Cenozoic structural characteristics and petroleum geological significance of the Qaidam Basin

Abstract

The Qaidam Basin is a Cenozoic continental basin formed by the subduction and collision between the Indian plate and the Eurasian plate. It is the only large oil- and gas-bearing basin in China on the Qinghai–Tibet Plateau. The Qaidam Basin has recorded the uplift of the plateau with its complete Cenozoic sequences. Therefore, studying the structural characteristics of the Qaidam Basin helps us to understand the uplift of the Qinghai–Tibet Plateau. Studies have shown that the structural activities in the Qaidam Basin were episodic, transformable, and inconsistent, which reflected the characteristics of the uplift of the Qinghai–Tibet Plateau. In general, the structural activities of the Qaidam Basin are divided into three phases, which are characterized by the shifting of structural activities from the south to the north, the west to the east, and from the margin to the hinterland of the basin, respectively. The intensity of the early activity was greater than that of the early basin in both time and space. In conclusion, the uplift of the Qinghai–Tibet Plateau controls the structural and sedimentary characteristics of the basin and ultimately, the hydrocarbon accumulation and distribution of the basin.