Iron meteorite Big Dolguchan: results of mineralogical-geochemical researches

The results of mineralogical and geochemical studies of iron meteorite Big Dolguchan are discussed. The meteorite is characterized by taxitic structure, 85-90 % nickel-iron composition contains more than 50 microelements, abnormally enriched Pt, Rh, Ru, Ir, Tl, W, Pb, Mo, B, Re. Also the admixture of free isotopically light carbon is revealed. The mineral composition is determined by the iron-nickel intermetallic compounds and alloys, troilite unprecedented chemical and nominal composition of chromespinelides. For the first time in meteorites we discovered a silicon phase, which is probably composed of silicon hydrides or (and) lithium silicide. From the combination of microstructural and mineralogical and geochemical properties of the Big Dolguchan is to be attributed to a group of single Anomalies UNGR.