辽宁桓仁—吉林通化地区中生代火山岩年代学研究

发布时间：2018-01-31 15:17

本文关键词： 火山岩地层学同位素年代学中生代地层辽宁桓仁－吉林通化地区　出处：《吉林大学》2015年硕士论文　论文类型：学位论文

【摘要】：作者通过两年的野外区域地质调查，观察了解辽宁桓仁-吉林通化地区地层单位间的接触关系，查明火山岩的地质特征及时空分布并建立地层层序。通过典型剖面研究，建立区域中生代火山岩多重地层划分与对比方案。同时，结合火山岩地球化学研究，探讨其形成的动力学背景及岩浆的源区、演化及与成矿作用的关系。野外调查采获了丰富的岩石、化石标本和同位素测试样品，获取了详实的实物资料和数据资料。研究工作为中生代地层划分与对比研究提供了新资料，为提高辽宁东部、吉林南部地区中生代研究水平及侏罗纪与白垩纪界限划分提供了实际资料。本文在广泛收集前人资料的基础上，对辽宁桓仁-吉林通化地区中生代地层中的火山岩研究现状及存在的问题进行了归纳和总结。在野外地质调查和综合分析前人资料的基础上，运用地层学、岩石学、古生物学及同位素年代学等多学科相结合的研究方法，重点对辽宁桓仁地区、吉林通化地区的中生代盆地中火山岩发育特征、时空分布及变化规律等进行了系统而深入的调查研究。在此基础上，通过各典型剖面介绍，对研究区的火山岩进行了划分与区域对比研究。依据地层之间的接触关系、古生物地层，并结合同位素年代学，对研究区中生代火山岩形成时代进行了确定。通过大量的高精度同位素测年结果可知，桓仁地区的小岭期火山岩年龄为129-124Ma；吉林通化地区果松期火山岩年龄为130-118Ma，林子头期火山岩年龄为129-121Ma。均形成于早白垩世，这与辽西地区的义县组火山岩年代学基本一致。通过对辽宁桓仁-吉林通化地区中生代地层中的火山岩研究，结合区域内火山岩年代学特征等。研究结果认为，依据岩石地层划分原则，将辽宁桓仁地区的中生代火山岩划归为小岭期和梨树沟期，分别对应小岭组和梨树沟组岩石地层单位，将吉林通化地区的中生代火山岩划归为果松期、林子头期和三棵榆树期，分别对应果松组、林子头组和三棵榆树组岩石地层单位。对研究区中生代火山岩区域对比研究表明，不同盆地火山岩发育程度均有所差异。即便是同一盆地的不同部位，无论是火山喷发期次、喷发强度，还是火山喷发物质等，均存在着不同的变化，其喷发间歇期的火山-沉积岩系的分布、化石产出层位等，也显示了较大的差异性。对研究区中生代火山岩典型剖面进行了较全面的介绍，并对主要火山岩岩石学特征进行了简介，，为同位素年代学研究打下了较好的基础。依据地层之间的接触关系、古生物地层，并结合同位素年代学，对研究区中生代火山岩形成时代进行了确定。通过大量的高精度同位素测年结果可知，桓仁地区的小岭期火山岩和吉林通化地区果松期、林子头期火山岩均形成于早白垩世，这与辽西地区的义县组火山岩年代学基本一致。依据生物地层特征，将梨树沟期和林子头期火山岩对应于义县组上部层位。
[Abstract]:Through two years of field regional geological survey, to investigate the contact relationship of strata unit in Liaoning Huanren - Jilin Tonghua area, find out geological characteristics and spatial distribution of volcano rock and established the stratigraphic sequence. Through the study on the typical section, the establishment of a regional Mesozoic volcano rock multiple stratigraphic division and correlation scheme. At the same time, combined with the study on the geochemistry of the rocks volcano. To investigate the dynamic background and magma source region of its formation, evolution and mineralization. The field survey collected rich rocks, fossils and isotope samples, obtain detailed data and real data. The research work for the Mesozoic stratigraphic classification and correlation study provides new data, in order to improve the eastern part of Liaoning in southern Jilin, and the research level of Mesozoic Jurassic and Cretaceous boundaries provide practical information.
Based on the extensive collection of previous data, and summarizes the research status of Liaoning Huanren - Jilin Tonghua volcano rock area in Mesozoic strata and the existing problems. In the field geological survey and comprehensive analysis of previous data on the basis of the stratigraphy, rock, paleontology and isotopic geochronology research methods and other disciplines the combination, focusing on the Liaoning Huanren area, the development characteristics of volcano rock in Jilin area of Tonghua basin in Mesozoic, temporal and spatial distribution and variation of the systematic and thorough investigation and study. On this basis, through the typical section, on the volcano rock was studied. Based on the contact relationship and regional division the formation, stratigraphic and paleontological, combined with isotopic geochronology of Mesozoic volcano rocks in the study area, the formation age were determined by high precision large amount of the same. Isotopic dating results, the Huanren area small Ling period volcano rock age 129-124Ma; Jilin Tonghua pine period volcano rock ages 130-118Ma, the head of woods volcano rock age 129-121Ma. were formed in the early Cretaceous, Yixian Formation in western Liaoning Province and the volcano rock chronology is basically the same.
Through to the Liaoning Huanren - Jilin Tonghua volcano rocks of Mesozoic strata in the study area, combined with regional characteristics. The chronology of volcano rock according to the research results, on the basis of the principle of lithostratigraphic division, Liaoning Huanren area of Mesozoic volcano rock into small Ling period and Lishugou period, corresponding to small Ling group and the Lishugou formation of rock strata the Jilin Tonghua area, Mesozoic volcano rock into pine woods, head and three elms, respectively corresponding pine group, woods head group and three group of lithostratigraphic units. The Elms of Mesozoic volcano rock regional comparative study, different volcano rocks in basin are different even. Different parts of the same basin, both the volcano eruption, eruption intensity, or volcano eruptions, there were different changes, the intermittent period of eruption of volcano sedimentary rock series of the Cloth, fossil horizon, also showed great differences. The typical section of Mesozoic volcano rocks in the study area are reviewed, and the main volcano rocks are introduced, a good foundation for the study of isotope chronology. Based on the contact relationship between strata, stratigraphic and paleontological. Combined with the isotope chronology, the Mesozoic volcano rock formation in the area were determined by age. A large number of high precision isotopic dating results, pinyon small age volcano rocks in Huanren area and Jilin area of Tonghua, the head of the woods volcano rocks were formed in the early Cretaceous, the Yixian Formation in western Liaoning Province and volcano rock chronology consistent. Based on the biological characteristic of strata, the Lishugou period and the period corresponding to the volcano rock forest head Yixian Formation of upper strata.

【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P588.14

【参考文献】