Geologic Investigation of Cenozoic Volcanic Rocks in the Qiangtang Region of Northern Tibet (National Geographic Society; 2006)

One of the most volatile debates in geoscience today concerns how continents deform during collision. Do continents subduct like oceanic plates or do they thicken homogeneously, with deeper parts dripping off like in a lava lamp? Also, to what extent do continents escape laterally away from collision? All of the above processes have been suggested to have occurred, or be presently occurring, in northern Tibet due to ongoing India-Asia collision. While these processes make distinct predictions regarding rock deformation and its temporal and spatial relations with volcanism, their relative importance remains unknown. This is in large part due to the scarcity of geologic studies in the Qiangtang region of northern Tibet, one of the most remote and highest elevated (>5 km) regions on Earth.

This project, to commence in May, 2006, involves mapping and sampling collision-related volcanic fields in northern Tibet. The volcanic rocks will be dated to constrain the magmatic history and provide slip rates for faults that cut the volcanic rocks. Studies of fragments of deep crust and mantle entrained in the lavas as they traveled to the surface will provide insight into the structure of the continent and how it evolved through time. The results will lead to a better understanding of how continents behave during collision and yield new estimates for when the crust was thickened-and hence when the Plateau achieved its high elevation. The latter is fundamental to testing the hypothesis that the uplift of Tibet directly influenced global climate and ocean-water chemistry.