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Carbonate depositional environments are dominatly shallow marine, but often also include sediments deposited in peritidal zones, where there is daily or longer emergence, and deep subtidal environments. Less commonly, carbonate deposition can be observed within lakes and around terrestrial hot springs.

Peritidal sediments are deposited within the shoreline area that is subjected to daily or less frequent tidal action, above the subtidal zone (which is permanently below sea level) but which is not permanently emergent.

One of the principle depositional environments on the carbonate platform top and inner ramp is the shallow subtidal environment. Often this area is protected from the open ocean by a constructional barrier or grainstone shoal, and therefore depositional energy levels are reduced. This environment is typically referred to as a lagoon.

Shallow water, subtidal lagoons are usally protected from the open ocean by a constructional barrier or grainstone shoal, and therefore the energy levels are reduced. However, when the barrier has a relatively low topography, then the inner rampor platform top might be subject to higher wave and current energy. This is particularly true on platforms that face the open ocean. In this case, sedimentation is dominated more by wave and current activity, and sediment transportation, than in lower energy, protected lagoons.

Carbonate build-up is a generic term used to describe any organic deposit that forms topography above the sea floor. The composition of carbonate build-ups has changed through time as a function of evolution, and they tend to only occur during periods where organisms with the capacity to build topographic relief occur.

Carbonate platform margin facies associations will form within the high energy margin of a carbonate platform; where facies are constructive then they are responsible for the formation of the shelf break. Platform margin facies are typified by two principal lithofacies associations, both of which are indicative of deposition with a moderate to high energy setting in clear, shallow water:

• Constructive carbonate facies such as mounds, reefs and build-ups
• Grain-dominated, remobilised sediment that might collectively be referred to as a ‘shoal’ but includes sandbars and sand waves.

Carbonate slope facies associations will form immediately offshore of the shelf break on a flat-topped carbonate platform and within mid to outer ramp settings on carbonate ramps. They may also be recognised within intrashelf basins formed on the top of flat-topped (usually epeiric) carbonate platforms. The types of facies that are present will be largely dependant on slope angle.

Carbonate basinal facies associations will form distal to the shelf break of a flat-topped carbonate platform and within outer ramp settings, beneath storm-weather wave base. They may also be recognised within intrashelf basins that form on the top of epeiric platforms.

Carbonate sediments are often interbedded with other rock types, which may provide information on palaeoclimatic conditions and basin evolution. Identification of non carbonate facies can also be critical to reservoir quality and architecture.

Precipitation of evaporite minerals can be intimately related to carbonate sedimentation, particularly where platforms have grown in arid basins. Precipitation of evaporites typically occurs in highly saline seawater that has undergone high levels of evaporation, potentially forming laterally extensive layers and, often, a seal to the reservoir.

Siliciclastic sediments can be intercalated with carbonate sediments on carbonate platforms when the platform is land-attached. Delivery of sediment is usually via fluvial and deltaic systems that become established during a fall in relative sea level and/or hinterland rejuvenation. The palaeoclimate has to be sufficiently humid for these systems to develop. The grain size, sorting and composition of the sediment will be dictated by hinterland topography, climate and drainage.