摘要
The tectonic activities occurring since the Cenozoic in the northern part of theQinghai-Tibet Plateau (the region from the East Kunlun Mountains to the Tanggula Mountains)were probably caused by the intense intraplate deformation propagation after the collision be-tween the Indian plate and the Eurasian plate. Their main expressions include the substantial up-lifting of the plateau, alternation of horizontal extension and compression under the verticalgreatest principal stress σ_1, occurrence of rift-type volcanic activity, formation of thebasin-range system, and successive eastward extrusion of blocks resulting from large-scalestrike-slip faulting. Geophysical exploration and experiments have revealed that there exist close-ly alternating horizontal high-velocity and low-velocity layers as well as lithospheric faults of aleft-lateral strike-slip sense in the lower part of the lithosphere (the lower crust and lithosphericmantle, 60-120 km deep). Based on an integrated study of the geological-geophysical data avail-able, the authors have proposed a model of deep-seated mantle diapir and the associatedtectonophysical process as the dynamic source for the uplift of the northern part of theQinghai-Tibet Plateau.
The tectonic activities occurring since the Cenozoic in the northern part of theQinghai-Tibet Plateau (the region from the East Kunlun Mountains to the Tanggula Mountains)were probably caused by the intense intraplate deformation propagation after the collision be-tween the Indian plate and the Eurasian plate. Their main expressions include the substantial up-lifting of the plateau, alternation of horizontal extension and compression under the verticalgreatest principal stress σ_1, occurrence of rift-type volcanic activity, formation of thebasin-range system, and successive eastward extrusion of blocks resulting from large-scalestrike-slip faulting. Geophysical exploration and experiments have revealed that there exist close-ly alternating horizontal high-velocity and low-velocity layers as well as lithospheric faults of aleft-lateral strike-slip sense in the lower part of the lithosphere (the lower crust and lithosphericmantle, 60-120 km deep). Based on an integrated study of the geological-geophysical data avail-able, the authors have proposed a model of deep-seated mantle diapir and the associatedtectonophysical process as the dynamic source for the uplift of the northern part of theQinghai-Tibet Plateau.
基金
This paper represents the result of the first-stage geological-geophysical integrated study of the Sino-French Cooperative Project"The Mechanism for Shortening of the Litbosphere in the East Kunlun and adjacent Regions"supported by the Ministry of Geol
