Permian Cyanobacterial Blooms Resulted in Enrichment of Organic Matter in the Lucaogou Formation in the Junggar Basin, NW China

The Permian Lucaogou Formation in the Junggar Basin, NW China is target layer for shale oil exploration, but its hydrocarbon precursors have remained focus of debate. In this study, we investigated source rocks throughout Well J10025 by conducting detailed petrological, paleontological, and geochemical analyses purpose revealing occurrence cyanobacterial blooms as specific events upper Formation. morphological characteristics microfossils signatures microfossil-bearing layers support a biological affinity with Microcystis, kind cyanobacteria. Microcystis observed colonial forms embedded are great abundance, indicating presence blooms. They were further evidenced cyanobacteria-derived biomarkers including low terrestrial/aquatic ratio, high 2α-methylhopane index values, abundance 7- 8-monomethyl heptadecanes. occurred semiarid brackish paleoenvironment anoxic to suboxic water conditions intermittent volcanic eruptions. contributed enrichment organic matter two main ways: directly promoting accumulation algal biomass creating an oxygen-depleted environment better preservation matter. This study adds new record geological occurrences Permian, provides unique insight into generation Jimsar Basin.