Discovery of hydrothermal venting community at the base of Cambrian barite in Guizhou Province, Western China: Implication for the Cambrian biological explosion

Abstract

The barite deposit in the Niutitang Formation of Lower Cambrian, in Tianzhu County, Guizhou Province, western China, is a super-large barite deposit with about 2 × 109 tons of reserves. Mineral, petrological and geochemical studies reveal that this barite deposit belongs to a hydrothermal sedimentary deposit. Microscopic observations indicate that a lot of algae, sponge spicules and tube-type fossils are well-preserved in this barite section, and moreover, those fossils share most characteristics of the deep-sea hydrothermal venting community in the modern Pacific. We suggest that the hydrothermal venting community was thriving in hydrothermal vent in early Cambrian, and it is of great significance for elucidating the geological background of the “Cambrian explosion”.