Fission track thermochronology evidence for Mesozoic-Cenozoic uplifting of Daba Mountain,central China.

Studying on the Mesozoic-Cenozoic uplifting of Daba Mountain is an important significance to understand the tectonic evolution of Qinling orogeny roundly.And it is instructional value for petroleum exploration of Northeast Sichuan Basin.Apatite fission track dating and time-temperature thermal history modeling were carried to analyze on 18 samples in the Daba Mountain.The results indicate that the Mesozoic-Cenozoic uplifting process of Daba Mountain since the Cretaceous can be divided into three stages and show continuous uplifting and cooling.The uplifting age bear juvenility gradually from northeast to southwest,which indicated the increase disciplinary of extrusion thrusting and folding uplifting in Daba Mountain.The early rapid uplifting cooling event at 120～110 Ma is the embodiment of the Cretaceous territorial uplifting and exhumation event of Qinling orogeny.Following by a period of relative thermal stability,the rocks kept at apatite partial annealing zone temperatures,and ending with a new phase of accelerated uplifting during 10～6 Ma to resent.This accelerated uplifting event is response to eastward growth of the Tibetan Plateau uplift and lateral growth, which continues today.