Source‐to‐sink systems in the Turpan Basin throughout the Jurassic: Constraints from detrital zircon geochronology

Abstract

Source‐to‐sink system studies in oil fields are especially important for optimizing the favourable oil‐gas areas; however, this basin‐mountain interaction process is particularly complicated in intermontane basins. In this study, detrital zircon U–Pb dating of 8 new and 3 published samples from throughout the Jurassic in the central Turpan Basin (TB) are combined with collected heavy mineral data to investigate the evolution of the source‐to‐sink system and reconstruct the filling process of this intermontane basin from the Lower to Upper Jurassic. Based on the detrital zircon ages and heavy mineral assemblage, the filling rocks mainly weathered from Mesozoic, Palaeozoic and Precambrian volcanic and metamorphic rocks in the Tian Shan (TS) area, and the source‐to‐sink systems in the basin show a clear alteration corresponding to the uplift of the surrounding mountains during the Jurassic. In the Lower Jurassic, the uplifted central and northern TS was the main provenance and shed the most source rocks northward, and the gentle positive relief of the Bogda Mountains (BM), the northern boundary of the TB, was a secondary provenance and provided limited material to the northern area. In the early Middle Jurassic, these provenances did not alter much, but in the later Middle Jurassic, uplift of the western BM began and provided some extreme new source rocks with detrital zircon ages of approximately 159–172 Ma. In the Upper Jurassic, the considerably uplifted BM became the main provenance, while the still gently uplifted central and northern TS became the secondary provenance.