甘肃洮河裂陷槽金矿成矿地质条件探讨

DISCUSSION ABOUT THE GOLD DEPOSIT CONDITIONS FOR MINERALIZATION OF LOBED SUBSIDENCE FURROW OF TAOHE RIVER IN GANSU

洮河裂陷槽位于西秦岭合作—岷县断裂和腊子口—武都断裂之间的过渡地区,是以三叠系浊流沉积碎屑岩建造为主的重要金矿成矿带,后期构造活动相对较弱。通过对区内地质背景、地球化学特征和典型矿床特征的对比,分析了裂陷槽内金矿床成矿地质条件。认为三叠系碎屑岩地层是金的矿源层,地球化学异常是寻找该类矿床的直接标志,EW向和NW向断裂交汇部位的局部小规模褶皱、断裂和小岩脉的发育程度是矿体富集的决定因素。

The lobed subsidence furrow of Taohe river situated on the transfer area between the Hezuo- Minxian fracture and La Zikou-Wuwei fracture of western QinLing, and it is the important metallogenic zoning of gold deposit in Triassic system, with relatively weak of the deuterogenous structure activation, by contrast with the geological setting, geochemistry characteristic and typical deposit characteristic, discussed gold deposit conditions for mineralization in lobed subsiderce furrow. It＇s believed that the clastic rock bed in Triassic system is the source bed of gold, and geochemistry unconventionalily is the direct sign to search for this deposit, and the develop degree of the fracture, flod of the small scale, with the small veins are the determining factors of enrichement of the orebody.