【作者】 刘卓；

【导师】 林晋炎；

【作者基本信息】 西北大学 ， 矿物学、岩石学、矿床学， 2011， 硕士

【摘要】 本文所研究的区域属于鄂尔多斯盆地东南部韩城华子山、河津西磑口地区以及邻区,构造上研究区地跨三个构造单元：渭北隆起、晋西挠褶带、陕北斜坡,研究的层位为下古生界地层(寒武系和奥陶系),属于海相碳酸盐岩沉积。通过对前人研究成果以及资料的整理和详细查阅,在大量的野外地质勘探、实测的基础上,细致的研究了研究区下古生界岩石学特征、地层特征、古生物特征、沉积相及岩相古地理特征等,并通过地球化学测试方法,对研究区华子山、西磑口两个典型剖面进行了采样,对其进行了碳酸盐岩的碳氧同位素的研究。研究区下古生界地层主要为碳酸盐岩—灰岩和白云岩,其中含较多的鲕粒灰岩、生物碎屑灰岩、竹叶状灰岩、鲕粒白云岩等,还有较少量的泥岩层以及石膏盐岩。鄂尔多斯东南部下古生界主要发育开阔海台地相、环陆含砂泥坪相、环陆泥云坪相、云灰坪相等沉积相类型,并对这些沉积相进行详述,并阐述了下古生代主要沉积演化特征。通过对陕西韩城华子山剖面以及山西河津西磑口剖面碳酸盐岩样的碳氧同位素的研究,陕西韩城华子山剖面寒武系碳酸盐岩氧同位素δ18O值分布区间为-10.19‰-5.65‰,碳同位素δ13C值分布区间为-2.58‰-0.69‰：山西河津西磑口剖面寒武系和奥陶系氧同位素δ18O值分布区间为-9.64‰--5.94‰,碳同位素δ13C值分布区间为-4.84‰-0.41‰。韩城华子山剖面在寒武系张夏组底部与张夏组顶部均有一次比较明显的碳氧同位素的正漂移,河津西磑口剖面在寒武系毛庄组与徐庄组的交界处、奥陶系马家沟组马一段与马二段交界处以及马六段均有一次比较明显的碳氧同位素正漂移。更多还原

【Abstract】 The study area of this thesis is located in the southern Ordos Basin, includes Han Cheng HuaZiShan, He Jin XiWeiKou, as well as its adjacency, and covers three tectonic zones, including Wei Bei uplift, Jin Xi fold belt, and Shan Bei slope, where the research formations belong to the lower Paleozoic erathem strata (Cambrian and Ordovician system), marine carbonate deposition. Based on sorting and access of previous research results, field geological prospecting, and actual measurement, a research in detail was made and concentrated in the petrological characteristics, strata characteristics, paleontology features, as well as the paleogeography features of sedimentary facies and lithofacies. Sampling was done in two typical profiles, Hua Zi Shan and Xi Wei Kou, which is in the research region, and the samples were analyzed using geochemical test method.The lower Paleozoic erathem strata in the study area were dominated by carbonate rocks-limestone and dolomite, and were rich in oolitic limestones, bioclastic limestone, wormkalk, as well as oolitic dolostone, with few mudstone layers and Gypsum halite. The sedimentary facies was mainly the upgrowth of open tableland facies, Ring lu Sandy shale, Ring lu Muddy dolostone, Dolomitic limestone, and so on. Those facies as well as evolution Characteristics of the deposition were discussed in this work.The result from the analysis on carbon and oxygen isotopes in Han Cheng Hua Zi Shan profile and He Jin Xi Wei Kou profile in Shanxi and Shaanxi province respectively, is:theδ18O andδ13C value in the carbonatite of Cambrian system in the former profile ranged from-l0.19‰to -5.65‰and -2.58%o to 0.69‰, respectively; The ratios in Cambrian and Ordovician system in the latter profile were -9.64‰--5.94‰and-4.84‰-0.41‰forδ18O andδ13C, respectively. A positive drift of oxygen isotopes was apparently observed at both the top and bottom of Zhang Xia Group in the Han Cheng Hua Zi profile, as well as at the border s between Mao Zhuang and Xu Zhuang Groups in Cambrian system, between the 1st and 2nd sections of Ma Jia Gou Group in Ordovician system, and in the 6th section.更多还原