地质论评Issue(1)：172-182,11.
鄂尔多斯盆地西南缘上奥陶统平凉组碎屑岩锆石U-Pb年龄及物源分析
U-Pb Dating of Detrital Zircon from Upper Ordovician Pingliang Formation in Southwest Margin of the Ordos Basin and Provenance Analysis
摘要
Abstract
The U-Pb ages of single zircon grains contained in the sandstone samples were analyzed by the LA-ICP-MS method,the sediment provenances and geological significance were discussed.The results show that:①The detrital zircon age of the tuffaceous sandstone from the Upper Ordovician Pingliang Formation can be obviously divided into three groups,the first group is Early Paleozoic which ranges from 407 ~477Ma,the peak value is 454Ma,accounting for about 72.5% of the total dates.The second group is Meso—Neoproterozoic which ranges from 588~1548Ma,the peak value is 962Ma,accounting for about 22.5% of the total dates.The last group is Paleoproterozoic which ranges from 1612 ~2496Ma,accounting for about 5% of the total dates.② The group of 407~477 Ma indicates that its material provenances may mainly come from the North Qinling—Qilian island-arc complex belt in adjacent regions.The group between 588~1548Ma and 1612~2496Ma indicates that its material provenances were mainly from the North Qinling orogenic belt and the Qilian orogenic belt,with the little of material from the basement of North China block.③A comprehensive analysis shows that the material provenances of Pingliang Formation were much more complicated and characterized by obvious diversity and complexity.The indication is that sedimentary environment is the limits of residual marginal sea basin between North Qinling—Qilian island-arc complex belt and the southwest of Ordos block in the Pingliang age Ordovician.关键词
上奥陶统平凉组/锆石LA-ICP-MS U-Pb定年/物源分析/鄂尔多斯盆地Key words
Upper Ordovician Pingliang Formation/zircon LA-ICP-MS U-Pb dating/provenance analysis/Ordos Basin引用本文复制引用
杨甫,陈刚,陈强,丁超,高磊,雷盼盼,张文龙,师晓林,童明军..鄂尔多斯盆地西南缘上奥陶统平凉组碎屑岩锆石U-Pb年龄及物源分析[J].地质论评,2015,(1):172-182,11.基金项目
文为西北大学大陆动力学国家重点实验室科技部专项经费（编号BJ14252）、国家自然科学基金（编号41172101）、中国地质调查局油气资源项目（编号1212011220761）和国家基础科学人才培养基金（编号XDCX2014-18）资助的成果。 （）
