作　　者： ; ; ; ; ; ; ; ;

机构地区： 西北大学地质学系大陆动力学国家重点实验室

出　　处： 《兰州大学学报（自然科学版）》 2013年第3期313-319,共7页

摘　　要： 对准噶尔盆地东北部Db1井中生界晚三叠世-中晚侏罗世三组砂岩样品,共计199颗锆石进行了显微结构和LA-ICP-MSU-Pb定年分析.根据锆石矿物特征,阴极发光图像和年龄分布特征,结合区域沉积古流体系的地质约束,对研究区晚三叠世-中晚侏罗世的沉积物源环境及其地质构造意义进行了讨论.结果表明:碎屑锆石主要物源可能包括准噶尔盆地内部、准北周缘造山带,碎屑锆石U-Pb年龄以较宽的时域分布在150～1 224 Ma,并在统计分布上存在4个主要的538～360 Ma,354～271 Ma,267～208 Ma,185～150 Ma年龄区间及对应的510,490,410,330,290,250,162 Ma7个峰值年龄.碎屑锆石出现162 Ma的峰值年龄,反映了燕山运动对准噶尔地区的影响. Three groups of sandstone samples in ages ranging from the Late Triassic to Mid-Late Jurassic were collected from the Dbl well in the northern Jungger Basin.The U-Pb ages of 237 single zircon grains contained in the sandstone samples were anslyzed by the LA-ICP-MS method.According to the mineralogical characteristics,zircon cathodoluminescence image and the age distribution characteristics,combined with the constraints of palaeocurrent,the sediment sources and geological significance were discussed.It is shown that the main source for detrital zircon in Junggar Basin might include an internal and quasi north peripheral orogenic belt.Detrital zircon U-Pb ages were in a wild range of 150～1 224 Ma,and four major age groups,i.e. 538～360 Ma,354～271 Ma,267～208 Ma,185～150 Ma had existed,corresponding to seven major peak age at 510,490,410,330,290,250,162 Ma.Detrital zircons had a peak age 162 Ma,implying that the Yanshanian movement had affected the tectonic evolution in the northern Jungger Basin.

关 键 词： 碎屑锆石 激光剥蚀等离子体质谱 定年 物源分析 准噶尔盆地

领　　域： [天文地球] [天文地球]