【作者】 欧阳京；

【导师】 王金荣；

【作者基本信息】 兰州大学 ， 矿物学、岩石学、矿床学， 2010， 硕士

【摘要】 西准噶尔地区隶属于中亚造山带,其位于阿尔泰造山带和天山造山带两个次一级造山带之间,归属于古生代的大陆增生褶皱区,主要由华力西期褶皱山系组成。研究区位于准噶尔盆地西北部,出露的地层不全。本文是在扎实的野外地质矿产调查工作及翔实的室内资料分析基础上,采用地质学综合研究法,利用区域地层、火山旋回及岩石学特征对西准噶尔托里县老风口地区地层进行了清理。在此基础上结合各组岩石粒度分析数据、古生物化石及侵入岩年龄数据对西准噶尔托里县老风口地区地层的沉积-构造背景进行了系统的研究,取得了一些新认识,为西准噶尔沉积构造演化的深入研究提供重要的科学依据,研究结果表明：(1)马拉苏组(D1ml)：通过侵入该组的阿克乔克岩体二长闪长斑岩锆石U—Pb年龄(410.5±2.9Ma)和色尔登岩体二长花岗岩锆石U—Pb年龄(309.9±2.4Ma)分析,马拉苏组沉积时代早于阿克乔克岩体二长闪长斑岩形成时代(410.5±2.9Ma)；结合火山地层和火山喷发旋回特点,并与区域地层对比分析,可知该地层归属于早泥盆世。该时期火山活动由弱变强,在研究区就地形成了一套以火山碎屑岩为主,夹少量的安山质火山熔岩的火山岩建造；同时岩石粒度数据、古生物化石特征表明,该区域当时属于浅海相环境,火山活动由弱变强。(2)库鲁木迪组(D2k)：通过侵入该组的哈图岩体二长花岗岩锆石U—Pb年龄(319.6±3.2Ma)分析,库鲁木迪组沉积时代早于哈图岩体二长花岗岩形成时代(319.6±3.2Ma)；结合火山地层和火山喷发旋回特点,并与区域地层对比分析,可知该地层归属于中泥盆世。该时期火山活动具有由强→弱→强的特点,在研究区就地形成了一套以火山碎屑岩为主夹少量的安山质熔岩的火山岩建造；同时岩石粒度数据表明,该区域当时属于浅海相环境。(3)姜巴斯套组(C1j)：通过火山地层和火山喷发旋回特征分析,并与区域地层对比分析,该地层归属于早石炭世。该时期火山活动微弱,在研究区就地形成了一套以火山碎屑岩为主,夹少量的火山熔岩的火山岩建造；同时结合岩石粒度数据、古生物化石特征表明,该区域当时属于浅海相环境。更多还原

【Abstract】 The West Junggar region, belonging to the Central Asian orogenic belt, is located between the secondary orogenic belts of the Altai and Tianshan orogenic belts.The West Junggar region attributes to the Paleozoic continental accretion fold zone and mainly be formed by the Variscan fold system. The study area is located in the northwestern Junggar basin and the strata exposed incomplete. This paper is to compile the strata in Tuoli County, West Junggar according to the solid field geology and mineral resources investigation, the indoor detail analysis of data, regional stratums, the characteristic of volcanic cycle and the characteristic of petrology. Combined with the data of size analysis from rocks, fossils and age of intrusive rocks in the West Junggar Toli County, a systematic study on the tectonic setting and sedimentary environment in the old outlet of strata has been carried out, and some new understanding has been made, which provides important scientific basis on in-depth study of sedimentary in the West Junggar. The results show that:(1) Malasu group (D1ml):Through the analysis of the zircon U-Pb ages of monzodiorite porphyry in the Akeqiaoke rock body(410.5±2.9Ma) and those of monzogranite in Seerdeng rock body (309.9±2.4Ma), which both invaded the Malasu group, the sedimentary age of Malasu group was earlier than the formation age of monzodiorite porphyry in the Akeqiaoke rock body(410.5±2.9Ma); Combined with volcanic formation, the characteristics of volcanic eruption cycle, and the regional stratigraphic correlation, it showed that the strata is in the Early Devonian. Volcanic activity in this period was from weak to strong; and it showed that this region belonged to shallow marine environment at that time on the basis of rock grain size data and fossils feature.(2) Kulumudi group (D2k):Through the analysis of the zircon U-Pb ages of monzogranite in Hatu rock body (319.6±3.2Ma), which invaded the Kulumudi group, the sedimentary age of Kulumudi group was earlier than the formation age of monzogranite in the Hatu rock body(319.6±3.2Ma); Combined with volcanic formation, the characteristics of volcanic eruption cycle, and the regional stratigraphic correlation, it showed that the strata is in the Middle Devonian. Volcanic activity in this period was from strong to weak to strong, and it formed a series of volcanic construction, which was pyroclastic rocks mainly, clipping a small amount of andesitic volcanic lava; and it showed that this region belonged to shallow marine environment at that time on the basis of rock grain size data.(3) Jiabasitao group (C1j):Combined with volcanic formation, the characteristics of volcanic eruption cycle, and the regional stratigraphic correlation, it showed that the strata is in the Early Carboniferous.Volcanic activity in this period was weak, and it formed a series of volcanic construction, which was pyroclastic rocks mainly, clipping a small amount of andesitic volcanic lava; and it showed that this region belonged to shallow marine environment at that time on the basis of rock grain size data and fossils feature.更多还原