This is the general name for the mineral "halite" with NaCl as the chemical formula. You might know this element as table salt. It can possess impurities of sylvite (KCl) and gypsum (CaSO4) but it is very erratic to discover potassium sulfate as a mineral, though occasionally polyhalite (K2Ca2Mg(SO4)4.2H2O) is got associated with rock salt deposits.
It is typically made by the evaporation of salty water (like sea water) that comprises dissolved Na+ and Cl- ions.
One gets rock salt deposits in inland marginal seas, dry lake beds, and surrounded bays and estuaries in dry regions of the globe. At several times in the geologic time, very big bodies of water (like the Mediterranean Sea and ancient ocean that was located where now is the Atlantic Ocean) also evaporated and created huge deposits of rock salt. Such deposits were later suppressed by marine sediments, but as halite is less thick than the substances that make up the superimposing sediments, the salt beds frequently "punched up" via the sediments to make dome-like edifices. These are now typically buried by extra sediments.Uses:
- Table salt is vital for human lifespan. A large quantity of the commercially calcined rock salt is made for human intake. Rock salt is also useful to road beds in cold weathers to help decrease the freezing point of water on the highway, thereby letting it to not freeze-over at even 0 deg. C
- Further, the creation of Rock Salt deposits from the globe’s oceans is the chief technique via which the Oceans can control their NaCl composition, thus not becoming "excessively" salty.
- Salt creations are also vital in the rock record as they make one of the most vital "deceptions" for petroleum in the crust. Geologists frequently use a diversity of methods to try and find salt domes in the subsurface while they are discovering for new gas and oil resources.