Climatic impact on the reef biota in the Cisuralian and Guadalupian (Permian), East European Platform

Abstract

AbstractAs important components of extinct as well as modern reefs, the measurement of changes in the composition of reef biota is crucial in order to evaluate the influence of extrinsic factors on the marine communities. The dramatic abiotic changes in the eastern and northern Pangea was mirrored by a gradual transition from a photozoan to a heterozoan association and the appearance of cool- (temperate-) water carbonates both in reef and carbonate ramp environments. Analyses of large skeletal and microbiotic components as well as microfacies succession were used for detailed explanation of reef structure, especially for lesser-known heterozoan skeletal mounds. The youngest skeletal mounds are recognized in the Roadian. The stable isotope data demonstrated a negative oxygen shift between latest Sakmarian and late early Artinskian coinciding with the end of P2 glaciation. The multiplicative nature of the event included the series of successive changes of extrinsic factors such as ice melting in interglacial episodes, eustatic ocean level rise, change of oceanic circulation and decrease of water temperature. The late Artinskian and subsequent Kungurian climatic impacts in the Northern Hemisphere were irreversible for the photozoan biota and prevented its further development. Roadian (Guadalupian) bryonoderm extended skeletal mounds developed in rather warm-water environments.