Fission track dating of 0 - 4000m core samples from main hole of the Chinese Continental Scientific Drilling
中国大陆科学钻探主孔0-4000m岩心的裂变径迹年龄测定

A fission track analysis was carried out on the core samples from 0 - 4000m in main hole of the Chinese Continental Scientific Drilling (CCSD). Fission track ages of 38 apatite samples from different depthes were dated. The distribution of them is between 98. 6 - 3. 2Ma, and the values reduce gradually with depth increasing. The fission track age of surface sample is 87.6Ma, but ones 3. 2Ma on the 3899m depth sample. It shows that the temperature of crust goes up with increasing of depth besed on the characteristic of fission track anealing. The variation of ages, however, has some fluctuation. For example, it is uncontinuous between 1550 - 2450m depth. This segment would be a important tectonic belt. Discussing the thermotectonic history and the exhumation machanism of ultrahigh pressure metamorphic rock in later period.