Detection of Widespread Fluids in the Tibetan Crust by Magnetotelluric Studies
Detection of Widespread Fluids in the Tibetan Crust by Magnetotelluric Studies
复制标题
DOI：
10.1126/science.1010580
复制
发表时间：
2001-04
期刊：
影响因子：
56.9
通讯作者：
Wenbo Wei;M. Unsworth;A. Jones;J. Booker;H. Tan;D. Nelson;Leshou Chen;Shenghui Li;K. Solon-K.-So
中科院分区：
文献类型：
--
作者：
Wenbo Wei;M. Unsworth;A. Jones;J. Booker;H. Tan;D. Nelson;Leshou Chen;Shenghui Li;K. Solon-K.-So
大地电磁勘探表明，青藏高原南北宽的大部分地区的中、下地壳都是负导电的。西藏地壳的综合电导率（电导率）范围从3000到大于20,000西门子。相比之下，稳定的大陆区域通常表现出20到1000西门子的电导率，平均为100西门子。这种普遍的高电导率表明，部分熔融和/或含水流体广泛分布在西藏地壳内。在西藏南部，高导层位于15至20公里的深度，可能是由于地壳中的部分熔融和含水流体。在西藏北方，导电层在30至40公里处，是由于部分融化。流体区可能代表较弱的区域，可以容纳变形和较低的地壳流动。
Magnetotelluric exploration has shown that the middle and lower crust is anomalously conductive across most of the north-to-south width of the Tibetan plateau. The integrated conductivity (conductance) of the Tibetan crust ranges from 3000 to greater than 20,000 siemens. In contrast, stable continental regions typically exhibit conductances from 20 to 1000 siemens, averaging 100 siemens. Such pervasively high conductance suggests that partial melt and/or aqueous fluids are widespread within the Tibetan crust. In southern Tibet, the high-conductivity layer is at a depth of 15 to 20 kilometers and is probably due to partial melt and aqueous fluids in the crust. In northern Tibet, the conductive layer is at 30 to 40 kilometers and is due to partial melting. Zones of fluid may represent weaker areas that could accommodate deformation and lower crustal flow.