Explosive breccia of the Vysokogorsky tin-porphyry deposit: genesis and their role in ore formation, Kavalerovo ore district, Primorye
Detailed geological researches and analytical results made it possible to distinguish two groups of fluid explosive breccias within the Vysokogorsky tin deposit of the Kavalerovo ore district. Brecciation is supposed to be associated with different stages of the geological (geodynamic) evolution and different roles in the ore formation. Earlier breccias (79-69 Ma) altered due to boron metasomatism and following main tin mineralization most probably present the Cretaceous subduction stage. Later breccias (56-51 Ma) are syngenetic with dacite (rhyolite) - porphyry dikes can be of the Paleocene-Eocene transform motion stage. They were formed after sedimentation of the bulk of cassiterite, but prior to the latest quartz-fluorite-carbonate stage of ore formation. According to R. Sillitou’s classification, explosive breccias of the Vysokogorsky deposit can represent a magmatic-hydrothermal genetic type characterized by repeated brecciation and intrusion of small bodies of porphyric rhyolites. Some ore deposits like the studied Vysokogorsky deposit have the pre-ore breccias genetically related with diorite intrusions are injected by intrusion of the intra-ore dioritic porphyrite dikes.