主题：Lithospheric foundering and underthrusting beneath Tibet revealed by adjoint tomography

时间：2016年11月29日10:00

地点：朱共山楼111

报告人：陈敏

报告人简介：

陈敏，籍贯：安徽省庐江县，现任美国莱斯大学地球科学系研究员。2001年于中国科技大学本科毕业，2008年在美国加州理工学院地球和行星科学系获得博士学位。先后分别在麻省理工学院和莱斯大学就任博士后。2014年主持美国国家自然科学基金项目从事中国大陆及邻近地区地壳和上地幔全波形层析成像的研究。

报告内容：

New tomographic images unveil a large-scale, high wave speed structure beneath South-Central Tibetin the middle to lower portions of the upper mantle. Lithospheric foundering induces an asthenospheric drag force,which drives continued underthrusting of the Indian continental lithosphere and associated shortening of the remainingTibetan lithosphere. We speculate that more recent asthenospheric upwelling leads to a thermal modificationof thickened lithosphere beneath Northern Tibet and subsequent surface uplift, consistent with the correlationof recent potassic volcanism and an imaged narrow low wave speed zone in the uppermost mantle. In contrast, theunusually high seismic wave speeds in the uppermost mantle beneath Southern Tibet, reminiscent of images beneaththe North American craton, suggest a possible prototype of modern craton formation due to continuedunder-accretion of Indian continent.