铜陵地区晚古生代岩浆活动的发现:来自凤凰山岩体ZK66钻孔岩心辉绿岩锆石U–Pb定年的证据  

The discovery of late Paleozoic magmatism in Tongling area:Evidence from zircon U-Pb dating of diabse in Fenghuangshan ZK 66 drilling core

作　　者：吴才来[1] 董树文[2] 王次松[3] 高前明 闫永涛[3] 李翔[3] 郜源红[1] 雷敏[1] 秦海鹏[1] 李名则[1] 刘春花[1] 

机构地区：[1]中国地质科学院地质研究所,北京100037 [2]中国地质科学院,北京100037 [3]安徽省地质矿产局321地质队,安徽铜陵244033

出　　处：《中国地质》2013年第3期715-729,共15页Geology in China

基　　金：国家专项(SinoProbe-05-05);自然科学基金项目(40921001;49772106;40472034和40672049);中国地质调查局地调项目(1212011120160;1212010918007;1212010818090;1212010611803和1212010711816)共同资助

摘　　要：凤凰山花岗闪长岩是铜陵地区出露面积最大的岩体,约10 km2,属高钾钙碱性系列。位于该岩体西北角的朱家山附近ZK66钻孔揭示,岩体超覆于三叠纪碳酸盐岩地层之上。除在浅部见到花岗闪长岩之外,深部主要见到晚泥盆世—二叠纪地层。特别是在石炭纪大理岩中见到辉绿岩和花岗斑岩,其锆石LA-ICP-MS U-Pb年龄分别为304 Ma和132 Ma,证明本区存在晚古生代岩浆活动,而中生代花岗质岩浆活动可能持续到132 Ma。晚石炭世辉绿岩的发现,说明该时期海底是一种拉张环境,海底喷流作用可能与岩浆活动有密切的成因关系,为该时期形成大型矿床奠定了基础。Abstract：Fenghuangshan granodiorite with an outcropped area of approximately 10 km2 is the largest pluton in Tongling area, belonging to high-K calc-alkaline series. ZK 66 drill hole at Zhujiashan located in the northwest comer of the Fenghuangshan pluton revealed that the pluton overlaps on the top of Triassic carbonate strata. Besides the granodiorite seen in the shallow part of the ZK 66 dril/hole, the Late Devonian-Permian strata can also be found in the depth of the drill hole. Especially, the diabase with an age of 304 Ma and the granite porphyry with an age of 132 Ma were found in the Carboniferous marble, indicating the existence of late Paleozoic magmatism and probably the Mesozoic granite magmatism which lasted until 132Ma. The discovery of the late Carboniferous diabase reveals a sea-floor spreading environment and also indicates the close genetic relationship between the marine exhalation and the magmatism, which laid a solid foundation for the formation of a large ore deposit in that period.

关 键 词：锆石U–Pb定年 辉绿岩 花岗斑岩 钻孔ZK66 铜陵朱家山 

分 类 号：P588.124[天文地球—岩石学] P597[天文地球—地质学]