Solutional cave and most abundant solutional caves are located in limestone. Limestone caves are often adorned with calcium carbonate formations produced through slow precipitation. These include flowstones, stalactites, stalagmites, helictites, soda straws, calcite rafts and columns. These secondary mineral deposits in caves are called "speleothems". Limestone dissolves under the action of rainwater and groundwater charged with HCO (carbonic acid) and naturally occurring organic acids. The dissolution process produces a distinctive landform known as "karst", characterized by sinkholes, and underground drainage. Solutional caves in this landform—topography are often called karst caves. Lechuguilla Cave in New Mexico and nearby Carlsbad Cavern are now believed
Calcium cycle layers of shell which over time cement to form limestone. This is the origin of both marine and terrestrial limestone, formed over long periods of time . The concentration of marine calcium depends on the depth of the ocean, as its solubility is altered with pressure. In deep ocean, roughly 1% more calcium is present when compared to surface concentrations. This is due to the solubility of calcium at higher pressure, thus associating higher concentration with increasing depth. The higher pressure stops calcium carbonate precipitation, whilst simultaneously enabling the dissolution of calcium carbonate sediment such as shells. As a result,