近日，中国科学院广州地球化学研究所王强团队报道了重硅同位素地幔储层的发现。2025年9月24日出版的《国家科学评论》杂志发表了这项成果。
地球储层之间的硅循环为了解地球的运作方式提供了重要的见解。虽然平均花岗岩和大块硅酸盐土（BSE）具有相似的硅同位素（δ30Si）组成，但一些幔源岩浆的δ30Si值低于BSE，这意味着存在一个未识别的地幔储层，其δ30Si值互补较高。
这些幔源岩的δ30Si值高于BSE，源于地幔橄榄岩与俯冲的印度大陆红砾中富含30Si的硅酸盐熔体相互作用的结果。结果表明，板坯熔炼可以产生高δ30Si熔体和互补的低δ30Si残留物。这些产物在地幔中的分布不均匀，高δ30Si的熔体以交代脉的形式储存在岩石圈地幔中，而低δ30Si的残留物则循环进入深部地幔。该研究提供了高δ30Si板块熔体的地幔交代作用在大陆板块之上的岩石圈地幔或大洋板块之上的冷地幔楔中形成重硅储层的证据。
附：英文原文
Title: Discovery of a heavy silicon isotope mantle reservoir
Author: Liu, Mao-Rui, Wang, Jun, Cui, Ze-Xian, Wei, Gang-Jian, Yang, Qing, Xu, Yi-Gang, Kerr, Andrew C, Wyman, Derek, Bai, Jiang-Hao, Zhu, Guan-Hong, Ma, Lin, Hao, Lu-Lu, Zhou, Jin-Sheng, Fan, Jing-Jing, Huang, Tong-Yu, Zhang, Miao-Yan, Wang, Qiang
Issue&Volume: 2025-09-24
Abstract: Silicon cycling between Earth’s reservoirs provides critical insights into how the Earth operates. While average crust and the Bulk Silicate Earth (BSE) share similar silicon isotope (δ30Si) compositions, some mantle-derived magmas exhibit lower δ30Si values than the BSE, implying the existence of an unidentified mantle reservoir with complementary higher δ30Si values. We present silicon isotope data from Cenozoic lamproites and their hosted mantle pyroxenite xenoliths from the Himalaya-Tibet orogen. These mantle-derived rocks have higher δ30Si values than the BSE, which resulted from reaction between mantle peridotite and 30Si-rich silicate melts from subducted Indian continental crust. Our results demonstrate that slab melting can produce high-δ30Si melts and complementary low-δ30Si residues. These products are unevenly distributed in the mantle - with high-δ30Si melts stored as metasomatic veins in the lithospheric mantle while low-δ30Si residues are recycled into deep mantle. This study provides evidence that mantle metasomatism by high-δ30Si slab melts creates heavy silicon reservoirs in the lithospheric mantle above continental slabs or cool mantle wedges above oceanic slabs.
DOI: 10.1093/nsr/nwaf410
Source: https://academic.oup.com/nsr/advance-article/doi/10.1093/nsr/nwaf410/8262908searchresult=1