Limestone can be formed as a result of evaporation, as is the case for stalactites and stalagmites in caves, or through the accumulation of calcium carbonate in marine environments. Limestone is either a biological or a chemical sedimentary rock, depending on its method of formation.Continue Reading
Limestone formations created through evaporation are chemical sedimentary rocks, also known as travertine. They are formed when droplets containing calcium carbonate leak through cave ceilings and evaporate. As each evaporated droplet leaves behind a small amount of calcium carbonate, a stalactite forms. If droplets fall to the floor and then evaporate, a stalagmite extends upward as the calcium carbonate starts to pile up. Many caves are filled with these characteristic limestone teeth.
Biological sedimentary limestone forms most often in warm, shallow marine waters in areas between 30 degrees latitude north and 30 degrees latitude south. This type of limestone is formed as marine organisms with calcium carbonate shells and skeletons die and accumulate layer by layer. Eventually, with extensive pressure and time, that calcium carbonate sediment hardens into limestone. These types of rocks often have fossils present in them. A less common method of limestone formation is through the direct accretion of calcium carbonate from either salt or fresh water.Learn more about Geology
Some good, natural sources of saltpeter are caves and sheltered areas, deserts and lake beds. Saltpeter, also known as potassium nitrate, is also found in soil and occasionally in high-nitrite vegetables. As of November 2015, potassium nitrate is usually manufactured in laboratories and rarely found from natural sources.Full Answer >
Most caves are made in a specific landscape known as karst. Gypsum rocks, limestone and dolomite are dissolved by acidic rain to form caves. It takes more than 100,000 years for most caves to become large enough to accommodate humans. Many caves exist in a system of interconnected underground pathways.Full Answer >
The exact composition of sand varies from region to region, but in most cases it is a mixture of silicon dioxide, weathered rocks and local minerals, calcium carbonate from reefs, and the remains of microscopic sea creatures. The action of the ocean waves or wind grinds this material together until all that remains are tiny fragments.Full Answer >
Crushing different minerals creates different types of limes, two of which are agricultural lime (calcium carbonate) and magnesite (magnesium carbonate). Other limes, such as burnt lime (calcium oxide), hydrated lime (calcium hydroxide) and burnt magnesite (magnesium oxide), are the products of additional treatment, according to the NSW DPI.Full Answer >