Publication 76

Widespread fluids in the Tibetan crust

Wei, W., M. Unsworth, A.G. Jones, T. Handong, K.D. Nelson, J.R. Booker, L. Chen, S. Li, K. Solon, P. Bedrosian, S. Jin, M. Deng, J. Ledo, D. Kay and B. Roberts


Magnetotelluric (MT) 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 S, averaging 100 S. 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 15-20 km and probably due to partial melt and aqueous fluids in the crust. In Northern Tibet the conductive layer is at 30-40 km and due to partial melting. Zones of fluid may represent weaker areas that could accommodate deformation and lower crustal flow.


Science, 292, 716-718, 2001.

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Alan G Jones / 10 June 2004 /