New data on the occurrence of K-feldspathization in the Milin Kamak deposit, Breznik Western Srednogorie

This study presents new findings on K-feldspathization in the Upper Cretaceous volcanic rocks of the Breznik paleovolcano, particulary in the eastern and central areas of the deposit Milin Kamak deposit. The zones of K-feldspathization are identified within propylitic altered andesites and andesite breccias. Notably, the spatial position of these zones aligns with later near-faults developed sericite, argillic, and advanced argillic alterations. Our results indicate the presence of atypical K-feldspathization at depth, characterized by a lack of the typical for potassic alteration mineral assemblage. These results suggest the potential for a copper porphyry-type deposit at depth, supporting the hypotheses proposed by previous researchers.