Geological Characteristics of Nacheng Silver-gold Deposit in Guangdong Province

Nacheng silver-gold polymetallic deposit is discovered in Yangchun area,Guangdong Province.The prospecting works of the deposit were strengthened by using the method of route geological investigation,structure mapping,deposit investigation and rock geochemistry.The geological characteristics of mineralization are summed up.Firstly,the Sinian Yunkai Group and the Cambrian Bacun Group are the main ore-bearing strata,and the formation of the deposit in Sinian is bigger than in Cambrian,as the Ag in Sinian is higher.Secondly,the tectonic is relatively complex,and is an anticline in the whole mining area,whose north wing with low temperature element assemblage characteristics and south wing with middle temperature element combination characteristics,which reflect that the fold is uplift in the south wing and fallen in the north wing.Therefore,the buried depth in the north wing is greater than in the south wing.Thirdly,in the outcrop place of the Mesozoic intrusive rocks and the Caledonian banded migmatite which is the Muscovite-sericite unequigranular metasandstone,the mineralization can be better.However,the mineralization is generally not good enough in the outcrop place of the biotite K-feldspar granite which is fragmentation-mylonitized and renders porphyraceous.