Destruction mechanism of organic matter enrichment controlled by tectonism in the lower Silurian organic-rich marine mudstone in the western South China Block

Abstract

This destruction mechanism of organic matter enrichment plays an important role in improving the mudstone sedimentary structure system. For the lower Silurian marine mudstone in the western South China Block, the destruction mechanism of organic matter enrichment is unclear, with previous studies ignoring the control from paleogeography and spatial differences. Lamination is a typical sedimentary structure in mudstone and different types of lamination in mudstones can reflect a range of depositional environments. Lenticular lamination, composed of arranged lenses of variable composition, is a common type of lamination in marine mudstone and mainly occurs in organic-lean mudstone. The origin of lenticular lamination remains controversial, and a multidisciplinary approach is needed that integrates sedimentology, petrography, and paleogeography. The main objectives of this approach are to (1) interpret the formation mechanism of lenticular laminations in the Longmaxi marine mudstone, and (2) discuss the significance of lenticular lamination to organic matter destruction. The results not only allow for a complete understanding of the destruction mechanisms of the Silurian marine mudstones but also provide new insights into the sedimentary processes of marine mudstone.