Transformation of aragonite-dominated lime muds to microcrystalline limestones

Scanning electron microscopy of textures in several well-lithified Pleistocene "micrites" from South Florida and the Bahamas. The dominance of aragonite in precursor muds is supported by the surprising presence of abundant aragonite relics in the neomorphic calcite crystals. One-step neomorphic process of calcitization. Both early calcitization and concurrent early meteoric cementation were significant in producing the Florida-Bahamas "micrites" studied, which have low porosities similar to those found in most ancient fine-grained limestones. These low porosities, despite the absence of significant overburden, indicate that major porosity reduction without compaction can occur in calcitized aragonite-dominated mud.--Modified journal abstract.