Depositional environment of the Lower Cretaceous Muling Formation of the Laoheishan Basin (NE China): Implications from geochemical and petrological analyses

The Laoheishan Basin located in northeastern China is filled with non-marine coal- and “oil shale” (oil-prone mudstone) sediments of the Lower Cretaceous Muling Formation. Based on petrological, mineralogical and geochemical methods, the depositional environment during organic matter (OM) accumulation is investigated for the first time. The coal is subbituminous in rank. Petrological and bulk geochemical data indicate sapropelic coal, deposited...