| Abstrakt: |
The following alteration types are established in the Gurgulyatski Kamak area: propylite, propylite-argillic(?), sericite and alunite (kaolinite-alunite). The sericitic rocks occur as a separate zone among weakly altered up to propylitic rocks. The mineral composition is represented by: albite, sericite, illite, quartz, zeolites, kaolinite, alunite, carbonates, pyrite, iron oxides, jarosite. The behavior of the petrogenic elements is typical for the Secondary Quartzite Formation (advanced argillic altered rocks) from the Srednogorie Zone. Among the trace elements is notable the presence of Sr with characteristic increased content in such rocks. The altered rocks differ sharply from the host rocks by their increased fracturing. Three main joint systems are observed: 135/65° NE, trending at 350–170°, dipping 65–70° to the west or east and 70–90°, dipping at 40–50° to the south. The established geochemical anomalies of Cu, Pb, Zn, Sn, and Аg are weak, but Au is with increased background content and in single samples reaches 1 ppm. The presence of characteristic rocks for the Secondary Quartzite Formation shows the presence of an epithermal system of high sulphidation type. The development of a porphyry system is quite probable, but its distance and productivity are obscure. The alunite rocks are also prospective as a raw material for the chemical and cement industry. [ABSTRACT FROM AUTHOR] |
