PHASE TRANSFORMATIONS OF MUD BRECCIA MINERALS DURING THERMAL METAMORPHISM

Mud breccia is of great interest both from the point of view of explaining the genesis and mechanism of operation of the structures of mud volcanism, and from the point of view of a potentially promising raw material for expanded clay and other building materials. The article is devoted to the study of the mineral composition of the volcanic mud breccia from the Kerch-Taman mud volcanic region by means of four methods: the ultrasonic method; an approach to studying changes in the velocities of elastic waves in plastic rocks and sediments under heating; petrographic analysis of thin sections; and an X-ray diffraction method for studying the phase mineral composition. The applied integrated approach made it possible to obtain qualitative and quantitative data that reveal the process of changing clay matter. Ultrasonic studies made it possible to observe changes in the characteristics of elastic waves when heated. X-ray diffraction analysis made it possible to study mineral associations and phase changes in a substance upon heating. The description of the thin sections made it possible to visualize the transitional stages, to study the lithological and mineral composition. It has been established that the change of clay matter (mud breccia) occurs in several stages – temperature intervals. A comprehensive study of the microstructure of clay rocks (X-ray diffraction analysis and petrographic description of thin sections) made it possible to associate temperature intervals with changes in the microstructure, mineral composition of the rock, and rates of elastic vibrations.

mud breccia, mud volcanism, thermal metamorphism, ultrasonic sounding, X-ray phase analysis, Kerch-Taman mud volcanic region