【摘要】 安徽省北部蚌埠隆起区被认为是山东胶东招远金成矿带以西的延伸部分,但蚌埠隆起区内之前一直未发现成规模的金矿床。江山金矿床是最近新发现的中型金矿床,区内成矿作用的时代、赋矿地层的归属仍缺乏系统的年代学证据。文章对蚌埠隆起区内江山金矿床的赋矿地层和相关岩浆岩开展系统的年代学研究,明确了赋矿地层时代归属,并限定了成矿时代的上限和下限。矿床赋矿围岩浅粒岩的结晶年龄为(2496±19)Ma,变质年龄为(2452±47)Ma;斜长角闪岩的变质年龄为(1824±11)Ma,对比区域地层岩性和时代,确定矿床的赋矿围岩为新太古代五河群西堌堆组,而非过去认为的庄子里组。矿床中穿切矿体的脉岩花岗闪长斑岩的结晶年龄为(121.2±1.4)Ma,代表成矿时代的下限;赋矿岩体巨斑花岗斑岩的结晶年龄为(128.3±1.7)Ma,代表了成矿时代的上限。通过与胶东金成矿带的对比,认为蚌埠隆起区与胶东地区的前寒武纪变质基底演化历史相似,江山金矿床的成矿作用类型属于胶东焦家式金矿,在此基础上,推测蚌埠隆起区西芦山岩体和淮光岩体有较大的成矿潜力。更多还原

【Abstract】 It is inferred that the Bengbu uplift area represents the western extension of the Zhaoyuan gold ore deposit,but large deposits have not yet been found in the Bengbu Uplift area. And there is not enough systematic chronological evidence for the metallogenic time and the belongingness of the ore-hosting strata in this area. Jiangshan gold deposit is a medium-sized gold deposit newly discovered in the Bengbu Uplift. Chronology of the deposit was investigated on the ore-hosting strata and the related magmatic rocks, and its ore-hosting strata and ore-forming age were confirmed. The crystallization age of the leptite is(2496±19) Ma and a late metamorphic age is(2452±47) Ma, whereas the metamorphic age of amphibolite is(1824±11) Ma. In contrast to the regional stratigraphic lithology and age, it can be inferred that the host unit is not part of Zhuangzili Formation but probably belongs to the Xigudui Formation of Neoarchean Wuhe Group. The ages of the host rock(gigantic porphyic granite) and the rock stock(granodiorite porphyry), which cut across the orebody, are(128.3±1.7) Ma and(121.2±1.4) Ma. According to the relationship between petrogenesis and mineralization, the age of mineralization of Jiangshan gold deposit is in the range of(128.3 ± 1.7) Ma～(121.2 ± 1.4) Ma. A comparison of the Jiaodong gold belt indicates that the Bengbu lift and Jiaodong region had the similar evolution history of the Precambrian metamorphic basement. The Jiangshan gold deposit belongs to Jiaojia type gold deposit in Jiaodong area. This study suggests that the Xilushan granite and Huaiguang monzogranite can be a preferential area for gold ore exploration.更多还原