新疆巴里坤下涝坝—石灰窑一带泥盆系特征研究

发布时间：2018-06-29 12:56

本文选题：泥盆系特征 + 沉积环境　；参考：《长安大学》2015年硕士论文

【摘要】：本文以新疆巴里坤下涝坝-石灰窑一带的泥盆系作为研究对象,在广泛收集前人成果资料的基础,经过充分的野外考察和室内综合分析对研究区泥盆系分布、层序、地层单元划分、岩石组合、接触关系、古生物化石、火山岩及地球化学特等基本特征进行了系统的研究,取得以下的认识:1调查区内泥盆系发育有下泥盆统大南湖组(D1d)和上泥盆统康古尔塔格组(D3kg),大南湖组与下覆奥陶系庙尔沟组为不整合接触;与上覆康古尔塔格组为不整合接触;其间缺失中泥盆统。上泥盆统康古尔塔格组与上覆下石炭统黑山头组为整合接触。表明在研究区泥盆纪地层发育与天山南侧的土哈盆地的泥盆系有明显的不同。2上泥盆统康古尔塔格组的岩石特征在调查区东西部具有明显的的变化,东部正常沉积碎屑岩较少,火山岩多,中部出现火山岩,西部以正常沉积碎屑岩为主。根据这个现象可以判断出,晚泥盆世调查区内由西向东火山活动呈增强的趋势。3.通过对下泥盆统大南湖组的岩石成分、层理构造、火山碎屑等特征等研究,揭示出大南湖组底部至中部的沉积地层显示出一个海退序列。而该组上部主要为一套火山碎屑岩夹少量火山碎屑沉积岩及中基性火山岩,通过岩石化学等分析判断该段火山岩的喷发环境应该是洋岛环境。4.通过对新疆八里坤下涝坝-石灰窑一带泥盆纪地层的变质变形特征和接触关系的研究,划分出早泥盆是构造层和晚泥盆世-早石炭世的构造。
[Abstract]:In this paper, the Devonian system in the area of Xiwei-Ba-Lime Kiln, Balikun, Xinjiang, is taken as the research object. On the basis of extensive collection of previous data, the distribution and sequence of Devonian system in the study area are studied through full field investigation and indoor comprehensive analysis. The basic characteristics of stratigraphic unit division, rock assemblage, contact relationship, paleontological fossils, volcanic rocks and geochemistry are systematically studied. The following understandings were obtained: the Devonian developed in the area of 1: 1: lower Devonian Dannanhu formation (D1d) and Upper Devonian Kangguertag formation (D3kg), the Dananhu formation and the Lower Ordovician Miaoergou formation were unconformable contacts, and the upper Devonian Kangguertag formation was unconformable contact with the upper Devonian Kangguertag formation, and the lower Ordovician Miaoergou formation was unconformable contact with the upper Devonian formation. The middle Devonian system is missing. The upper Devonian Kangguertag formation and the upper Carboniferous Keshantou formation are integrated contact. It shows that the Devonian stratigraphic development in the study area is obviously different from that in the Tuha basin on the south side of Tianshan Mountains. 2. The rock characteristics of the upper Devonian Kangguertag formation have obvious changes in the east and west of the investigation area, and the normal sedimentary clastic rocks in the eastern part of the study area are less. There are many volcanic rocks, there are volcanic rocks in the middle, and normal sedimentary clastic rocks dominate in the west. According to this phenomenon, the late Devonian survey area shows an increasing trend of volcanic activity from west to east. Based on the study of the rock composition, bedding structure and pyroclastic characteristics of the Dananhu formation in the Lower Devonian, it is revealed that the sedimentary strata from the bottom to the middle of the Dananhu formation show a regressive sequence. The upper part of the group is mainly composed of a set of pyroclastic rocks with a small amount of pyroclastic sedimentary rocks and medium-basic volcanic rocks. The eruption environment of the volcanic rocks in this section should be oceanic island environment by petrochemical analysis. Based on the study of the metamorphic deformation characteristics and contact relationship of Devonian strata in the area of Xianwei-Ba-Liyao in Balikun, Xinjiang, it is concluded that the early Devonian is a tectonic layer and the late Devonian to early Carboniferous structure.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P534.4

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