Polymetallic sulfide minerals

Some of the discharged sulfide particles settle onto the chimney s exterior, where they are buried by the outward growth of anhydrite. Sulfide precipitation within the chimneys, causes copper, zinc, and iron sulfides to deposit and partially replace the anhydrite. Chimneys can build to several meters in height and their orifices range in diameter from 1 to 30 cm. Both the smoke and the chimneys are composed of polymetallic sulfide minerals, chiefly pyrrhotite (FeS), pyrite (FeS2), chalcopyrite (CuFeS2), and sphalerite or wurtzite (ZnS). 

Hirabayashi (1907) defined Kuroko as an ore which is a fine compact mixture of sphalerite, galena, and barite. This definition can be applied to black ore , but not to yellow ore or siliceous ore because these minerals are not abundant in these ores. Kinoshita (1944) defined Kuroko deposit as a deposit genetically related to the Tertiary volcanic rocks, consisting of a combination of Kuroko (black ore), Oko (yellow ore), Keiko (siliceous ore), and/or Sekkoko (gypsum ore) (Matsukuma and Horikoshi, 1970). The deposit is generally defined as a strata-bound polymetallic sulfide-sulfate deposit genetically related to Miocene bimodal (felsic-basaltic) volcanism (T. Sato, 1974). 

In this chapter, we consider the mineral composition of the hydrogenous minerals and how they fitrm. The evaporite minerals have already been covered in Chapter 17. The hydrothermal minerals (polymetallic sulfides) are discussed further in Chapter 19. 

The rest of the chapter is organized as follows. In Section 6.07.2 we discuss the chemical composition of hydrothermal fluids, why they are important, what factors control their compositions, and how these compositions vary, both in space, from one location to another, and in time. Next (Section 6.07.3) we identify that the fluxes established thus far represent gross fluxes into and out of the ocean crust associated with high-temperature venting. We then examine the other source and sink terms associated with hydrothermal circulation, including alteration of the oceanic crust, formation of hydrothermal mineral deposits, interactions/uptake within hydrothermal plumes and settling into deep-sea sediments. Each of these fates for hydrothermal material is then considered in more detail. Section 6.07.4 provides a detailed discussion of near-vent deposits, including the formation of polymetallic sulfides and... 

Fig. 13.1 Distribution of sea-floor hydrothermal vents and related mineral deposits. Numbers refer to high-temperature hydrothermal vents and related polymetallic sulfide deposits (closed circles). Other hydrothermal deposits and low-temperature vent sites, including Fe-Mn crusts and metalliferous sediments, are indicated by open circles (from Hannington et al., 2005). Major spreading ridges and subduction zones are indicated.

Ore deposits associated with volcanic rocks generally exhibit polymetallic (Cu, Pb, Zn, Sn, W, Au, Ag, Mo, Bi, Sb, As and In) mineralization. Sulfur isotopic values of sulfides from these deposits are close to 0%o, suggesting a deep-seated origin of the sulfide sulfur. Clay deposits (pyrophyllite, sericite and kaolinite) are associated with both felsic volcanic rocks and ilmenite-series granitic rocks of late Cretaceous age in the San-yo Belt. 

Fig. 3. Mineralization linked to the ring structures I - Urkuveem (Mo with Ag and Bi, greisen type), II -Keyukveem (polymetallic), III - Kitivelgin (Au, arsenic-antimony association), IV - Belaya Sopka (Sn, cassiterite-sulfide association), V - Shestakovka (Sn with Ag and Bi, cassiterite-silicate association). Total productivities Pj, m %) for more promising catchment areas (outlined) and/or linear and ring structures are numbered.

The aim of this contribution is study the metals distribution, and specifically the indium distribution into the polymetallic mineralization stages from the Pinguino deposit sulfide veins. 

The polymetallic veins are poorly exposed at surface and are characterized by the presence of gossans with remnants of breccias with quartz matrix and oxidized sulfide clasts. Hypogene polymetallic mineralization is characterized by the presence of massive and banded sulfide veins and sulfide breccias up to 13 m thick. This mineralization is developed In... 

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