The character and origin of sequence architecture in the arid climate zone: A case of the Lower Submember of the Fourth Member of Shahejie Formation in the Bonan Sub-Sag

The early Paleogene experiences a prolonged global hyperthermal period. The Lower Submember of the Fourth Member of Shahejie Formation (Es4x) of early Paleogene deposits a set of unique red sequence with influences of global hyperthermal events. Many researches focus on paleoclimate reconstruction of global hyperthermal period. However, few researches concern sequence architecture and sedimentary response in this extreme climate background. As the sequence architecture and sedimentary response record the paleoclimate, the character and origin of them can provide signals to reconstruct paleoclimate. Thus, this research investigates paleoclimate, character and origin of sequence architecture to reveal inter relationships and provide basis for paleoclimate reconstruction. The climate evolution and its sediment supply responses controlled the development of sequence architecture and reconstructed the different sedimentary responses. The periodic evolution of climate and sediment supply response results in the T-R cycle and sand body enrichment in the TST stage. The sand bodies of the TST stage concentrate in the LTST stage as frequency and amplitude of fluctuations are higher. The LTST stage developed large scale sand bodies with longest distance transportation in. Subsequently, the drier and stable climate continues to decreases sediment supply during the RST stage. Sand bodies shrunk to the edge of Sub-sag.