Petrology and industrial application of main diatomite deposits in the Transuralian region (Russian Federation)

In the middle of the last centuary, large resources of Paleocene–Eocene diatomites were discovered in the Transuralian region. By now, more than 100 near-surface diatomite deposits and potential sites have been identified within the Serov–Shadrinsk lithofacial zone. Despite the large diatomite resources, relatively simple mining–engineering conditions, proximity of some well-known outcrops of diatomite to transportation facilities and large industrial towns, the matter of effective practical application of diatomites from the Transuralian region is still debatable. This work presents results of studying the material composition and textural features of Eocene diatomites of the deposits at Agirish, Irbit, and Kamyshlov, Eocene diatomaceous clays of the Shadrinsk deposit and, for the first time, Paleocene diatomites of the Brusyana deposit. Diatomites of these Transuralian deposits are similar in SiO 2 to other large diatomite deposits of the Russian Federation. They are characterized by thin horizontal lamination and a large microporosity, as well as similar textural peculiarities. Diatomites are mostly composed of well-preserved diatoms (85–95%); the SiO 2 content in some fossils is as high as 98–100%. According to chemical and mineralogical composition, Paleocene diatomites from the Brusyana outcrop are considered as the most “pure” varieties among all Transuralian diatomites. Diatomaceous clays of the Transuralian region are characterized by lower SiO 2 contents, a higher proportion of clay and a low preservation degree of siliceous fossils. The results of analytical studies suggest that Transuralian diatomites can be used as both raw material for production of construction materials and potential raw material for filter materials, catalysts, and sorbents.