EH4方法在隐爆角砾岩型盲矿预测中的应用——以河南嵩县下蒿坪金矿为例

河南嵩县下蒿坪金矿位于华北地台南缘、马超营深大断裂中段外方山多金属成矿带上。出露地层以熊耳群鸡蛋坪组安山岩为主。区内断裂构造发育,岩浆活动强烈,成矿条件好。电性参数测量表明,隐爆角砾岩与矿石的电阻率差异显著,具备找矿勘查的地球物理前提。在EH4连续电导率测深剖面上,清晰显示隐爆角砾岩体呈椭圆形,在其边部存在明显的低阻异常区,对比已有地质资料,推断这些低阻异常是由矿化的隐爆角砾岩引起的,是成矿有利地段或矿化体的电性反映。坑道内揭露的爆发角砾岩矿体表明,EH4方法在该区判别爆发角砾岩体与矿化角砾岩体(赋矿部位)是有效的。

The application of EH4 sounding to forecast of the blind-ore related to cryptoexplosive breccia —Xiahaoping Gold Deposit in Songxian,Henan Province for Example

Xiahaoping gold deposit is located in the southern margin of the north China platform and in the Waifangshan polymetallic ore belt of the middle Machaoying fracture.Andesite of Jidanping Formation of Xionger Group is the main stratum exposed in the ore deposit area which is characterized by development of faults and magmatism and good metallogenic conditions.Electric parameters measurement shows that the resistivity of cryptoexplosive breccia body and ore is sharply different,thus here is of the premise of geophysical exploration of explosive breccia type gold deposit.The EH4continuous conductivity sounding profiles clearly shows a oval cryptoexplosive breccia body and a obvious low resistivity anomaly area at its edge.Based on geological data available it is inferred that the abnormality of low resistivity zone is caused by mineralizer cementing of cryptoexplosive breccia thus the electric reflection of mineralized body.The breccia ore body revealed by aditing shows that EH4is effective for distinguishing general explosion breccia body and mineralized breccia body.