Origin and evolution of intrusive rocks of the Main Ural Fault based on petrogeochemistry and thermodynamic modelling (Balbuk areal, Southern Urals)

The study focuses on intrusive rocks of the Main Ural Fault zone. This article provides a novel description of their petrogeochemical features. It has been established that diorites, diorite-porphyrites, monzodiorites, and monzonite-porphyry are products of a single melt. The following methods are used for petrological and geochemical characterization: X-ray fluorescence analysis (XRF), inductively coupled plasma mass spectrometry (ICP-MS), and numerical modeling using the Rhyolite-Melts software package. The studied rocks were formed by melting of metasomatized lithospheric mantle, with amphibole fractionation being the primary subsequent petrogenetic process. Our studies have established that the intrusive formations of the Balbuk area, developed within the Miass urban district, formed 350—335 million years ago and represent monzonitoid magmatism in the Magnitogorsk megazone of the Southern Urals during the Visean period. However, they are not genetically related to the gabbro-monzonite-granite Balbuk complex. We assume that the studied intrusive bodies were formed during the collision of the Eastern European continent and the Kazakhstan microcontinent.