Ore and ore-silicate microspheres in South Timan Riphean sandstones.

Nikulova N. Yu., Burtsev I. N., Filippov V. N., Myandin A. S.

Zapiski RMO (Proceedings of the Russian Mineralogical Society). 2018. V. 147. N 2. P. 35-44

https://doi.org/10.30695/zrmo/2018.1472.02

Full text is available on eLIBRARY.RU

Language: Russian

Abstract

Ore and ore-silicate microspherules have been discovered while researches of Riphean metaterrigenous rocks of the South Timan. There are described their morphological features, structure and chemical composition. Some microspheres have the complex internal structure—they contain a combination of negative and positive forms. Cavities inside these grains have the shape of curved cones, and it is supposed that they have the pyroclastic origin. It means they were formed when microbubbles of volcanic gas expanded, as a result of the rapid decrease of pressure while the gas-dust cloud released. Probably the studied microspheres indicate the magmatic activity accompanying accumulation of the sediment.

Key words: microspheres, surface sculpture, magnetite, sandstone.