TY - JOUR

T1 - Composition and metal contents of ore-forming fluids of the Kalguty Mo-W(Be) deposit (Gorny Altai)

AU - Borovikov, A. A.

AU - Goverdovskiy, V. A.

AU - Borisenko, A. S.

AU - Bryanskiy, N. V.

AU - Shabalin, S. I.

PY - 2016/4/1

Y1 - 2016/4/1

N2 - Based on results of study of fluid inclusions, we have established the specific fluid regime of formation of the Kalguty Mo-W(Be) deposit (Gorny Altai). Using classical thermobarogeochemistry (cryo- and thermometry) and modern microprobing methods (Raman spectroscopy and LA-ICP-MS), we studied fluid inclusions in quartz of quartz-wolframite veins (ore formation stage I), specific "quartz core" (quartz lens), and pyrite-chalcopyrite-molybdenite paragenesis (ore formation stage II). The results of study show that the quartz-wolframite veins of the Kalguty deposit formed with the participation of reduced W-Sb-bearing fluids with a salt content of up to 5.9 wt.%. Their gas phase consisted of CO2, N2, and CH4. Formation of pyrite-chalcopyrite-molybdenite mineralization involved oxidized hot (530-420 °C) fluids with the average salt content of 9.3 wt.%. Their gas phase was of high density (up to 0.55) and consisted of CO2, N2, and H2S. The pressure of the mineral-forming environment varied from 50 to 25 MPa. The fluids contained Cu, Mo, Bi, and S. The productive greisen-vein Mo-W(Be) mineralization of the Kalguty deposit resulted from the superposition of greisen molybdenite-chalcopyrite mineralization on parageneses of earlier formed quartz-wolframite veins. Oxidized metal-bearing fluids that formed the Mo mineralization of the Kalguty deposit have high contents of S and are geochemical analogs of magmatic metal-bearing ore-forming fluids of the Central Aldan porphyry Cu-Au-Mo deposits, which are genetically related to alkaline massifs. This suggests the significant influence of the mantle source on the formation of the Kalguty rare-metal ore-magmatic system. The same is evidenced from the sulfur isotope composition of chalcopyrite, molybdenite, and pyrite from ore parageneses, falling in the narrow range of δ34S‰ from -1.2 to +2.9 corresponding to the isotope composition of mantle sulfur.

AB - Based on results of study of fluid inclusions, we have established the specific fluid regime of formation of the Kalguty Mo-W(Be) deposit (Gorny Altai). Using classical thermobarogeochemistry (cryo- and thermometry) and modern microprobing methods (Raman spectroscopy and LA-ICP-MS), we studied fluid inclusions in quartz of quartz-wolframite veins (ore formation stage I), specific "quartz core" (quartz lens), and pyrite-chalcopyrite-molybdenite paragenesis (ore formation stage II). The results of study show that the quartz-wolframite veins of the Kalguty deposit formed with the participation of reduced W-Sb-bearing fluids with a salt content of up to 5.9 wt.%. Their gas phase consisted of CO2, N2, and CH4. Formation of pyrite-chalcopyrite-molybdenite mineralization involved oxidized hot (530-420 °C) fluids with the average salt content of 9.3 wt.%. Their gas phase was of high density (up to 0.55) and consisted of CO2, N2, and H2S. The pressure of the mineral-forming environment varied from 50 to 25 MPa. The fluids contained Cu, Mo, Bi, and S. The productive greisen-vein Mo-W(Be) mineralization of the Kalguty deposit resulted from the superposition of greisen molybdenite-chalcopyrite mineralization on parageneses of earlier formed quartz-wolframite veins. Oxidized metal-bearing fluids that formed the Mo mineralization of the Kalguty deposit have high contents of S and are geochemical analogs of magmatic metal-bearing ore-forming fluids of the Central Aldan porphyry Cu-Au-Mo deposits, which are genetically related to alkaline massifs. This suggests the significant influence of the mantle source on the formation of the Kalguty rare-metal ore-magmatic system. The same is evidenced from the sulfur isotope composition of chalcopyrite, molybdenite, and pyrite from ore parageneses, falling in the narrow range of δ34S‰ from -1.2 to +2.9 corresponding to the isotope composition of mantle sulfur.

KW - Fluids inclusions

KW - Metal-bearing ore-forming fluids

KW - Mo-W deposits

KW - Redox potential

UR - http://www.scopus.com/inward/record.url?scp=84963976710&partnerID=8YFLogxK

U2 - 10.1016/j.rgg.2016.04.001

DO - 10.1016/j.rgg.2016.04.001

M3 - Article

AN - SCOPUS:84963976710

VL - 57

SP - 507

EP - 518

JO - Russian Geology and Geophysics

JF - Russian Geology and Geophysics

SN - 1068-7971

IS - 4

ER -