The Structure and Stratigraphic Position of the Agoi Olistostrome, Northwest Caucasus

Abstract

A sequence of clays and clayey siltstones with olistostrome horizons and olistoplaques of the Upper Cretaceous rocks occur in the coastal section northwest of the mouth of the Agoi River. The rocks of this sequence are mostly gray sandy calcareous clays with rare interlayers of siltstones. The horizons and lenses of olistostromes contain small clasts, large blocks, and olistoplaques of rocks of various ages. The microfauna from matrix and clasts of olistostromes of different horizons of the sequence was sampled and identified. The large blocks and olistoplaques are tectonized with formation of slickensides and cracks, which do not travel beyond the country rocks. The thickness of the sequence is 280 m.