地质通报Issue(8)：1426-1437,12.
北秦岭柳叶河盆地上三叠统物源区及其与鄂尔多斯盆地的关系--来自碎屑锆石LA-ICP-MS U-Pb年龄的证据
A tentative discussion on the source area of the Late Triassic Liuyehe basin in North Qin-ling Mountains and its relationship with the Ordos basin:Evidence from LA-ICP-MS U-Pb dating of detrital zircons
摘要
Abstract
In this paper, the authors collected quartz sandstone samples from late Triassic Liuyehe basin of North Qinling Mountains in Zhouzhi area, Shaanxi Province, and conducted LA-ICP-MS detrital zircon U-Pb isotope analysis. The results show that the 77 analytical points of the magmatic detrital zircons yielded seven age groups: 256~475Ma, 1500~1680Ma, 1750~2190Ma, 2190~2310Ma, 2400~2650Ma, 2700~2800Ma, and 2850~2960Ma. Among the ages, the youngest age is 256 ± 4Ma, whereas the oldest age is 2954±25Ma;the major Paleoproterozoic age group (1750~2190Ma) accounts for 64%of the total measured points. The zircon age comparison between the Carboniferous Liuyehe basin and the late Triassic Liuyehe basin shows that the Neoproterzoic age is lacking in the Late Triassic Liuyehe basin, which indicates that the uplifting northern part in EW-trending North Qinling Mountains located between Liuyehe basin and Ordos basin during the Carboniferous was removed in Late Triassic and became the secondary prove⁃nance of Liuyehe basin. A comparative study of the age structure of the peripheral terranes shows that the southern part of North Qin⁃ling Mountains, including the Erlangping, Qinling, Danfeng and Liuling groups as well as the magmatic material developed in the Caledonian trench-arc-basin system along the Shangdan suture zone, became the major provenance for the basin. Combined with the paleontologic evidence, the similarity in detrital zircon age distribution pattern between the Triassic Liuyehe basin and the Yan⁃chang formation in southwest Ordos basin strongly suggests that the Liuyehe basin was probably connected with the southern Ordos basin and represented the southern margin of the Ordos basin during the Late Triassic.关键词
柳叶河盆地/晚三叠世/碎屑锆石LA-ICP-MS U-Pb测年/物源区/鄂尔多斯盆地Key words
Liuyehe basin/Late Triassic/detrital zircon LA-ICP-MS U-Pb dating/provenance/Ordos basin分类
天文与地球科学引用本文复制引用
李侃,郭安林,高春云,李兴辉..北秦岭柳叶河盆地上三叠统物源区及其与鄂尔多斯盆地的关系--来自碎屑锆石LA-ICP-MS U-Pb年龄的证据[J].地质通报,2015,(8):1426-1437,12.基金项目
国家基础科学人才培养基金项目（编号XDCX2012-07）、中国地质调查局项目（编号12120113047600）、西北大学大陆动力学国家重点实验室科技部专项 （）
