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 lat eritic 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 con tamination zones) lagoons. Lead was deposited in protoliths of the skarn deposits in lagoons from the begin ning of the Carboniferous to the beginning of the Late Anisian (initial island submergence). Tin, tin lead zinc (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.
GEOLOGYThe Triassic Sikhote Alin siliceous formation of the Sikhote Alin (Taukha and Samarka Terrains) con tain the Au , Pt , and Pd rich contact metamor phosed sediments such as manganese-silicate rocks and cherts with dispersed rhodochrosite, silicatemagnetite ores, and jasper [1]. In the Dalnegorsk and Olginsk ore districts (Taukha Terrain), there are Mn rich Late Cretaceous-Paleogene skarn deposits with polymetallic, iron, and boric ores. They are confined to the fragments of the Carboniferous-Permian and Triassic reefs formed, as is suggested [2], on the mafic guyots. Formation of the mentioned deposits was sup posed to be related to the magmatic source of the ore substance. However, in recent years the scientists have obtained the data indicating the genetic relation between the skarn deposits and the Triassic metallifer ous sediments (as a possible source of metals) [1]. As a result, the comparative studies were carried out to establish the real role of magmatic and sedimentary processes in the development of the skarn deposits.According to the data acquired, the metalliferous sediments and skarns initially were the wash away products of lateritic weathering crust on ophiolite in the islands. Manganese, iron, and other metals were deposited in both lagoons and island water areas. Skarns contain boric and polymetallic ores, thus indi cating the occurrence of both shallow and quite deep (with the hydrogen sulfide contamination zones) lagoons. The geochemical specific features of the par ent igneous rocks were revealed in the lagoon facies (present day, skarns) and water area facies (metamor phosed metalliferous sediments) in spite of significant differentiation of the substance in the sedimentary process. According to the results of comparis...
