Geological structure and prospects of noble metal ore mineralization of the Khayrkhan gabbroid massif (Western Mongolia)

An analysis of the distribution of noble metals in zones of sulfide mineralization makes it possible to justify the isolation of four ore-bearing horizons with a specific geochemical zonation. A rise in the gold content relative to palladium and platinum is observed from the bottom upwards along the section of the stratified series of gabbroids. The study of the mineral phases of sulphides and the noble minerals itself indicates the evolution of hydrothermal solutions, which determines the different activity and mobility of the fluid (mercury, tellurium, sulfur) and ore (copper, nickel, iron, platinum, gold and silver) components

The Khairkhan dunite-troctolite-gabbro massif (Lake Zone of the Western Mongolia) - example of syncollision Middle Cambrian mafic intrusion

Geological, mineralogical, petrochemical and geochronological data are considered for the Khairkhan dunite-troctolite-gabbro massif in the Lake zone of Western Mongolia. The massif intrude the Lower Cambrian molasse stratum and intruded by the Middle Cambrian diorite-plagiogranite bodies (507 Ma). Mineralogical, petrographic and geochemical data show typical suprasubduction characteristics: high An component of plagioclases with increased iron content of olivines, high whole-rock alumina content, low contents of titanium and alkalis, Ta, Nb, Zr and Hf minima. The layered series is characterized by a layers of orbicular gabbros, which can be considered as gabbro-gabbro mingling. At the same time, high-temperature viscous-plastic deformations are characteristic of the layered series, which cover the entire volume of the intrusion. These observations, together with geological and geochronological data related to the melting of the suprasubduction mantle in the Cambrian-Ordovician time, allow treating the Khairkhan massif as an example of syncollisional stratified gabbroids