REE characteristics and geological significance of mudstones from Wenchang Formation in eastern Yangjiang Sag of Pearl River Mouth Basin

Abstract

The REE in sedimentary rocks have strange chemical stability and can well record the original sedimentary message.In order to explore the material source, tectonic setting and sedimentary environment of the Wenchang Formation in Eastern Yangjiang Sag, the REE geochemical characteristics of Wenchang Formation mudstones from well Y-1 in the study area were systematically analyzed.The results show that the concentrations of REE in mudstones of Wenchang Formation is high, yielding relatively enrichedof LREE, obviouslyEu negative anomaly and weak Cepositive anomaly.The material of Wenchang Formation is mainly source fromgranite with a small amount of sedimentary rocks, and thus the sedimentary source area is likely to be the passive continental margin tectonic setting.TheCeanom and δCe indicate that the water was under reducing conditions, which could provide well preservation conditions for the development of high-quality source rocks. Furthermore, the temporal variations of redox conditions are consistent with the variation trend of TOC of mudstone in Wenchang Formation.

Keywords

• tectonic setting
• sedimentary environment
• rare earth element
• wenchang formation
• eastern yangjiang sag
• pearl river mouth basin