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Yunkaidashan, located at the southern South China block (SCB) and closely adjacent to the Indochina block, is an ideal region for better understanding the tempo- ral and spatial framework of tectonothermal overprinting at the southern SCB since Mesozoic. Apatite and zircon fission track thermochronology of various-type rocks from Yunkai- dashan is presented in this paper. The results show, no mat- ter what rocks are, the apparent ages of zircon fission track range from 97.4 to 133.0 Ma, and those of apatite fission track from 43.2 to 68.4 Ma. The length of apatite fission track yields an average confined track length of ~13 μm and shows normal distribution of unimodal frequency. It is in- ferred that the uplifting amplitude has been more than 5 km in Yunkaidashan since late Mesozoic. The difference of fis- sion track apparent ages at different locations in Yunkai- dashan suggests a paleophysiognomic scenario of the hetero- geneous uplift/denudation. These data of the fission track thermochronology provide new constraints for better under- standing the tectonophysiognomic pattern of the SCB since late Mesozoic.
Yunkaidashan, located at the southern South China block (SCB) and closely adjacent to the Indochina block, is an ideal region for better understanding the tempo- ral and spatial framework of tectonothermal overprinting at the southern SCB since Mesozoic. Apatite and zircon fission track thermochronology of various-type rocks from Yunkai- dashan is presented in this paper. The results show, no mat- ter what rocks are, the apparent ages of zircon fission track range from 97.4 to 133.0 Ma, and those of apatite fission track from 43.2 to 68.4 Ma. The length of apatite fission track yields an average confined track length of ~ 13 μm and shows normal distribution of unimodal frequency. It is in- ferred that the uplifting amplitude has been more than 5 km in Yunkaidashan since late Mesozoic. The difference of fis- sion track apparent ages at different locations in Yunkai- dashan suggests a paleophysiognomic scenario of the hetero- geneous uplift / denudation. These data of the fission track the rmochronology provide new constraints for better under- standing the tectonophysiognomic pattern of the SCB since late Mesozoic.