HOME
TheInfoList



250px, Carbonate ooids_on_the_surface_of_a_limestone;_Carmel_Formation.html" ;"title="limestone.html" ;"title="ooids on the surface of a limestone">ooids on the surface of a limestone; Carmel Formation">limestone.html" ;"title="ooids on the surface of a limestone">ooids on the surface of a limestone; Carmel Formation (Middle Jurassic) of southern Utah, USA. Largest is 1.0 mm in diameter. Carbonate rocks are a class of sedimentary rocks composed primarily of carbonate minerals. The two major types are limestone, which is composed of
calcite Image:Calcite.png, 235px, Crystal structure of calcite Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). The Mohs scale of mineral hardness, based on Scr ...

calcite
or
aragonite Aragonite is a carbonate mineral, one of the three most common naturally occurring polymorphism (materials science), crystal forms of calcium carbonate, (the other forms being the minerals calcite and vaterite). It is formed by biological and phy ...

aragonite
(different crystal forms of CaCO3), and dolomite rock (also known as dolostone), which is composed of mineral dolomite (CaMg(CO3)2). Calcite can be either dissolved by
groundwater Groundwater is the water Water is an Inorganic compound, inorganic, Transparency and translucency, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hyd ...
or precipitated by groundwater, depending on several factors including the water temperature, pH, and dissolved ion concentrations. Calcite exhibits an unusual characteristic called retrograde solubility in which it becomes less soluble in water as the temperature increases. When conditions are right for precipitation, calcite forms mineral coatings that cement the existing rock grains together or it can fill fractures.
Karst topography Karst is a topography formed from the dissolution of soluble rocks such as limestone Limestone is a common type of carbonate rock, carbonate sedimentary rock. It is composed mostly of the minerals calcite and aragonite, which are differe ...
and
cave A cave or cavern is a natural void in the ground, specifically a space large enough for a human to enter. Caves often form by the weathering Weathering is the breaking down of rocks, soil Soil (often stylized as SOiL) is an American rock b ...
s develop in carbonate rocks because of their
solubility Solubility is the property of a solid, liquid or gaseous chemical substance called ''solution, solute'' to dissolve in a solid, liquid or gaseous solvent. The solubility of a substance fundamentally depends on the Physical property, physical an ...
in dilute acidic groundwater. Cooling groundwater or mixing of different groundwaters will also create conditions suitable for
cave A cave or cavern is a natural void in the ground, specifically a space large enough for a human to enter. Caves often form by the weathering Weathering is the breaking down of rocks, soil Soil (often stylized as SOiL) is an American rock b ...
formation. Marble is the metamorphic rock, metamorphic carbonate rock. Rare igneous rock, igneous carbonate rocks exist as Intrusive rock, intrusive carbonatites and even rarer volcanic carbonate lava.


See also

*Dunham classification *Folk classification *Sinkhole Sedimentary rocks Carbonate minerals {{Petrology-stub