On the possible role of magmatism in the atasu type strathiform mineralization (Central Kazakhstan)

Abstract

Purpose. Studying the geological features of large industrial Atasu type ore objects. Methodology. Critical analysis of literature and stock materials, comparative analysis of geological factors characteristic of stratiform ores, stages and peculiarities of formation depending on the processes of volcanism, analysis of the results of isotope dating of rocks. Findings. Participation of volcanism (magmatism) processes in forming deposits of ferromanganese and barite-polymetallic ores of the Atasu type was minimal. It was expressed only in the development of a dissected pre-Famennian paleorelief favorable for the accumulation of metal-bearing silts and in the development of local hydraulic seals, which made it possible for the metal-bearing waters to circulate. Magmatic formations are protrusions of more ancient pre-Famennian Givetian-Franian volcanic structures. Originality. The pre-ore age of subvolcanic intrusions partially confirmed by the results of determining the absolute age, from the samples taken in the quarry of the Ushkatyn deposit that amounted to 373 4 million years, which corresponds to the middle of the Frasnian stage. The presence of three Atasu type ferromanganese deposits in the amagmatogenic Aidagarly graben-syncline also confirms this hypothesis. The genesis of deposits of the Atasu type is considered as sedimentary-hydrothermal one, associated with the processes of diagenesis and catagenesis. Practical value. Predicting the possibility of finding deposits of the Atasu type in graben-synclines throughout the entire area of the Devonian volcano-plutonic belt.