Unique location of hydrothermal biota in the Lower Cambrian sedimentary-volcanogenic complex of the Kyzyl–Tashtyg ore field (Eastern Tuva)

Study of Early Cambrian sedimentary-volcanogenic complexes hosting the Kyzyl–Tashtyg pyrite deposit in Eastern Tuva has revealed cyanobacteria and algae that existed in zones of ore-forming hydrothermal systems similar in characteristics to present-day “black smokers” at ocean bottoms. Along with archaeocyaths and Cyanophyta from the host sedimentary rocks and microfossils from basalt amygdules, various cyanobacteria, monocyatheans, and sponge spicules have been found in ferrosiliceous deposits and metasedimentary rocks. Scanning electron microscopic, mineralogical, and thermobarogeochemical studies helped to reconstruct their hydrothermal environment.