ABSTRACT

The Wangshi Group faithfully records the Late Cretaceous palaeogeographic environment and tectonic evolution of the East Asian continental margin. Here, we reconstruct a four-stage evolution model of the Late Cretaceous source-to-sink system in the northern Jiaolai Basin by multiproxy provenance methods. With statistical and visualization analyses of multiple results and comparisons to the characteristics of potential source regions, the results strongly suggest that (1) the Linjiazhuang Formation (Fm) was mainly sourced from the Qingshan Group volcanic rocks; (2) during the deposition of the Xingezhuang Fm, the Sulu orogenic belt south of the basin was rapidly uplifted and replaced the Qingshan Group volcanic rocks as the primary source area for the basin; (3) during the deposition of the Hongtuya Fm, the tectonic activity on the southern side of the basin weakened, and the Jiaobei area and Qingshan Group volcanic rocks again became primary sources for the basin; and (4) the Jingangkou Fm was sourced mainly from the Jiaobei terrane instead of the Qingshan Group volcanic rocks. The significant change in the main source region of this source-to-sink system during the deposition of the Xingezhuang Fm, from the Jiaobei terrane to the north to the Sulu orogenic belt to the south, suggests that the Sulu orogenic belt experienced rapid uplift in the early Late Cretaceous. The NNW subduction of the western Pacific Plate during the Late Cretaceous may have led to N-S extension in the East Asian continental margin, controlling the deposition of the Wangshi Group in the Jiaolai Basin and inducing the rapid uplift of the Sulu orogenic belt in the early Late Cretaceous.