赣南牛形坝银金多金属矿区隐爆角砾岩分带性及深部形态特征

Zonation and Deep Morphology of Crypto-Explosive Breccias in the Ninxingba Ag-Au Polymetallic Deposit,Southern Jiangxi Province

牛形坝银金多金属矿区位于赣南于山成矿带中段,主要矿床类型为破碎带蚀变岩型,与燕山期次火山岩热液活动有关。本文对矿区内部的隐爆角砾岩进行了详细的地质和地球物理调查研究,根据角砾的特征可将其分为四个相带:爆破角砾岩带、震碎角砾岩带、震裂裂隙带和板理带,其中震碎角砾岩带含矿性最好,爆破角砾岩带次之;依据可控源音频大地电磁测深结果,显示在隐爆角砾岩区域存在明显的低阻异常现象,揭示角砾岩可能呈筒状向深部延伸,并具有良好的找矿潜力。

The Niuxingba Ag-Au polymetallic deposit is located in the middle section of the Yushan metallogenic belt,southern Jiangxi Province.h is of the facture zone-alteration type,associated with the hydrothermal activities of subvolcanic rocks in the Yanshanian period.Detailed geological and geo- physical survey of crypto-explosive breccia has been conducted in this area.The breccias can be divided into four facies zones： explosive facies,shattering facies,cracking facies and foliation facies,among which the shattering facies has the largest potential to contain ores,followed by the explosive facies. Re- sults of CSAMT surveys indicate that there exist low-resistivity anomalies near the crypto-explosive breccia,implying that this rock body may extend down- ward to the deep subsurface like a cylinder,and showing a great potential of mineralization there.