FORAMINIFERA FROM THE OXFORD DEPOSITS OF THE CRIMEAN MOUNTAINS

Abstract

This study is devoted to the paleontological description of a group of microorganisms– foraminifera–that are of paramount importance for stratigraphy and correlation, as found in Upper Jurassic (Oxfordian) deposits of the Mountainous Crimea. Descriptions and illustrations of 11 foraminifer species are provided, namely the zonally distributed Globuligerina oxfordiana Grigelis, the characteristic Epistomina nemunensis Grigelis and E. mosquensis Uhlig, as well as the boreal species Ammodiscus cf. uglicus ehremeevae Dain, Recurvoides scherkalyensis Levina, Lenticulina cf. prussica Grigelis, Lenticulina cf. paracultrata Grigelis, Lenticulina tymрana Grigelis, and Lenticulina cf. nordformis Putrja et Romanova, which were discovered for the first time in the study area. The described species belong to six genera – Ammodiscus, Recurvoides, Epistomina, Globuligerina, Lenticulina, and Pseudonodosaria – and six families – Ammodiscidae, Ammosphaeroidinidae, Epistominidae, Globuligerinidae, Vaginulinidae, and Nodosariidae; and six orders – Spirillinida, Lituolida, Robertinida, Rotaliida, Vaginulinida, and Nodosariida. A morphological description of the shell has been provided for each foraminifer species. The stratigraphic and lateral distribution of the foraminifer species is indicated, and the deposits and sections of the Mountainous Crimea in which they are found are specified. These species have been identified in the Sudak (upper part), Mandzhil (lower part), and Yailin (lower part) formations of the Mountainous Crimea, which consist of clays, marls, and reef and biogenic deposits. The paper contains images of the aforementioned foraminifer species, which were obtained using a JSM–6490LV scanning electron microscope (JEOL Ltd., Japan). The results of the study have practical significance and can be used for further research and to enhance the objectivity of biostratigraphic and paleogeographic interpretations.