Abstract:

The research on the Cretaceous basin evolution of Liupanshan is crucial for understanding the formation of the Cretaceous and present China tectonic-environmental pattern. The paleomagnetic study of the Liupanshan Group in the Huoshizhai section in the central-northern Liupanshan basin yielded an age control on the Liupanshan Group at 110-130 Ma. Combined with the regional tectonic data the magnetostratigraphic results depicted that the Liupanshan basin was a rift-related depression basin and had undergone the early extension stage spanning in the period of 125.3-129.6 Ma, the middle expansion and stable depression stage during 109.6-125.3 Ma and the late extinction stage during 102.0-109.6 Ma. The age of the early extension stage is good to match with the time constraint obtained by the most studies of main duration of the tectonic extension in the east of China continent, indicating that this stage is the respondence to the lithospheric mantle detachment and geodynamic system transformation in the east of China continent.

Key words: magnetostratigraphy, Early Cretaceous, Liupanshan Group, tectonic implication