西北地质2017，Vol.50Issue(3)：92-104,13.
西秦岭伯阳镇中泥盆统碎屑岩的岩石学、碎屑锆石U-Pb年龄及其地质意义
Geological Significance of Detrital Zircon U-Pb Age of Middle Devonian Proximal Sedimentary Rocks in Boyang Town, Western Qinling Orogenic Belt
摘要
Abstract
The petrological study of Middle Devonian sandstones and conglomerates in Boyang area,Western Qinlingorogenic belt indicates that their composition maturity and structure maturity are very low,with the characteristics of the proximal deposit.In addition,the conglomerate has a few of the mylonitic gravels.The clastic zircons of sandstone interbeds from the Middle Devonian conglomerate in Boyang area are characterized by magmatic zircons.By clastic zircon LA-ICP-MS U-Pb dating of the sandstone interbeds,the age spectra of clastic zircon can be divided into 4 groups:①440～480 Ma,accounting for about 3％;②540～600 Ma,accounting for about 40％;③880～1 020 Ma,accounting for about 79％;④1 040～1 080 Ma,accounting for about 13％.The age of 880～1 020 Ma shows the strongest peak,which is in accordance with the age of the Jinning period of Neo-proterozoicmagmatism in the Western Qinlingorogenic belt,and also is in accordance with age of the Rodinia supercontinent aggregation event.Integrating with the regional geological material,it is proposed that a significant tectonic uplift-erosion existed in the studied area during Middle Devonian.The clastic sediments of Middle Devonian strata mainly came from both of the Western Qinling and the Northern Qilian orogenic belt,so it is deduced that no longer exists deposition barrier zone in the area between the studied area and the Western Qinlingorogenic belt during Middle Devonian,and both of the Qinling and Qilian orogenic belts were possibly really amalgamated.关键词
西秦岭-祁连结合区/中泥盆统/碎屑锆石/LA-ICP-MS年代学Key words
conjunction area of Western Qinling and Qilian/Middle Devonian/detrital zircon/LA -ICP-MS dating分类
天文与地球科学引用本文复制引用
李亦飞,杨传茂,樊靖,赵明..西秦岭伯阳镇中泥盆统碎屑岩的岩石学、碎屑锆石U-Pb年龄及其地质意义[J].西北地质,2017,50(3):92-104,13.基金项目
长江学者和创新团队发展计划项目“西秦岭伯阳地区上泥盆统砾岩的构造意义”(IRT1281) （IRT1281）
