Massive recrystallization of low-Mg calcite at high temperatures in hydrocarbon source rocks: Implications for organic acids as factors in diagenesis

Abstract

We document massive recrystallization of low-Mg calcite lime mudstone source rocks at moderately high temperatures in the Smackover Formation of Mississippi. This process was driven by organic acids produced during kerogen maturation and holds the implications for studies of primary migration of hydrocarbons, secondary porosity generation in reservoirs, and global environmental change. This interpretation is based on contrasting the following petrographic and bulk-rock geochemical characteristics of organic-poor vs. organic-rich lime mudstones: