【作者】 郑庆荣；

【导师】 刘鸿福；

【作者基本信息】 太原理工大学 ， 矿产普查与勘探， 2012， 博士

【摘要】 大陆地壳是研究地球演化的重要对象,陆壳的生成和演化与板块构造的关系是板块构造研究中的重大前沿课题。山西中北部在大地构造上处于特殊位置,东部为太行山板内造山带,东北部紧靠燕山板内造山带的南端,北部与华北北缘板内活动带相距不过百余公里,西部是华北克拉通稳定地块鄂尔多斯盆地,区内地层出露较齐全,构造形迹复杂,岩浆活动频繁,成矿作用明显,保留了陆壳演化各个时期的信息,是研究陆壳演化的良好之地。本文以“沉积地层为格架,岩浆活动为指征,构造演变为背景”进行相互印证和综合分析,总结了“山西中北部陆壳演化模式”,有助于提高对区内陆壳形成演变的认识,有助于提高对华北克拉通形成、演化、破坏过程的了解。对山西中北部沉积地层建造序列、岩浆建造序列和构造格局演化序列的深入分析,厘定了研究区陆壳形成演化阶段与演化期,总结和归纳了形成演化过程,建立了形成演化的模式,取得了一些新的认识。论文对7条地层剖而进行了野外观察,选取其中4条进行实测,建立了地层柱状图,厘清区内沉积建造序列：基底、盖层、松散沉积物三套序列特征鲜明。同时重点对中生代宁静盆地沉积地层进行了系统测量、重点取样和室内分析,发现从侏罗纪开始古流向有部分时期显示向东南流动,记录了宁静盆地西部开始隆升的信息,提出中生代吕梁山北段隆起的时限应该不晚于中侏罗世大同组时期的认识。这对进了步认识中生代山西板块乃至华北盆地演化的过程有重要意义。岩浆建造序列的厘定选取区内各个时期的岩浆岩体进行考察,野外考察9个不同时期的岩浆岩体,五台期、吕梁期、燕山期和喜山期的岩浆活动各有特点,受构造背景控制明显。重点对其中2个进行深入研究,使用野外填图、系统采样、镜下观察、化学分析、锆石测年等综合手段对茶房口—居十山岩体进行的专题研究,研究表明居士山岩体与新发现的茶房口岩株群形成于1786-1797Ma时期,应属于吕梁期的产物,纠正了前人认为居士山岩体是中生代燕山期产物的错误认识,地球化学分析显示居士山岩体与茶房口岩株群属于同源产物,推测应属于同一岩体的分枝,可称为茶房口—居士山岩体,新的结论对认识系舟山断褶带地区岩浆活动具有重要意义。对繁峙玄武岩进行的针对性研究显示北部熔浆向北流动,而南部流向南方,表明溢流通道应在滹沱河新裂陷河谷,为前人的推测找到了确证。岩石地球化学分析还显示：繁峙玄武岩岩石系列为碱性玄武岩系列,具有大陆裂谷型火山岩的特征,岩石中发育橄榄石包裹体,表明岩浆来源于上地幔,为研究华北克拉通破坏提供了参考。区内构造格局的演变序列由分析形变特征、形变序列与成生联系进行厘定,基底构造格局呈残留状态,分布局限；中生代构造格局控制了区内现今地貌分布状态；新生代叠加在中生代格局之上。三个阶段的构造格局均体现了动力背景的转换过程,是划分区内陆壳演化阶段的重要依据。论文提出建立山西中北部陆壳演化模式的三个原则：建造连续的原则,改造鲜明的原则,动力背景一致的原则。应用综合归纳分析建立模式的三种途径：地层接触关系的剖析,沉积建造与岩浆建造的剖析,形变特征、形变序列与成生联系的剖析,将演化过程分为3个阶段：基底形成阶段、盖层发展阶段和改造破坏阶段；进一步细分为7个演化期,从老到新依次为：陆核形成期、陆块碰撞期、基底改造期、盖层形成期、盖层发展期、挤压改造期和拉张破坏期。总结建立了山西中北部陆壳演化模式,该模式的建立对研究山西中北部区域地质演化具有重要意义。更多还原

【Abstract】 The continental crust is an important object of study the Earth’s evolution, the relationship between the formation and evolution of continental crust and the plate tectonics is the major frontier in the study of plate tectonics. The north-central Shanxi is located in a very special tectonic position, eastern part of which is the Taihang Mountain intraplate orogen belt, northeast part is close to the southern tip of the Yanshan intraplate orogenic belt, northern part is more than a hundred kilometers away from the northern margin of North China intraplate mobile belt and the western part is Ordos Basin, which is a stable block within North China Craton. For the complete strata outcrops, complex structural features, frequent magmatic activities and the obvious mineralization, the study area retains information of the evolution of continental crust during different periods and is a better place for researching continental crust evolution.Based on "sedimentary strata as frame, magmatic activity as indications, tectonic evolution as background", this paper confirms and comprehensively analyses the above-mentioned, and summarizes "the evolution model of continental crust of north-central Shanxi", which will help to improve the understanding of the formation and evolution of Shanxi plate and the process of the formation, evolution and destruction of the North China Craton.Through the intensive analysis of sedimentary strata construction sequence, the sequence of magmatic activity and the evolution of tectonic pattern, this paper determines the stage of its formation and the evolution period, summarizes and concludes the process of the formation and evolution of continental crust, and builds the model of formation and evolution.According to thinking about the founding of evolution model of the continental crust, this paper proposes three principles of founding the model of the study area(principle of continuous construction, distinct transformation and consistent dynamic background)and concludes and analyses comprehensively three ways of model-founding(analysis of the stratigraphic contact, sedimentary formation and magmatic formation, characteristics and sequence of deformation and the genetic relation), which helps developing new ideas and methods for the regional geological research.The paper chooses4strata sections for measuring from7field observation strata sections, builds strata column, determinates sedimentary formation sequence, in which basement, cap rocks, unconsolidated sediments, have distinctive sequence feature. And through the in-depth research, including field observation, systematical measurement, focused sampling and laboratory analysis, on the Mesozoic sedimentary strata of the Ningjing basin it has been found that from Jurassic Datong groups began to show the paleocurrent flowed to the southeast at some period, recording the information of uplift of western Ningjing Basin and propose the conclusion that the time of uplift of Northern Lvliangshan Mountain during the Mesozoic shouldn’t be later than the Middle Jurassic Datong group. This new understanding will contribute to a better understanding of the evolution of Shanxi plate and North China basin during Mesozoic.Author Chooses different period magmatic rocks for investigating in order to dominate magmatic and structure sequence. After investigates9different period magmatic rocks which is Wutainian, Lvliang, Yanshanian and Himalayan. period, and founds their magma activity character and them been controlled by tectonics. By the end focused on2magmatic rocks for deeply researching. Author found that the formation period of Jushi mountain rock mass and Chafangkou stock group is1786Ma～1797Ma which belongs to Luliang period through field mapping、systematic sampling、observed by microscope、chemical analysis、zircon dating etc comprehensive means, corrected the wrong recognition that Jushi mountain rock mass is the production of Yanshan period of Mesozoic. Geochemical analysis shows that Jushi mountain rock mass and Chafangkou rock mass group are homologous, and conjecturing they are two branches of the same rock mass which is named Chafangkou-Jushi mountain rock mass. The new conclusion has important significance for the understanding of fault-fold belt magmatic of Xizhou Mountain. A focused investigation was done to Fansi basalt through outside investigation、field observation comparison sampling、chemical analysis etc. Study shows that the northern magma flew to the north while the southern to south which shows that the outpouring channel is in the rift valley of Hutuo River and found an evidence for the conjecture of previous. The rock geochemistry analysis also shows that Fanshi basalt belongs to alkaline basalt series and has the characteristics of continental-rift type volcanic, olivine inclusions growth in rock indicate that the magma came from upper mantle, and provide references for the research of north china craton.By determining deformation characteristics, deformation sequence and formation relation, author obtains evolution sequence of the structure pattern and residual state of basement structure pattern and distribution limitations. Mesozoic tectonic pattern controlled the region today landforms distribution. Cenozoic superimposed on top of the Mesozoic pattern. The three stages of the tectonic pattern reflect the dynamic background of the conversion process, and it is an important basis of the divided district inland crustal evolution stage.This paper proposes three principles of founding the model of the study area (principle of continuous construction, distinct transformation and consistent dynamic background) and concludes and analyses comprehensively three ways of model-founding (analysis of the stratigraphic contact, sedimentary formation and magmatic formation, characteristics and sequence of deformation and the genetic relation). The evolution process was divided into three stages: basement-forming stage、cover development stage and transformation-destruction stage; and a further divided into7evolution stages which are continental nucleus formation stage、landmass collision stage、 basement transformation stage、cover formation stage、cover development stage、 extrusion transformation stage and tension destruction stage. The continental formation evolution model of north central Shanxi was constructed through summary and the built of this model provides references for the geological evolution of north central Shanxi.更多还原