carbonate sedimentology

Carbonate sedimentology focuses on rocks composed primarily of carbonate minerals, mainly calcite (CaCO₃) and dolomite (CaMg[CO₃]₂). These are the most significant nonsiliciclastic sedimentary rocks, often forming in shallow marine environments, particularly in warm, equatorial waters.1

The mineralogy of carbonates is dominated by calcite and dolomite. While ancient rocks are primarily composed of these, modern carbonate sediments often consist of metastable aragonite and magnesium-rich calcite, which recrystallize into calcite during diagenesis. Other carbonate minerals like magnesite, rhodochrosite, and siderite can occur in smaller amounts.1

Dolomite is typically formed through a process called dolomitization, where existing limestone minerals are converted into dolomite. This process can alter the original textures of the rock. Carbonate rocks can transition into siliciclastic rocks as the proportion of terrigenous grains increases. The composition and structures of carbonates offer insights into their depositional environments and paleogeography.12