School of Earth Sciences, Zhejiang University, Hangzhou, 310027, China.
School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, China.
Nat Commun. 2017 Nov 28;8(1):1824. doi: 10.1038/s41467-017-01940-3.
The genesis of large igneous provinces (LIP) is controlled by multiple factors including anomalous mantle temperatures, the presence of fusible fertile components and volatiles in the mantle source, and the extent of decompression. The lack of a comprehensive examination of all these factors in one specific LIP makes the mantle plume model debatable. Here, we report estimates of the water content in picrites from the Emeishan LIP in southwestern China. Although these picrites display an island arc-like HO content (up to 3.4 by weight percent), the trace element characteristics do not support a subduction zone setting but point to a hydrous reservoir in the deep mantle. Combining with previous studies, we propose that hydrous and hot plumes occasionally appeared in the Phanerozoic era to produce continental LIPs (e.g., Tarim, Siberian Trap, Karoo). The wide sampling of hydrous reservoirs in the deep mantle by mantle plumes thus indicates that the Earth's interior is largely hydrated.
大火成岩省（LIP）的成因受到多种因素的控制，包括异常的地幔温度、地幔源中易熔的肥沃成分和挥发分的存在，以及减压的程度。由于没有综合考虑一个特定的 LIP 中的所有这些因素，地幔柱模型存在争议。在这里，我们报告了中国西南部峨眉山大火成岩省中苦橄岩的含水量估计值。尽管这些苦橄岩显示出类似于岛弧的 HO 含量（高达 3.4 重量百分比），但其微量元素特征并不支持俯冲带环境，而是指向深部地幔中的含水储层。结合以前的研究，我们提出，含水和热地幔柱偶尔会出现在显生宙时期，从而产生大陆大火成岩省（如塔里木、西伯利亚陷阱、卡鲁）。地幔柱对深部含水储层的广泛采样表明，地球内部在很大程度上是含水的。
