Tourmaline from Late Quartz Veins of the Murtykty Gold Deposit, Republic of Bashkortostan

Abstract

Tourmaline, an intermediate member of the oxyschorl–oxydravite–oxymagnesio-foitite-bosiite series with a predominance of the oxy-dravite-bosiite end-member, was studied from late calcite-quartz veins in the eastern zone of the Murtykty gold deposit (Republic of Bashkortostan). Sulfide mineralization in veins includes rare chalcopyrite, pyrite, sphalerite and galena. Accessory minerals are xenotime-(Y), vanadium-containing rutile and fine high-fineness gold. Supergene mineralization resulted from decomposition of carbonates, sulfides and rock-forming silicates includes kaolinite, hydroxides of Mn (chalcophanite, psilomelane) and Fe (goethite and limonite ochers), mainly developed in vein cavities ; chalcopyrite is replaced by cuprite and malachite. The composition of tourmaline is close to metamorphic dravite of orogenic gold deposits and tourmaline of gold-porphyry deposits, transitioning from porphyry to epithermal. Two possible B sources for the formation of tourmaline are considered: sedimentary rocks of the paleoisland-arc complex and granodiorites of the Mansurovo pluton. Figures 9. Table 1. References 36. Key words: tourmaline, boron, gold, xenotime-(Y), Murtykty deposit, Republic of Bashkortostan.

Geology and gold content of carbonaceous shale in Baikal mineralization site, Southern Ural

“…5j). This tourmaline is high-magnesia, free from impurities of metals, Mn, F and As typical of tourmaline from porphyrite and granite deposits [16][17][18], and is similar to metamorphogene dravite from orogenic gold and gold-sulfide deposits as well as to tourmaline from gold-porphyritic bodies [18][19][20][21][22].…”