Abstract:

By using typical seismic interpretation results,this paper focuses on a discussion of the development characteristics of the Eopaleozoic inversion structures in the Tazhong uplift and an analysis of their petroleum geological significance.The basement normal faults that were developed during the Sinian to the Early-Middle Ordovician controlled the later structural deformation styles,resulting in two inversion structural styles in the Tazhong uplift.The azimuth of the pre-exiting fault with larger dip angle might not be favorable for its further inversion and forced the inversion to the adjacent faults.The early faults might then serve as stress concentration point for later thrust faults,such as the Tazhong-Ⅱ fault belt and the Tazhong-10 fault belt.Or,they might be buckled by later compressional structures,such as the Tazhong-Ⅰfault belt.It is suggested that an inversion structure contributes in its early stage to hydrocarbon accumulation and forms in its later stage inverted anticlines with different amplitudes that are favorable traps for hydrocarbon accumulation.

Key words: inversion structure, geological model, significance of petroleum geology, Eopaleozoic, Tazhong Uplift