胶东中生代盆地边缘区金矿成矿特征和找矿方向

Gold Metallogenic Features and Prospecting in the Margin of the Mesozoic Basins, Jiaodong Peninsula

胶东中生代盆地边缘区是近年来金矿勘查取得新突破的地区之一,已陆续探明了牟平金庄、宋家沟、乳山蓬家夼、西涝口、海阳郭城、平度大庄子、栖霞西林、笏山、福山杜家崖等中-大型金矿床。按照其产出特征,可分为蓬家夼式盆缘滑脱拆离带蚀变杂岩型金矿与宋家沟式盆内裂隙密集带蚀变砾岩型金矿二种类型。盆缘区金矿的同位素年龄为128.49~115 Ma,与胶东其它地区金矿年龄一致,成矿物质来源均具有壳、幔混合源特点。通过对该区成矿规律的研究分析,指出了5处重要成矿远景区,预示该区具有巨大的找矿潜力。

Breakthrough in gold exploration is outstanding in the margin areas of the Mesozoic basins in Jiaodong Peninsula where a batch of mid-large gold deposits are successively discovered like Jinzhuang and Songjiagou in Muping, Pengjiakuang and Xilaokou in Rushan, Guocheng in Haiyang, Dazhuangzi in Pingdu, Xilin and Hushan in Qixia, and Dujiaai in Fushan. Judging from the occurrence features, this area possesses two gold metallogenic types, namely the Pengjiakuang type-（the alteration complex gold deposits in the slip-detachment belts along the basin margins） and the Songjiagou type-（the alteration conglomerate gold deposits in the fissure- abundant belts inside the basins）. In accord with other areas＇ metallogenic age in Jiaodong, the isotopic age of the gold deposits in the basin margins drops into 128.49-115 Ma, and the metallogenic material is characterized by the mixture of crust and mantle derived substances. From the study and analysis of local metallogenic regularities, this article defines five significant metallogenic areas with tremendous prospecting potential.