Mesozoic Tectonic Setting and Evolution in Kuqa Depression of the Tarim Basin: A Study of Detrital Zircons and Geochemistry

Kuqa Depression is an important oil-bearing tectonic unit in the Tarim Basin, and the Mesozoic tectonic setting is of great significance for hydrocarbon exploration in the deep-seated strata of the depression. In this paper, the Mesozoic tectonic setting and evolution processes of Kuqa Depression have been studied by using petrology, seismic interpretation, zircon chronology, and geochemistry methods, combined with the analysis of rock properties and age composition of potential provenance areas. The results show that the zircon ages of the sandstones of Triassic Taliqike Formation range from 251 to 2816 Ma, the zircon ages of the sandstones from the Jurassic Yangxia and Ahe formations range from 241 to 2600 Ma, and most of the zircon ages are concentrated in 241–485 Ma. The Mesozoic Triassic and Jurassic strata in the Kuqa Depression are mainly derived from the Yili-Central Tianshan orogenic belt and the Southern Tianshan orogenic belt, and the tectonic background is the passive continental margin. The main provenance of the Cretaceous Kuqa Depression is Southern Tianshan. In the Mesozoic, the provenance of the Kuqa Depression has changed significantly, and there is a trend of strengthening tectonic activity, which is mainly controlled by the interaction between the Central Tianshan and South Tianshan terranes and the Tarim plate. This paper provides a new idea for the tectonic evolution of the Kuqa Depression during the Mesozoic, which will be useful in exploring hydrocarbon accumulations in deep-seated strata.