广东那程银金矿床地质特征

Geological Characteristics of Nacheng Silver-gold Deposit in Guangdong Province

那程银金多金属矿床位于广东省阳春地区。通过采用路线地质调查、构造填图、矿床(点)考察和岩石地球化学等方法,详细总结了矿区地质特征。震旦系云开群和寒武系八村群是区内主要含矿地层,但震旦系Ag元素丰度值明显偏高,因此震旦系形成的矿床规模比寒武系大;矿区整体为一背斜构造,北翼具有低温元素组合特点,南翼具有中温元素组合特点,反映出褶皱的南翼处于抬升,而褶皱的北翼处于下降,因此,北翼矿体的埋藏深度大于南翼;矿区燕山期侵入岩出露处一般都有较好的矿化,加里东期白云母—绢云母不等粒变质砂岩质条带状混合岩出露处矿化较好,而碎裂—糜棱岩化似斑状黑云母钾长石花岗岩出露处矿化一般。

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,deposii investigation and rock geochemistry.The geological characteristics of mineralization are summed up.Firstly,the Sinian Yunkai Group and the Cambrian Baeun Group are the main ore-bearing strata,aml 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.