Abstract:

 The research on the Cretaceous climate is crucial for understanding the formation of the present global environmental pattern. The previous records of the Cretaceous climate were obtained from the marine sediments. In this study, based on the analyses of the sedimentary and susceptibility data of the sediments of the Liupanshan Group exposed in the Liupanshan area (central China), we obtained the climate records during 1281511582 Ma from the terrigenous sediments. The susceptibility values are lower totally and can be classified into two segments, i.e. the lower values prior to 125 Ma and the higher values after 125 Ma. The analysis of the sedimentary environment, of the contents of magnetic minerals and the TFe in the rocks, and of their relationship with the susceptibility enhancement suggested that the susceptibility values are predominantly determined by the kinds and the contents of the magnetic minerals from the source region, which indicated that the susceptibility values can be used to interpret the climate change in this time window. The climate during 1281511582 Ma was significantly arid and hot. Moreover, the variation of the susceptibility values revealed that the climate changed at ca. 125 Ma from relatively wet and hot during 12815125 Ma to relative wet and warm during 12511582 Ma. This is consistent with the variation of the global sea surface temperature (SST), but the time of this transition was 17 Ma earlier than the time of remarkable change of the global SST recorded by the marine sediments, which probably suggested that the continent was more sensitive to the climate change than the ocean.

Key words: magnetic susceptibility, climate change, Liupanshan Group, Early Cretaceous