METALLOGENIC LAW OF PLACER GOLD DEPOSITS IN NORTH HUNLUNBEIR LEAGUE

Neotectonic movement exposed gold bearing geological bodies in North Hulunbeir League to weathering and degradation, and resulted in gold activation. Rivers and the tributaries developed with wide drainage and sufficient flow providing favorable conditions for gold migration and enrichment. Modern low mountain and mound and wide valleys are favorable for placer gold preservation. Several tens of placer gold deposits have been found in this area and most are of river valley type. Gold occurs mainly in clay sandy gravel of sandy gravel layers. Gold enrichment is closely related with geomorphy of valley. Convex bank and variation parts of river bed, door close mouth, door facing hill are favorable places for placer gold deposition. Gold source is from Caledonian and Hercynian granite. At last, exploring guides for placer gold deposit are pointed out on the base of study of gold source, placer gold distributive features and enrichment law.