对华南小岩体找大矿问题的探讨

国内外一些规模很大的金属矿床常常出现在一些规模不大的小岩体附近或者小岩体本身就含矿,由此出现了"小岩体成矿"甚至成大矿的现象,如江西德兴铜矿田、湖南骑田岭钨多金属矿集区、广西大厂锡多金属矿集区、广东贵东铀矿田等都存在这种现象。通过对华南扬子成矿省和华南成矿省小岩体成矿多种现象的分析,认为小岩体成矿对于成矿时代、矿床类型、矿种及成因等并无特定的选择,但可能更多地反映了矿床的保存条件,而其深部往往有大岩基。大岩基周围的小岩体尤其值得重视,而孤立的小岩体可能成矿不好,大岩基内部的小岩体以往被忽视了,斜向侵位的小岩体对于结晶分异和多矿种组合具有特别重要的意义。华南地区目前对于小岩体成矿的问题,探讨更多的实际上是小岩体的找矿问题,而对于小岩体成矿机制的研究程度还比较低,需要加强。

Discussion on the Issues of Exploration Large Deposits Around Small Intrusions in South China

It is a common phenomenon that large-scale mineral deposits occur around small intrusions or host within small intrusive bodies domestic and oversea.Such phenomena can be called as “mineralization with small intrusion”.The phenomena occur in Dexing copper ore field in Jiangxi,Qitianling tungsten-polymetal ore concentration area in Hunan,Dachang tin-polymetal ore concentration area in Guangxi and Guidong uranium ore field in Guangdong,etc.Based on the variety phenomena of mineralization with small intrusion in South China metallogenic province and Yangtze metallogenic province,there is no choice for specific metallogenic epoch,deposit types,minerals assemblage or genesis, etc.Such phenomenon may reflect the preservation conditions of deposits more than ore genesis,and there is often a large batholith below the small intrusions with ore deposit.It is especially noteworthy for small intrusions around a large batholith,while isolated small intrusions may be poorly mineralized.As to the small intrusions intruded within large batholith,which has been ignored in the past,those small intrusions obliquely emplaced into host rocks might be important for mineralization.More attention has been paid on exploration large-scale deposits around small intrusions than the research on the mechanism of mineralization by small intrusion in South China,so that the study extent of＆amp;nbsp;mineralization mechanism,which is still relatively low,needs to be strengthened.