摘要
根据柯坪(KP)大湾沟剖面及塔北地区TP3,TP7和KQ1等井下志留统柯坪塔格组砂岩样品岩石薄片、重矿物、锆石SHRIMP U—Pb测年分析结果,应用Dickinson三角图法,结合区域地质背景分析,认为塔北西部地区和中东部地区的志留系柯坪塔格组砂岩物源明显不同。西部地区物源构造背景为大陆岛弧环境,物源物质为大陆上地壳,年代为元古代,推测物源区为塔北隆起;中东部地区物源构造背景为再旋回造山带环境,年代为奥陶纪,推测物源区为库鲁克塔格隆起带。物源母岩普遍含深成中酸性侵入岩。塔北西部物源距离远于塔北中东部地区,这对于恢复当时的沉积古地理环境以及塔里木盆地的类型和盆地演化有重要意义。
According to tile observation of petrographic thin sections, the approaches of the heavy mineralogy analysis and the analysis of SHRIMP U-Pb ages of detrital zircons, which is of the sandstone samples taken from the Dawangou outcrops of Keping area and the drill cores of TP3 ,TP7 and KQ1 in northern Tarim Basin, as well as using the classic Dickinson Ternary I）iagram method and combining with regional geology background analysis, we make a conclusion that the provenance of the sandstones in the Kepingtage Formation of Silurian in the west area of northern Tarim Basin is different from thai in the center and east area of northern Tarim Basin. The tectonic setting of the former provenance is tile continental island are environment, and it is composed of the materials from the Proterozoic upper crust. Thus the provenance is inferred to be Tabei uplift. However, the tectonic setting of the latter provenance is the recycled orogens environment and it is composed of the Ordovician materials. So, the provenance is inferred to be Kuluketage uplift. The type of provenance is widely igneous rock. Compared with the center and east area of northern Tarim Ba- sin, the west area is farther to the provenance. These conclusions are of great importance to the reconstruction of pa- leogeography deposition environment and the analysis of the type and evolution of Tarim Basin.
出处
《沉积学报》
CAS
CSCD
北大核心
2013年第3期421-429,共9页
Acta Sedimentologica Sinica
基金
国家973项目(编号:2011CB201100-03
2006CB202302)
国家重大专项(编号:2011ZX05005-004-Hz06
2011ZX05009-002)资助
关键词
塔北地区
柯坪塔格组
物源分析
锆石
SHRIMP
U-PB
定年
northern Tarim Basin
Kepingtage Formation
provenance analysis
SHRIMP U-Pb ages of detrital zir-cons
