LIMESTONE

LIMESTONE, sedimentary rock. It consists mainly of calcite or calcite skeletal residues of organisms, rarely of aragonite. It contains minor impurities of dolomite, quartz, gypsum, and clay minerals. The structure is biomorphic (organogenic), detrital, grained; the texture is massive, layered. The color depends on impurities, more often it is white, yellowish, brown, gray to black. In Bashkortostan L. is widely spread in the Riphean and Paleozoic sediments in which it forms layers and horizons up to hundreds of meters thick. The largest deposits are: Shakhtau, Tratau (Ishimbaysky Raion), Pugachyovskoye (Beloretsky Raion), UluTelyakskoye, Kazayakskoye (Iglinsky Raion), Khudolazovskoye (Baymaksky Raion), Ryskuzhinskoye (Abzelilovsky Raion), Rysayevskoye, Yuldashevskoye (Uchalinsky Raion).