The solidity and porosity of calcium carbonate rocks are of great interest in fields such as reservoir evaluation, groundwater flow, and civil engineering. Micritization (an early diagenetic process converting carbonate shells and skeletons into micro-grained carbonate) affects these rocks characteristics, though its exact mechanisms are poorly understood. The coastal environments of Abu Dhabi provide “natural laboratories” to study micritization, as they resemble the low angle calcium carbonate ramps that were widespread in epeiric seas during the geological past. In this project we examine calcium carbonate muds and correlating porewater from a variety of depositional environments such as mangroves, tidal channels, sabkhas, and offshore locations to better understand micritization. To tackle this problem, we are employing sedimentological, mineralogical and various geochemical methodologies. Preliminary results show that most of the calcium carbonate mud is composed of low-magnesium calcite, with little to no aragonite. This finding contrasts with other studies on calcium carbonate ramps in which the carbonate mud is comprised of high-magnesium calcite. Micritization increases with depth, particularly in tidal channels, and is associated with physical erosion by endolithic fauna. Crystal structures in the sabkhas indicate that chemical precipitation is more prevalent there. The porewater in all sampled environments shows a distinct DIC to alkalinity slope of 1, suggesting that chemical processes such as calcium carbonate precipitation/dissolution in an open system, sulphate reduction/sulphide oxidation etc., are occurring alongside the physical boring activity. Mass balance and thermodynamic simulations are conducted to identify and quantify the possible geochemical processes.