FINGERPRINT FEATURES OF PLACER GOLD AND ITS INDICATING SIGNIFICANCE FOR PRIMARY GOLD IN THE NORTHERN TIBET

The fingerprint features (chemical composition) of placer gold has been a important method to seek primary gold. It is shown that the fineness of placer gold in the northern Tibet is obviously uneven and the chemical composition is varied in the east and west parts. Placer gold has inherited from primary gold in the source area, and been clearly remoulded by the later geological events. It is concluded that the primary gold might have multi-source features with short-distance carrying. The features of the native gold microelements indicate that the majority of native gold types are the epithermal ones. Ores are rich in As, Sb, Cu, Pb and Zn, showing being less denuded. It has good prospect to find a large-scale primary gold deposit near the placer gold enriched area.