The origin of rare alkali metals in geothermal fluids of southern Tibet, China: A silicon isotope perspective
The origin of rare alkali metals in geothermal fluids of southern Tibet, China: A silicon isotope perspective
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中国西藏南部地热流体中稀有碱金属的起源：硅同位素视角
DOI：
10.1038/s41598-019-44249-5
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发表时间：
2019-05
影响因子：
4.6
通讯作者：
Wu He-Pin
中科院分区：
文献类型：
--
作者：
Wang Wei D;Wei Hai-Zhen;Jiang Shao-Yong;Tan Hong-Bing;Eastoe Christopher J.;Williams-Jones Anthony E.;Hohl Simon V.;Wu He-Pin
藏南狮泉河-雅鲁藏布江地热田的塞米、达戈加和卡乌温泉的地热沃茨中富含稀有碱金属。然而，浓缩机制仍在激烈辩论中。在这里，我们报告了这些地热沃茨的第一个硅同位素数据，以解开极端RAM富集的起源。泉孔的烧结沉淀和深部储层的水岩作用控制了硅收支和硅同位素分馏。三个泉点的水岩作用速率和烧结矿降水速率分别为塞米>卡务>大葛家和大葛家>卡务>塞米。硅同位素分馏在烧结沉淀过程中（Δ 30 Si沉淀-溶液<-0.1 ‰）小于水-岩作用过程中（Δ 30 Si沉淀-岩石至少高达-0.47 ‰），这使得利用泉水的δ 30 Si特征来评价水-岩作用强度成为可能。基于现有证据，提出了RAM富集的概念模型：（i）藏南持续的岩浆活动为RAM在寄主岩石中的初始富集提供了条件，并为地热系统的深部储层提供了热源;（ii）高Cl−含量和长停留时间（数千年）促进了RAM从硅酸盐寄主岩石中的淋溶。
Geothermal waters from the Semi, Dagejia and Kawu hot springs in the Shiquanhe-Yarlung Zangbo geothermal field of southern Tibet (China) are highly enriched in rare alkali metals (RAM). However, the enrichment mechanism is still hotly debated. Here, we report the first silicon isotope data of these geothermal waters to unravel the origin of the extreme RAM enrichments. Sinter precipitation in the spring vents and water-rock interaction in the deep reservoir controlled both the silicon budget and silicon isotope fractionation. The rates of water-rock interaction and sinter precipitation in three spring sites decrease in the sequences Semi > Kawu > Dagejia, and Dagejia > Kawu > Semi respectively. Silicon isotope fractionation during sinter precipitation (i.e. Δ30Siprecipitate-solution< −0.1‰) is less than that due to water-rock interaction (i.e. Δ30Sisolution-rocksat least as high as −0.47‰), which makes it possible to use the δ30Si signatures of springs to evaluate the intensity of water-rock interaction. Based on the available evidence, a conceptual model of RAM enrichment is proposed: (i) persistent magmatic activity in southern Tibet provided the initial enrichment of the RAM in host rocks and a heat sources for the deep reservoirs of geothermal systems; (ii) the high Cl−content and long residence time (thousands of years) promote the leaching of RAM from the silicate host rocks.
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DOI：
10.1007/s11631-012-0580-4
发表时间：
2012-07
期刊：
Chinese Journal of Geochemistry
影响因子：
--
作者：
Zhiyou Gao;Xiaodan Wang;Guan Yin
通讯作者：
Zhiyou Gao;Xiaodan Wang;Guan Yin
影响因子：
5
作者：
F. Poitrasson;T. Zambardi
通讯作者：
F. Poitrasson;T. Zambardi
DOI：
10.1007/bf02911969
发表时间：
2001-12
期刊：
--
影响因子：
--
作者：
Hou Zengqian;Lin Zhenqing;Qu Xiaoming;Gao Yongfeng;Hua Lichen;Zheng Mianping;L. Shengrong;Yuan Wanming
通讯作者：
Hou Zengqian;Lin Zhenqing;Qu Xiaoming;Gao Yongfeng;Hua Lichen;Zheng Mianping;L. Shengrong;Yuan Wanming
影响因子：
5
作者：
M. Palmer;N. Sturchio
通讯作者：
M. Palmer;N. Sturchio
DOI：
10.1360/yd2001-44-s1-35
发表时间：
2001-10
期刊：
Science in China Series D: Earth Sciences
影响因子：
--
作者：
Zq Hou;ZQ Li;Xm Qu;Yf Gao;Lc Hua;Mp Zheng;Li;W. Yuan;袁万明
通讯作者：
Zq Hou;ZQ Li;Xm Qu;Yf Gao;Lc Hua;Mp Zheng;Li;W. Yuan;袁万明