Fission track analytical res ults about tectonothermal evolution and metallogenic processes show that Lanping Basin at least undergoes three stages of tectonothermal events, accompanied by three stages of metallogenic processes which develop gradually from western edg e to the center of the basin.
Fission-track ages for these samples range from 9．6±0．8 to 89．2±2．3 Ma with mean track lengths varying from 7．9±3．7 to 11．6±1．9 μm. The apatite fission track ages from various geographical regions suggest difference in styles of cooling during the Mesozoic－Cenozoic.
The apatite fission track ages are 59.4±3.4 ～105.6±9.8 Ma in eastern Dabie area, which show the characteristics of wide range, inhomogeneous distribution and asymmetric pattern, and discontinuity along main faults' striking and dipping.
According to the determination of apatite fission track ages and length, the annealing characteristics of apatite fission track, geothermal evolution and prediction of petroleum source in studied area are discussed.
The zircon fission track ages range from 158 Ma to 289 Ma and the apatite ages are between 64 Ma and 140 Ma.
Corresponding to apatite fission track ages, the three tectonic-mineralizing epochs are 140-132 Ma, 109-97 Ma and 64 Ma, which means age at about 100°C after the mineralization.
Fission track ages have been measured for 12 sphenes, 18 zircons and 25 apatites separated largely from Lower Tertiary magmatic rocks of East Greenland, with a few examples from Caledonian rocks.
Tectonic interpretation of an inverse gradient of zircon fission-track ages with respect to altitude: alpine thermal history of
The beta-ray spectrum of RaE was investigated by the cloud chamber experiments. About 600 tracks with H σ above 2000 were obtained. The spectrum was found to have an end point at 7500 Hσ. The average energy per disintegration was estimated to be 4.01×105 electron-volts.