Peculiarities of the formation of the Zhailma volcano-tectonic deep

Abstract

Purpose. Studying the features of the Zhailma volcano-tectonic depression formation, as well as the principles and factors affecting this structure’s ore formation. Methodology. Analysis of the results of isotope dating of rocks, critical analysis of literature and fund materials, analysis of the genesis and specificity of the Zhailma structure mineralization, features of the volcano-tectonic depression formation. Findings. The Zhailma graben syncline formation is associated with subsidence after ejections of significant masses of acidic magmatic material from stratovolcanoes concentrated on the Zhailma structure. The initiation and development of the graben-syncline is closely related to the processes of tectonomagmatic evolution of the Devonian volcano-plutonic belt. Originality. The search model for stratiform deposits of the Atasu type has been revised, taking into account the original theory of the volcano-tectonic origin of the structure, formed at the final stages of the formation and development of the Devonian volcano-plutonic belt. The genesis of the Atasu-type deposits is considered as sedimentary-hydrothermal one, associated with the processes of diagenesis and catagenesis occurring within sedimentary basins. The presence of two large volcanoes on the northern side of the caldera structure was substantiated: North Zhairem and Ustanynzhal. Practical value. It is recommended to carry out predictive metallogenic and, accordingly, prospecting work for deposits of the Atasu type within the graben-synclines of the Sarysu-Teniz segment of the Devonian volcanic belt, where such deposits of ferromanganese ores as Tur, Bogach and Karaadyr are already being developed in the Aydagarly graben-syncline.