Fluidolites as a Source of Primary Gold–Platinum Mineralization in the Poperechnoe Deposit (Malyi Khingan Range,Russia)

A genetic relationship is shown for the noble-metal mineralization (up to 11.3 g/t of Pt and platinoids and 2.58 g/t of Au) discovered in the Poperechnoe Fe–Mn deposit and the fluid–explosive breccias. The composition of platinoid minerals is in agreement with the characteristics of ore and placer formations of the Ural–Alaskan type and corresponds to the isoferroplatinum–osmium igneous paragenesis. The noble metals were crystallized at the conditions that should take place at the crust–mantle boundary under partial melting of the slab rocks. The near-surface occurrence of these metals is caused by the rising of high-mobile fluid flows. The data obtained testify to the expedience of searches for noble metals associated with occurrences of fluidolites.     

Igneous Rocks,Fluidolites, and Rodingites of Paleocene Explosive Structures of the Taukha Terrane (Sikhote-Alin)

Geology of Ore Deposits - The Taukha terrane of the Sikhote-Alin hosts outcrops of rocks with unusual structural and textural features, the compositions of which vary from ultrabasic to...     

The role of ophiolite in metallogeny of the Sikhote-Alin region

Metalliferous sediments of the Triassic siliceous formation of the Sikhote-Alin (manganese-silicate rocks and cherts with dispersed rhodochrosite, silicate-magnetite ores, and jasper) and skarns of the Dalnegorsk and Olginsk ore districts were initially the wash away products (Late Anisian-end of the Triassic) of the lateritic weathering crust on ophiolite in the islands. Manganese, iron, and other metals were deposited in the sediments of both lagoons (present-day, skarns) and island water areas (manganese-silicate and siliceousrhodochrosite rocks, silicate-magnetite ores, and jasper). Skarns contain boric and polymetallic ores thus indicating the occurrence of both shallow (periodically drying up) and quite deep (with hydrogen sulfide contamination zones) lagoons. Lead was deposited in protoliths of the skarn deposits in lagoons from the beginning of the Carboniferous to the beginning of the Late Anisian (initial island submergence). Tin, tin-leadzinc (with Ag), and silver-lead-zinc (with Sn and Au) vein deposits (Late Cretaceous-Paleogene) of the Taukha and Zhuravlevka Terrains contain lead deposited in the sediments flanking the islands of water areas with the hydrogen sulfide contamination zones, in the Carboniferous-Permian and Triassic metalliferous sediments.     

Phlogopite-olivine rocks of the Taukha terrane in southeastern Sikhote Alin

The Paleocene ultraferrous Mn-rich phlogopite-olivine rocks of the Taukha terrane belong to the alkaline ultrabasic rocks of the potassic series. The olivine is represented by hortonolite, while the phlogopite is enriched in Cl. Other minerals are represented by Ti-magnetite, Mn-rich ilmenite, Zn-rich pleonaste, apatite, and zircon. There are also epigenetic serpentine, talc, carbonates, magnetite, breithauptite, nickeline, hedleyite, cobaltite, tsumoite, auricupride, cuproauride, and other minerals. The phlogopite-olivine rocks possibly represent a part of a magmatic complex previously unknown in Sikhote Alin, the rocks of which are associated with fluidolites of a large diatreme. There are grounds to suggest that they were formed by the injection of fluid-rich (mainly, H₂O, Cl, F, and S) deep magmas into the upper lithosphere. Based on these specific features, as well as the sharp K predominance over Na and the enrichment in some incompatible elements (Sn, Ta, Nb, and Zr), the phlogopite-olivine rocks are the most close to lamproites but differ in the high contents of Fe, Mn, Au, Pt, and Pd and in the olivine’s composition. The manifestation of such magmatism in the Taukha terrane records the transition from subduction to transform continental margin settings.     

Mineralogy and genesis of the Belogorsk skarn-magnetite deposit,primorye

The particularity of the formation of the skarn lodes of the Cretaceous-Paleogene Belogorsk deposit is the intense replacement of the early mineral assemblages (the decomposition of garnet, pyroxene, and pyroxenoids) with decreasing temperature, the increase in the amount of magnetite at the expense of Fe released from the decomposed minerals, and the formation of quartz and volatile-rich compounds (calcite, fluorite, amphibole, and sulfides). The geochemical and mineralogical similarity suggests a genetic relation between the manganese skarn lodes of the Belogorsk deposit (the Ol’ginsk ore district) and the stratabound bodies of the manganese silicate rocks (the Triassic contact metamorphosed metalliferous sediments) of the adjacent Shirokaya Pad area (as a source of matter).     

Biological activity and physicochemical properties of thermally activated water types: Mollusk-based bioassay

Physicochemical and bioassay methods are used to carry out a comprehensive study of the properties of two types of activated waters: “thermally activated,” i.e., thermal water, referred to as “white spring” or “cold boiling water” in folk medicine, and “melt” water after quick freeze. The test object for bioassay were apple shell mollusks Pomacea canaliculata from a laboratory culture used to carry out patented and widely tested methods of freshwater quality bioassay. Oxygen and hydrogen peroxide concentrations and pH were determined in water. The integral biological activity of water was evaluated by a method based on the use of absorption spectra to evaluate the rate of redox transformation in the quinone-hydroquinol system. Similar studies were carried out with three types of reference samples: settled original tap water, the same water cooled to the freezing point, and water artificially enriched with hydrogen peroxide. The water activated by thermal impact has been found to have higher biological activity than the original tap water.     

Geochemistry and genesis of metamorphosed volcanic rocks in the Kholodnikan greenstone belt,southern Aldan Shield

The Kholodnikan Complex consists of two units: lower volcanic and upper volcanic-sedimentary. The distributions of major and trace elements suggest that the protoliths of the lower unit were volcanics of the komatiite-tholeiite series (komatiite-basalt association) and those of the upper unit were volcanics of the calc-alkaline series (andesite-dacite-rhyolite association). The model assumed for the genesis of these associations involves two stages: (1) decompression-induced partial melting of the material of an ascending mantle plume with the derivation of melts of the komatiite-basalt association and (2) derivation of volcanic rocks of the andesite-dacite-rhyolite association via the partial melting of various rocks in the basement of the Aldan Shield under the effect of the heat of the ascending mantle plume. The magmatic protoliths of the Kholodnikan Complex were formed in the Paleoproterozoic at 2.41 Ga.