Rare earth element characteristics of the Permian Lucaogou Formation shale in the Junggar Basin, Northwest China

• Published in: Arabian journal of geosciences Vol. 15; no. 21
• Main Authors: Yin, Jun, Wang, Li, Lin, Haitao, Zhu, Yali
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.11.2022; Springer Nature B.V
• Subjects: Body condition; Carboniferous; Climate; Continental crust; Diagenesis; Earth and Environmental Science; Earth mantle; Earth science; Earth Sciences; Humid climates; Island arcs; Oil shale; Original Paper; Oxygen; Oxygen content; Permian; Rare earth elements; Sedimentary rocks; Shale; Shale gas; Shale oil; Shales; Tectonics; Trace elements; Volcanic rocks; Water bodies; Junggar Basin; Lucaogou Formation; Junggar Basin; REE; Organic-rich shale; Geological significance; Geochemistry; Organic-poor shale
• DOI: 10.1007/s12517-022-10873-1
• ISSN: 1866-7511

The Junggar Basin is a Permian foreland basin. Organic-rich shale is widely developed in the Permian Lucaogou Formation in the southern margins of this basin. However, little research has been done to investigate the rare earth element (REE) features of the Lucaogou Formation shale. In this study, we use elemental methods to analyze the REE features and geological information of the Lucaogou Formation shale. Results suggest that the total REE contents of lower member and upper member of Lucaogou Formation are less than those of the upper continental crust and the North American Shale Composite. The chondrite-normalized and primitive mantle-normalized patterns of the lower member and upper member both suggest similar distribution trend and negative Eu anomaly. The correlations between δCe, δEu, ∑REE, Dy N/ Sm N , and La N/ Sm N indicate that the Lucaogou Formation shale is in the stage of early diagenesis. Source area analysis suggest that the Lucaogou Formation shale mainly derived from the mixture of Carboniferous felsic and basic volcanic rocks. Tectonic background of these areas should belong to the continental island arc. Sedimentary conditions of the lower member were humid climate. Water body conditions were alkaline and salty with low oxygen content. Furthermore, sedimentary conditions of the upper member were dry climate. Water body conditions were acid and fresh with high oxygen content. This study would be of great significance for the evaluation of shale oil and gas in the Lucaogou Formation.