On heating above 250 �C, the completely anhydrous form called ?-anhydrite or " natural " anhydrite is formed.
32.
A massive anhydrite ( the Nar Member ) separates the K4 from the underlying K5 unit which has poor reservoir qualities.
33.
The calcium sulfate may consist of natural gypsum, anhydrite, or synthetic wastes such as flue-gas desulfurization gypsum.
34.
The volcano is constructed from andesite and dacite containing hornblende and also anhydrite and its pyroclastics are all older than Lascar.
35.
In the Lower Eocene, Basin conditions became restricted, producing an alternating dolomite and anhydrite sequence with a consistent thickness.
36.
The Group is up to 900m thick and comprises red, brown and grey mudstones with beds of halite and anhydrite.
37.
Boracite is typically found in evaporite sequences associated with gypsum, anhydrite, halite, sylvite, carnallite, kainite and hilgardite.
38.
Along its eastern and southern margins the formation grades into the breccia that results from the dissolution of its halite and anhydrite.
39.
The most abundant phenocryst minerals were hornblende and plagioclase, but an unusual phenocryst mineral was also present the calcium sulfate, anhydrite.
40.
The latest Permian deposits in the area of northwestern Europe was characterised by the laying down of thick successions of rocksalt and anhydrite.
