Fabric-Selective Diagenesis in the Late Pleistocene Miami Limestone

Abstract

ABSTRACT The Miami Limestone is a late Pleistocene ooid sand body which has undergone 130,000 years of meteoric diagenesis. The resultant limestone has a generally high, but variable (15-60%) porosity which is indirectly related to the amount of primary aragonite remaining in the limestone (0-45%). The predominant textural theme in porosity development is the role of the primary sediment fabric, which controls early cementation and porosity development on the scale of individual grains and sedimentary structures and is still influential during late development of channel and cavernous porosity. The porosity development within the Miami Limestone reflects a change from an early system wherein fabric-selective diagenesis occurred primarily as a function of the ability of the sediment to retain pore water to a system wherein the cemented sediments channelize water flow and effectively isolate portions of metastable (aragonitic) limestone from meteoric waters.