Reconstructing provenance interaction of multiple sediment sources in continental down-warped lacustrine basins: An example from the Bodong area, Bohai Bay Basin, China

Abstract

Abstract The Neogene Guantao Formation has been proven to be one of the most important reservoirs in the Bohai Bay Basin (BBB), but its sediment provenance, sediment routing and dispersal have remained controversial. In this study, we perform an integrated of detrital zircon geochronology, heavy mineral assemblages and seismic-based analyses of the Guantao Formation to investigate the sediment provenance and reconstruct provenance interaction of multiple sediment sources. Our results show that the detrital zircon (DZ) age spectrums of Guantao Formation display significant spatial differences corresponding to the changing sources. DZ ages from the northern part of the Bodong area display a relatively complex age spectrum and are characterized by a multimodal distribution, indicating sediment contribution from Liaodong uplift (LDU). In contrast to the sediments from LDU, the southern part of the Bodong area was characterized by Yanshanian-dominated unimodal age spectra together with the absence of 170–180 Ma and Triassic age populations suggesting sediments sourced from the Jiaodong uplift (JDU). However, in the central part of the Bodong area, DZ ages exhibit Yanshanian-dominated unimodal age spectra but present 170–180 Ma and Triassic age populations. Combined with seismic-based provenance analysis and heavy mineral ZTR index study demonstrate that both the LDU and JDU have made important provenance contributions to the central part of the Bodong area. Consequently, the provenance intersection area can be trapped by samples sharing similar age signature in the three members (from base to top: NgL, NgM, and NgU) of the Guantao Formation. These results shed light on the spatial and temporal provenance heterogeneity in such dynamic sediment-routing systems. Our findings may serve as a useful reference for reconstructing provenance interaction of multiple sediment sources in other types of petroliferous basins.