Prospecting efforts to located Au mineralization within the Altai-Sayan fold area (ASFA) over previous decades have revealed that Devonian epithermal Au-Ag mineralization is more widespread than previously recognized. The preservation of this type of mineralization in Paleozoic rocks offers new prospects for the exploration of Au-Ag deposits in the underexplored region of Gornaya Shoria. The Kalarskoe epithermal Au-Ag occurrence represents Devonian epithermal mineralization within the Kaburchak cluster, Gornaya Shoria, Russia. This occurrence is confined to zones of argillic alteration that were superimposed on previously formed propylites. The argillic-altered rocks host quartz-sulfide veinlet zones. The mineralization of the Kalarskoe site is characterized by a high abundance of sulfide minerals: commonly, 5%–10%; often, up to 20%; and in some cases, up to 60%–70%. The ore minerals are represented by pyrite, arsenopyrite, sphalerite, galena, chalcopyrite, fahlores, native Au, and electrum, as well as by the sulfosalts Pb, Bi, Ag, Cu, and the tellurides of Au, Ag, and Pb. Based on mineralogical observations, at least four generations of sulfide mineral formations are distinguished within the ore occurrence. The mineralization of the Kalarskoe ore occurrence may be assigned to the intermediate sulfidation (IS) type. The results of the (U,Th)-He dating of pyrite from the pyrite-arsenopyrite massive body (pyr-3 and 4) revealed the protracted history of the mineralization in the intervals from ~399 to ~371 Ma. The obtained results substantially enhance the prospecting models for the exploration of epithermal Au-Ag deposits in the western part of the Altai-Sayan fold area (ASFA).

The main techniques used for gas extraction from solid geological samples for geochronological studies are their thermal destruction either in an isothermal mode, for example in a double vacuum furnace, or under the action of laser radiation. Approaches based on the use of laser technologies are more express and have a low-background. The article describes an original high-vacuum experimental setup based on an ytterbium fiber optic laser for gas extraction from milligram samples of rocks and minerals in a scanning mode. In the proposed configuration, a static vacuum of 10^–8 Torr can be achieved in the high vacuum laser cell. Heating of individual mineral grains to a temperature of over 1800°C is ensured. Using the example of the international standard for (U,Th)–He dating—Durango apatite—it is demonstrated that the laser installation ensures complete extraction of radiogenic helium from the mineral and can be used for isotope-geochronological studies.