Native Gold of Pseudo-Ore Habit in the Cretaceous Conglomerates (Aldan–Stanovoi Shield, Southeastern Siberian Platform)

For the first time, poorly-rounded gold of ore habit is found in an intergrowth with quartz, feldspar, ilmenite, zircon, and other minerals, along with well-rounded placer gold, during the study of the mineralogical and geochemical features of native gold from the Cretaceous conglomerates of the central part of the Aldan–Stanovoi shield. However, the detailed analysis has established that gold of ore habit belongs to gold of pseudo-ore habit. This gold is characterized by a pitted-tubercular surface, “intergrowths” of gold with minerals of the host sediments, and through holes. The discovery of gold of pseudo-ore habit in the Cretaceous conglomerates indicates the transformation of placer gold as a result of diagenesis processes rather than superimposed later ore mineralization. We previously discovered gold of pseudo-ore habit in the Devonian conglomerates of the Timan Ridge, as well as in the Jurassic and Permian conglomerates in the eastern part of the Siberian Platform. The presence of such gold was the reason for searching for ore sources in the studied territories, which did not lead to positive results. In general, identification of gold of pseudo-ore habit in conglomerates of various ages from the Archean to the Cenozoic makes it possible to predict more correctly the formation of gold deposits and to select search methods.