胶东金矿集区深部找矿重要进展及成矿特征

胶东地区是我国最大的金矿集区，已累计探明金资源储量4 500余吨。通过全面梳理并总结胶东矿集区深部找矿成果，从典型矿床空间分布、控矿要素、矿床类型及规模等方面，系统分析了胶东金矿集中区的主要成矿特征和成矿规律，以期更好地指导该区深部找矿工作。研究表明，三山岛和焦家金矿均已发展成为世界级巨型金矿床，近年来在三山岛北部海域一次性提交金资源量470 t，在焦家成矿带的曲家、东季-南吕、南吕-欣木、朱郭李家、焦家深部和新城深部等矿段提交的金资源量均超过100 t，在纱岭矿段提交金资源量389 t。焦家和三山岛2个巨型金矿床分别沿2条大致平行的焦家和三山岛断裂的对应位置分布，相向而倾，金矿体表现为“阶梯式”分布规律，现已揭露2个成矿台阶，断裂走向的拐弯部位和菱形格状断裂交会部位是成矿的有利部位。在玲珑金矿田，近年来主要沿破头青断裂和九曲断裂探明破碎带蚀变岩型深部金资源储量逾500 t，致使蚀变岩型金矿资源量明显超过了石英脉型金矿，从而改变了该矿田的矿床类型格局，矿化分布总体表现为“上有蚀变岩（主断裂带中）、下有石英脉（主断裂下盘）”的特征。在栖霞金矿田，拓展了沿主要断裂带开展深部找矿的新方向，在台前-陡崖断裂的栖霞笏山村探明了大型蚀变岩型金矿床。在蓬家夼金矿田开展的深部找矿发现了资源量近70 t的牟平辽上深部金矿床，控矿断裂呈铲式阶梯状和舒缓波状展布，矿体产于断裂深部倾角明显变缓处，该矿床的矿石类型与胶东其他金矿床不同，主要为碳酸盐脉型金矿石，被命名为“辽上式”金矿。胶东地区深部找矿成果表明，其深部找矿潜力依然巨大，重点找矿方向有胶西北3条主要成矿带深部、栖霞金矿田和蓬家夼金矿田深部及三山岛北部海域，而在玲珑型花岗岩和郭家岭型花岗岩的深部空间找矿潜力不大。经初步推测，胶东3 000 m深度以浅金资源量不少于6 000 t，5 000 m深度以浅金资源量将会超过10 000 t。

Major Advances on Deep Prospecting in Jiaodong Gold Ore Cluster and Its Metallogenic Characteristics

Jiaodong is the biggest gold ore cluster in China.More than 4 500 t gold resources in total have been proved.By summarizing deep prospecting results，characteritics of typical gold deposits，and ore-controlling factors，this paper analyze the metallogenic characteristics and metallogenic regularity.Research results show that Sanshandao and Jiaojia gold deposit has developed into world-class giant gold deposit.470 t gold resources have been provided by the offshore of northern Sanshandao.In Jiaojia metallogenic belt，more than 100 t of gold resources have been provided by Qujia，Dongji-Nanlv，Nanlv-Xinmu，Zhuguolijia，Jiaojia deep and Xincheng deep ore block etc，respectively.Shaling ore block has provided 389 t of gold resources.Jiaojia and Sanshandao giant gold deposits are distributed correspondingly along Jiaojia fault and Sanshandao fault respectively，and opposite direction dip.In geological section，gold ore bodies occur in the area of flat slope of faults and inflections area where the dip angle of fault changes from steep to gentle，which shows “step-wise” distribution regularities.Now，2 metallogenic steps have be found in both Jiaojia and Sanshandao giant gold deposits.Horizontally，the turning place of fault striking and rhombic style of fault assemblage are ore-forming favored places.In Linglong gold ore field，more than 500 t gold resources of deep fracture zone altered rock type in total have been proved along Potouqing and Jiuqu fault.As a result，gold resource of altered rock type is obviously more than that of quartz vein type.From the tectonic point of view，the relation between different gold deposit type in Linglong gold ore field is the altered rocks above，the quartz veins below.In Qixia gold ore field，a large gold deposit of altered rock type is proved in Hushan village along Taiqian-Douya fault recently.This discovery opens up a new direction of prospecting in the deep of main fault zone.In Pengjiakuang gold ore field，the important achievement of deep prospecting is the discovery of Liaoshang deep gold ore deposit，which nearly 70 t gold resources have been found.The dip angles of ore-controlling fault and mineralized alteration zone in this deposit becomes gentler from shallow to deep，like shovellike，step-wise and slightly wavelike.The ore bodies host in the section of low-angle dip in depth of ore-controlling fault.Ore type of this deposit is carbonate vein type gold ore，which is different from other gold deposits in Jiaodong area.The achievements of deep prospecting in Jiaodong area indicate that deep prospecting in this area still has great potential.The key prospecting directions include：deep parts of three main metallogenic belts in Jiaoxibei area，deep parts of Qixia gold ore field and Pengjiakuang gold ore field，and the offshore of northern Sanshandao.Whereas the potential of prospecting in deep area of Linglong granite suit and Guojialing granite suit is smaller.According to the present condition of deep prospecting，it can be forecasted that there are no less than 6 000 t of gold resource above 3 000 m depth in Jiaodong area，and more than 10 000 t of gold resource above 5 000 m depth.