Stratigraphy and regional development of the mid-Cretaceous (Upper Albian through Coniacian) of the Mangyshlak Mountains, Western Kazakhstan

Abstract

Dynamic stratigraphy and evolution of the Upper Albian through Coniacian of the Mangyshlak Mountains (Western Kazakhstan) is presented. The basic description, fossil content, and stratigraphic-sedimentary interpretation of selected sections covering the whole territory of the Central Mangyshlak Anticlinorium and the Tumgatchi Anticline are provided. From NW to SE the following sections are studied: Shakh-Bogota, Sulu-Kapy, Shyrkala- Airakty, Kush, Koksyrtau-Aksyrtau, Azbirektoy, and Besakty. With the exception of the Upper Albian the similarity of the fossil content permitted the application of the standard European zonation, including some of the bio-events (A. plenus, C. waltersdorfensis, C. brongniarti, and M. striatoconcentricus) of pan-European significance. The successive stages of the sedimentary development clearly show the dependence of the evolution of the area on the eustatic changes and the related paleogeography with only minor effects of the local tectonics. The studied macrofaunal elements (ammonites, belemnites, echinoids, and inoceramids) are invariably Boreal members of the North European Province.