Affiliation:
1. Institute of Geology - Subdivision of the Ufa Federal Research Centre of the Russian Academy of Sciences
Abstract
The subject of research is the petrography of sandstones and siltstones laminae 2–12 mm thick, occurring among the cherts in the lower part of the Iltibanovo Formation. 7 samples taken from the northern and southern ends of the dam of the Iltibanovsky reservoir in the Uchalinsky district of the Republic of Bashkortostan were studied.
The petrographic study of the laminae showed that they contain euhedral crystals and angular fragments of pyroxenes and plagioclases; thin elongated plagioclase crystals; shapeless pyroclasts composed of chlorite or felsite mass, which were originally fragments of volcanic glass. These findings indicate synsedimentary (Lochkovian or Silurian) explosive volcanism.