素（PGE），亲硫元素，和Os同位素组成的良好特征的纯橄榄岩和方辉橄榄岩从阿曼蛇绿岩，代表残留样品的仰冲洋幔。 主要目标是确定大洋中脊玄武岩（MORB）地幔源的Os同位素和PGE组成，主要是测试它是否具有从玄武岩（如深海和深海橄榄岩）中分离出来的地幔Os和PGE特征。 该提案还将研究岩浆和蚀变过程中的铂族元素流动性，特别考虑熔体输送和裸露岩石风化过程中的围岩相互作用是否会改变铂族元素值。 这项工作将提供重要的限制有关的MORB源的起源，并应有助于解决地球化学矛盾之间的蛇绿岩和深海橄榄岩关于他们是否都是MORB熔融的残留物。

Recommended project is for measurement of the platinum group elements (PGE), chalcophile elements, and Os isotopic compositions on well-characterized dunites and harzburgites from the Oman ophiolite, representing relict samples from obducted oceanic mantle. The major goal is to determine the Os isotopic and PGE composition of the mid-ocean ridge basalt (MORB) mantle source, principally to test whether it has chondritic Os and PGE signatures that are fractionated from chondrites (as are abyssal and massif peridotites). The proposal will also examine PGE mobility during magmatic and alteration processes, considering specifically whether wall-rock interaction during melt transport and weathering of exposed rock can change PGE values. This work will provide important constraints regarding the origin of the MORB source, and should help to resolve geochemical contraditions presented between ophiolites and abyssal peridotites regarding whether they are both residues of MORB melting.