| Реферат: | eng: Economic Ag-Sb deposits are located within four large ore districts of Central Asia: SE Altai-NW Mongolia, SE Pamir (Tajikistan), Talas (Kyrgyzstan) and Verkhoyansk province (Yakutia), where Ag-Sb ores are spatially associated with tin mineralization. The geology, mineral composition and geochemistry of the Ag-Sb deposits, age of mineralization, distribution and genesis are presented in this paper. Results of new studies show that Ag-Sb ores commonly occur within Sn ore provinces and can be divided into three groups according to their relationships with tin mineralization. Ag-Sb deposits of the first group are spatially isolated from Sn-W ore fields and from metamorphic haloes of Sn-bearing granitoids (pre-granitic deposits of the Mangazeisky ore cluster in Yakutia and deposits of the Asgat-Ozernoe ore zone in the SE Altai-NW Mongolia). A 240 ± 3.5 Ma 39Ar/40Ar age of Ag-Sb mineralization was determined for the Asgat deposit (SE Altai-NW Mongolia), which correlates well with the 243 ± 3.7 Ma 39Ar/40Ar age of alkaline mafic intrusions (lamprophyre dike). The Ag-Sb ore appears to be younger than Sn-W mineralization (352 ± 6.0 Ma) related with granite of the Yustid complex (355.7 ± 8.6 Ma). The second group comprises granite-hosted Ag-Sb deposits of the Bazardara ore cluster (SE Pamir) of Paleogene age (44 ± 1.5 Ma) located within a tin ore cluster, but separated in time from the Cretaceous Sn mineralization (98.5 ± 1 Ma, Ar-Ar). Ag-Sb ore veins of the third group are located within tin ore clusters and are nearly coeval with tin mineralization (post-granitic Ag rich ore of the Mangazeiskoe, Prognoz and Menkechenskoe deposits, Verkhoyansk province). A close spatial and temporal relationship of Ag-Sb deposits with Sb-Hg mineralization and alkaline mafic magmatism is observed. Helium isotope systematics from the ore-forming fluids of Ag-Sb Akjilga deposit (Pamir) confirm the role of mantle helium in the ore-forming process. Another important indicator of a mantle source in these Ag-Sb deposits is the Hg content in the ores; Hg being a typical element of mantle origin. Isotopic (3He/4He, 87Sr/86Sr, Pb, S) and geochronological data demonstrate that Ag-Sb deposits are polygenetic in sources of ore matter and relate to the mantle-crustal ore-magmatic systems. © 2008 Elsevier B.V. All rights reserved.
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