YE Yuan-mou¹, FU Yong^{1, 2*}, ZHOU Ke-lin¹, ZOU Niu-niu¹, LONG Ke-shu¹, YAN Shuang¹, CHEN Rui¹

（1. College of Resource and Environment of Guizhou University, Guiyang 550025,China;
2. Institute of Mineral Resource，Chinese Academy of Geological Sciences, Beijing 100037,China）

Abstract: A layer of claystone is widely distributed at the bottom of the Permian Longtan Formation in Western Guizhou. It is commonly found in the Yangtze Platform in South China. It is a marker layer of the Permian Guadalupian-Lupingian (G-L) boundary. Studies on provenance of this claystone are of great significance for inverting geotectonic background. In this paper, we have carried out  mineralogical and geochemical studies of the claystone samples that were collected from the G-L boundary at the Nayong and Zunyi sections in western Guizhou. The X-ray diffraction (XRD) data reflect that the claystone was formed through a process of weathering, transport, and sedimentation, with its material sourced from the Emeishan basalt. The geochemical characteristics indicate that the claystone is characterized with the enrichment of high field strength elements (HFSE) and rare earth elements (REE), more enriched LREE  than HREE,  obviously negative Eu anomalies, and slightly negative Ce anomalies, suggesting that the claystone inherited the element association characteristics of the Emeishan basalt. Therefore, it is believed that the G-L boundary claystone at the bottom of the Permian Longtan Formation in western Guizhou was formed through a process of  weathering, transport, and sedimentation by the material sourced from the weathered Emeishan basalt.

Keywords: claystone; geochemistry; provenance analysis; Guadalupian-Lupingian boundary; Permian system; Western Guizhou