OPHIOLITOCLASTIC BRECCIAS IN THE SECTION OF THE SOYMUL OLISTOSTROME FORMATION

Abstract

Purpose. Investigation .of the composition and features of the formation conditions of the Soymul olistostrome stratum in outcrops along the upper course of the Velyka Ugolka River in the Marmarosh Klippen Zone (Inner Ukrainian Carpathians), which is of important theoretical importance for the reproduction of the paleogeography of the basin and its tectonic history. Methodology. In this work there traditional structural-geological methods of field large-scale geomapping were used. Results. During the field work, geological mapping and documentation of the supporting outcrops of the Lower Cretaceous Soimul olistostrome was carried out. The material composition of the rocks in the outcrops was studied, the conditions of occurrence of olistoliths and matrix of the mixtites were investigated. A model of the formation of the Lower Cretaceous Soimul Formation is proposed Scientific novelty. For the first time, specific formations – ophiolithoclast breccias, several types of which are distinguished by the composition of fragments and cement – have been described in the outcrops among scattered fragments of ophiolitic assasia. Practical significance. In detailed geological mapping, the display of thrust and associated mixtite complexes (melanges and olistostomes) is a necessary condition for the reliability and conditionality of geological maps.The improvement of the theoretical and scientific-methodical basis of large-scale mapping of mixtites is also important for the identification of new tectonic criteria for the search for minerals, the forecast of dangerous geological processes, and geostable construction. In addition, the studied section, in our opinion, is a unique geotourism object of the Ukrainian Carpathians. Key words: accretion prism, olistostrome formation, ophiolite association, ophioliclast breccias, ophiocalcite.