Geological features and prospecting direction of the Fengjiachang gold deposit, Gansu

The Fengjiachang gold deposit is located in the adjoining part of Qilian to North Qinling orogenic belt. The gold mineralization is controlled by the nearly EW striking fault in Liziyuan Group Muqitan Formation of Sinian to Ordovician system and andesite branch of Xiaoshanpo strictly. It has been found there were 4 gold ore-forming belts that spread in parallel and equal distance. The major gold mineralization types are the quartz-vein types, others are the tectonic alternation rock types. The gold minerals are dominated by the electrum, and others are the gold-silver mineral. Gold occurs mainly in shape of interparticle gold, fissure gold or inclusion gold are taken the second place. The largest gold grain size is 0.58 mm×0.96 mm×0.22 mm, gold grade are 8×10~(-6)～10×10~(-6).The mineralization stages include: quartz, pyrite-quartz, pyrite veinlet, multi-metal sulfide and calcite-quartz. The multi-metal sulfide stage is the main mineralization stage among them. The founded gold mineralization fault and the internal or external contact zone of rock bodies provide the direction of gold prospecting in this area.