Single-zircon dating of Precambrian strata in the west sector of the northern Qilian Mountains and its geological significance  

作　　者：Jingwen Mao Zhaochong Zhang Jianmin Yang Biao Song Maobing Wu Guochao Zuo 

机构地区：[1]Chinese Acad Geol Sci, Inst Mineral Deposits, Beijing 100037, Peoples R China [2]Chinese Acad Geol Sci, Inst Geol, Beijing 100037, Peoples R China [3]Gansu Bur Geol & Mineral Resources, Inst Geol Sci, Lanzhou 730000, Peoples R China

出　　处：《Chinese Science Bulletin》1998年第15期1289-1294,共6页

摘　　要：Single_zircon evaporation method was employed in the present study to determine the age of the iron_bearing rock series in Precambrian strata in the western sector of the northern Qilian Mountains. Three zircon ages from the diabase of the Aoyougou ophiolite previously put into Upper Lithologic Formation of the Zhulongguan Group are (1 840±2), (1 783±2) and (1 784±2) Ma respectively, whereas the zircon ages from the welded breccias in the Zhulongguan Group are (733±7), (738±4) and (604±6) Ma respectively. These results show that they should belong to the bottom of the middle Proterozoic and the upper part of upper Proterozoic respectively.Single-zircon evaporation method was employed in the present study to determine the age of the iron-bearing rock series in Precambrian strata in the western sector of the northern Qilian Mountains. Three zircon ages from the diabase of the Aoyougou ophiolite previously put into Upper Lithologic Formation of the Zhulongguan Group are (1 840 ± 2), (1 783 ± 2) and (1 784 ± 2) Ma respectively, whereas the zircon ages from the welded breccias in the Zhulongguan Group are (733 ± 71, (738 ± 4) and (604 ± 6) Ma respectively. These results show that they should belong to the bottom of the middle Proterozoic and the upper part of upper Proterozoic respectively.

关 键 词：single_zircon DATING PROTEROZOIC STRATIGRAPHIC division. 

分 类 号：P534.41[天文地球—古生物学与地层学]