大别造山带核部桃园寨火山岩锆石U-Pb定年及其地质意义  

U-Pb Zircon Dating and Its Geological Significance of the Taoyuanzhai Volcanic Rock, Central Dabie Organic Belt

作　　者：刘敦一[1] 汤加富[2] 周存亭[2] 高天山[2] 沈荷生[2] 杨淳[1] 

机构地区：[1]中国地质科学院地质研究所,北京100037 [2]安徽省区域地质调查所,合肥230011

出　　处：《地质学报》2002年第2期217-221,共5页Acta Geologica Sinica

基　　金：地质行业基金(编号959632);安徽省地质矿产局资助

摘　　要：应用U-Pb和二次离子探针(法国产SIMS 1270)U-Pb法对大别造山带核部桃园寨火山岩中的锆石进行了年龄测定,给出其形成年龄为136～129 Ma。这一研究表明,大别造山带核部存在晚侏罗世—早白垩世火山活动和火山盆地,也说明在这一时期,该区的构造环境与北淮阳地区相似。据现残存的火山地貌和标高,及相邻的北淮阳地区的中生代火山盆地及火山沉积物的厚度,推测其剥蚀深度约 3000 m。Zircons from the Taoyuanzhai volcanic rock, central Dabie orogenic belt, Anhui Province, are dated using conventional and SIMS (1270) U-Pb methods. The eruption age is given at 129-136 Ma, suggesting a Late Jurassic-Cretaceous volcanic event, as well as a volcanic basin in the area. It is also suggested that the tectonic environment was probably similar to that of the North Huaiyang in the north. According to the residual vol-canic topology, the height above sea and comparison to the thickness of volcanic sediments of the adjacent North Huaiyang Mesozoic volcanic basin, the erosion is estimated at about 3000 m in depth.

关 键 词：大别造山带 火山岩 锆石U-PB定年 铀-铅定年 火山活动 构造环境 

分 类 号：P597[天文地球—地球化学]