Major, trace, and rare earth element geochemistry of black shales from Devonian Sanai Formation in Northwestern Peninsula Malaysia: implications for the depositional environment, provenance, and tectonic setting

In this study major, trace, and rare earth elements (REEs) content of Sanai (SA) shales were determined by XRF-ICP-OES and ICP-MS. These results were used to probe tectonic setting, depositional environment, and provenance and of the SA Formation black shale. These black shales contain an average total organic carbon (TOC) content of 2.68 wt. . Black shales from SA formation were deposited in the active continental margin based on ternary diagrams of La-Th-Sc and Th-Sc-Zr/10. SiO2 is rich in SA shales with avg. 59.5 while Al2O3 is the second most dominant major oxides with avg. 15.8. Major oxides of the Western Peninsula (WP) Malaysia shale and hot shale gas reservoirs from China are also compared for the assessment. Redox element ratios infer deposition of the black shale most likely occurred in oxic to the anoxic environment. SA Formation black shales show a low Sr/Ba (< 0.5) value, indicating low salinity during the deposition. Geochemistry results indicate that the SA black shales seem to have been originated principally from the felsic source rock which might be granite in this case. © Published under licence by IOP Publishing Ltd.