Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6438052 | Geochimica et Cosmochimica Acta | 2015 | 19 Pages |
Abstract
The modeling curves of fluids derived from a dehydrated slab (ratios: AOC80-SED20 to AOC40-SED60) with a representative mantle composition can account for the majority of lithium compositional variations. Some samples with unusual Pb-Sr-Nd-O isotopic compositions and highly variable δ7Li compositions are affected by significant involvement of marine sediments in their source region, not contaminated by crustal materials. The carbonatites and syenites in western Sichuan were generated by the partial melting of subcontinental lithospheric mantle, which was metasomatized by the Li-rich fluids derived from the subducted oceanic crust and marine sediments. This melting was most likely triggered by a Cenozoic asthenospheric mantle diapir related to Indian-Asian continental collision and post- or late-collisional stress relaxation in the Oligocene.
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Authors
Shihong Tian, Zengqian Hou, Aina Su, Lin Qiu, Xuanxue Mo, Kejun Hou, Yue Zhao, Wenjie Hu, Zhusen Yang,