Features of inner structure of placer gold of Anabar region (north-eastern Siberian platform)

In placer regions, where primary sources of gold are not identified, it is necessary to study typomorphic features of placer gold, because it contains important genetic information, necessary for the development of mineralogical criteria of prognosis evaluation of ore gold content. The inner structures of gold from the Anabar placer region are studied, as one of the diagnostic typomorphic criteria as described in prominent method, developed by N.V. Petrovskaya (1973, 1980). Etching of gold was carried out using reagent: HCl + HNO 3 + FeCl 3 + CrO 3 + thioureat + water. The identified inner structures were studied in detail by scanning electron microscope JEOL JSM-6480LV. Two types of gold are identified according to the features of inner structure of placer gold of the Anabar region. The first type is medium-high karat fine well processed gold with significantly changed inner structure. This gold is allochthonous, which was redeposited many times from ancient intermediate reservoirs to younger deposits. The second type is low-medium karat poorly rounded gold with unchanged inner structure. The poor roundness of gold particles and preservation of their primary inner structures indicate close proximity of primary source.