Lithification of Miocene lacustrine carbonates. Madrid basin: Implications for understanding the diagencsis of calcite-dominated marine carbonates?

As a possible model for lacustrine carbonate diagenesls, and as a guide for understanding calcitedominated marine limestones, a range of indurated Miocene limestones from the Madrid Basin were studied. Despite very shallow burial and a calcitic precursor, the micrites and bioclasts underwent two phases of recrystallization. Initially the muds and bioclasts were recrystallized to a microporous uniform luminiscent micrite with complete loss of any primary fabric, possibly in a shallow suboxic phreatic zone. Subsequent exposure and karstificatión (probably in the early Pliocene) resulted in microspar/pseudospar formation causing induration. Low Mg calcite muds appear particularly susceptible to recrystallizatio