The Paleotopography Reconstruction of Late Cretaceous Dabie Orogen by Low-temperature Thermochronological Age-elevation Relationships

摘要

The paleotopography reconstruction of orogen has an important research value on the study of mountain building and the study of orogen's regional control over the paleoclimate change. Considering the Dabie orogen's regional difference in exhumation, this article models the post-orogenic exhumation rates and the relief evolution rates by low-temperature thermochronology and age-elevation relationships. The result shows that the mean exhumation rates (0.07～ 0.08km/Ma) of the middle block, the southwest block, and the southeast block are higher than the rate (0.06 km/Ma) of the northwest block and the northeast block. The relief evolution rate of the northeast block (3.5) is the highest, the middle block (3.0) follows, the southeast block (2.5) goes after, and those of the north-west block and south-west block (2.0,1.5) are the lowest. This is might be related to the thermal doming extensional structure of Dabie orogen in Cretaceous.