Early Cretaceous sea-level changes and major palaeoclimate events in the Northeastern Peri-Tethys

Abstract

The Early Cretaceous quantitative sea-level curve constructed for the epeiric basin of the Eastern Russian Platform (Northeastern Peri-Tethys) is based on the results of facial analysis and quantitative paleo-depth assessment. The detailed evaluation of the Early Cretaceous sea-level cycles results in recognition of the sea-level and climate changes as controlling factors on depositional environments in the basin. Major climatic events are identified by the comparison between the global and regional sea level curves. “The cold snaps” coincide with simultaneous global and regional sea level lowstands, peak shallowing and the almost complete absence of strata. The Late Berriasian and Late Aptian “cold snaps” were identified in the Eastern Russian Platform. The Lower Aptian bituminous shales are interpreted as being a regional manifestation of the OAE 1a. The forcing mechanism behind this OAE is an abrupt rise in temperature.