STAGE SUBDIVISION OF THE PALEOCENE

Abstract

In the southwestern Crimean Mountains, the lower Paleocene deposits (from 40-45 to 80-85 m thick) are perfectly exposed and fully characterized by macro- and microfossils. Two parts of the sequence are sharply different in paleontological aspect: the Danian bryozoan and foraminiferal limestones contain Crania and Echinocorys, and the Montain organogenic-detrital and foraminiferal limestones bear peculiar molluscan fauna and Echinanthus. According to parametric observations in the southwestern Crimean Mountains and some other distribution areas of the lower Paleocene carbonate rocks, the thickness of the Danian deposits is of the same order, but slightly greater than that of the Montian rocks. Inadequacy of the traditional stratotypes of the Paleocene stages (indistinct contacts with underlying and overlying deposits, hiatuses, unclear biostratigraphy, and others) can be compensated to some degree by other reference sections of the European paleobiogeographic realm. Sections exposed at the Churyuksu (the Bakhchisarai section), Kacha, and Bel'bek rivers (the Bel'bek section) of the southwestern Crimean Mountains are proposed as supplementary for the reference section. The stratotype section for a vast geological region should be composed of several reference sections to make stratigraphic investigations most effective. Based on the historical-geological data, the Paleocene deposits are subdivided into the lower and upper subseries. The lower subseries comprises the Danian and Montian stages.