松辽盆地白垩系营城组—嫩江组离子探针锆石U-Pb定年
发布时间：2018-12-21 19:33
【摘要】：松辽盆地作为我国最大陆相盆地,具有完整的白垩纪陆相地层序列。松辽盆地嫩江组以其发育巨厚的烃源岩及具有最大湖侵事件、CNS的结束等记录而受到广泛关注,前人仅在嫩二段底部获得一个同位素年龄值,嫩江组/姚家组界线是盆地最大湖侵及海侵事件的开始时间,由于缺乏精确的同位素年龄值,该年龄还处于争论之中;营城组发生了两次较大的火山运动事件,是东北亚地区晚中生代岩浆作用的重要组成部分,厘定营城组的火山运动事件的活动时限对正确认识区域构造-岩浆事件的变化规律,以及进一步的探讨区域地球动力学过程具有十分重要的意义。随着松科1井综合地层学的开展,松辽盆地晚白垩世年代地层学工作已经完成,而松辽盆地早白垩世的年代地层学工作有待于松科2井的进行而开展,完善松辽盆地白垩纪地层的年代学工作,为盆地其他地层工作提供基础年代学数据,并有助于将白垩纪陆相地层与海相地层进行对比。实施松科2井钻探的主要目的是揭露松辽盆地下白垩统至基底地层。“松科2井东孔”以松辽盆地早白垩世地层为取心目的层,目前已获得嫩江组一段、二段、登娄库组下部、营城组三四段以及沙河子组的部分岩心,为本文提供了绝佳的研究材料。本文以松辽盆地内松科2井和X1-4井以及岳王城剖面和姚家车站剖面为研究对象,在嫩江组和营城组采取了6个火山岩样品进行SIMS锆石U-Pb定年,获得了部分重要地层单位的界线年龄,结果显示:(1)嫩江组一段和嫩江组二段界线年龄为83.1Ma-83.5 Ma;姚家组二、三段和嫩江组一段的界线年龄为85.1 Ma-85.5 Ma之间;(2)营城组三段最下部的火山岩年龄为111.7 Ma。这些年龄为松辽盆地嫩江组下部提供了准确的年代学制约,为嫩江组下部构造运动时间、CNS的结束、最大湖侵事件提供了重要的年代学制约;为营城组年代学工作和对比标准提供基础数据,为中国陆相白垩纪地层重大地质事件的研究以及与全球白垩纪事件之间对比提供了精确地年龄依据。
[Abstract]:As the largest continental basin in China, Songliao Basin has a complete sequence of Cretaceous continental strata. The Nenjiang formation in Songliao Basin has received extensive attention due to its extremely thick source rocks and records of the largest lacustrine transgression events, the end of CNS, etc. Only one isotopic age value was obtained at the bottom of the second member of the Nenjiang formation in Songliao Basin. The boundary between Nenjiang formation and Yaojia formation is the beginning time of the largest lake transgression and transgression in the basin. Due to the lack of accurate isotopic age, the age is still in dispute. Two large volcanic events occurred in Yingcheng formation, which are an important part of late Mesozoic magmatism in Northeast Asia. Determining the time limit of volcanic movement events in Yingcheng formation can correctly understand the variation law of regional tectonic-magmatic events. And further study of regional geodynamic processes is of great significance. With the development of Synthetical stratigraphy in well Songke 1, the late Cretaceous chronostratigraphy in Songliao Basin has been completed, while the chronostratigraphy of early Cretaceous in Songliao Basin needs to be carried out in Songke2 well. To improve the chronology of Cretaceous strata in Songliao Basin, to provide basic chronological data for other stratigraphic work in the basin, and to help the Cretaceous continental strata and marine strata to be correlated. The main purpose of drilling well Songke 2 is to expose the Lower Cretaceous to basement strata in Songliao Basin. Taking the early Cretaceous strata of Songliao Basin as the formation of the east hole of Songke 2 well, the first and second member of Nenjiang formation, the lower part of Denglouku formation, the third and fourth member of Yingcheng formation and part of the core of Shahezi formation have been obtained. It provides excellent research materials for this paper. In this paper, taking Songke 2 well and X1-4 well in Songliao Basin as research objects, six volcanic rock samples were taken from Nenjiang formation and Yingcheng formation for SIMS zircon U-Pb dating. The boundary ages of some important stratigraphic units have been obtained. The results show that: (1) the boundary ages of the first and second sections of the Nenjiang formation and Nenjiang formation are 83.1Ma-83.5 Ma;. The boundary ages of the second, third and the first member of the Yaojia formation and the Nenjiang formation are between 85.1 Ma-85.5 Ma and (2) the lowest volcanic age of the third member of the Yingcheng formation is 111.7 Ma.. These ages provide accurate geochronological constraints for the lower part of the Nenjiang formation in Songliao Basin, and provide important geochronological constraints for the tectonic movement time of the lower part of the Nenjiang formation, the end of CNS, and the maximum lacustrine transgression event. It provides basic data for geochronological work and correlation standard of Yingcheng formation, and provides an accurate age basis for the study of major geological events in the continental Cretaceous strata in China and the correlation between them and the global Cretaceous events.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P597.3;P534.53
，
本文编号：2389360
[Abstract]:As the largest continental basin in China, Songliao Basin has a complete sequence of Cretaceous continental strata. The Nenjiang formation in Songliao Basin has received extensive attention due to its extremely thick source rocks and records of the largest lacustrine transgression events, the end of CNS, etc. Only one isotopic age value was obtained at the bottom of the second member of the Nenjiang formation in Songliao Basin. The boundary between Nenjiang formation and Yaojia formation is the beginning time of the largest lake transgression and transgression in the basin. Due to the lack of accurate isotopic age, the age is still in dispute. Two large volcanic events occurred in Yingcheng formation, which are an important part of late Mesozoic magmatism in Northeast Asia. Determining the time limit of volcanic movement events in Yingcheng formation can correctly understand the variation law of regional tectonic-magmatic events. And further study of regional geodynamic processes is of great significance. With the development of Synthetical stratigraphy in well Songke 1, the late Cretaceous chronostratigraphy in Songliao Basin has been completed, while the chronostratigraphy of early Cretaceous in Songliao Basin needs to be carried out in Songke2 well. To improve the chronology of Cretaceous strata in Songliao Basin, to provide basic chronological data for other stratigraphic work in the basin, and to help the Cretaceous continental strata and marine strata to be correlated. The main purpose of drilling well Songke 2 is to expose the Lower Cretaceous to basement strata in Songliao Basin. Taking the early Cretaceous strata of Songliao Basin as the formation of the east hole of Songke 2 well, the first and second member of Nenjiang formation, the lower part of Denglouku formation, the third and fourth member of Yingcheng formation and part of the core of Shahezi formation have been obtained. It provides excellent research materials for this paper. In this paper, taking Songke 2 well and X1-4 well in Songliao Basin as research objects, six volcanic rock samples were taken from Nenjiang formation and Yingcheng formation for SIMS zircon U-Pb dating. The boundary ages of some important stratigraphic units have been obtained. The results show that: (1) the boundary ages of the first and second sections of the Nenjiang formation and Nenjiang formation are 83.1Ma-83.5 Ma;. The boundary ages of the second, third and the first member of the Yaojia formation and the Nenjiang formation are between 85.1 Ma-85.5 Ma and (2) the lowest volcanic age of the third member of the Yingcheng formation is 111.7 Ma.. These ages provide accurate geochronological constraints for the lower part of the Nenjiang formation in Songliao Basin, and provide important geochronological constraints for the tectonic movement time of the lower part of the Nenjiang formation, the end of CNS, and the maximum lacustrine transgression event. It provides basic data for geochronological work and correlation standard of Yingcheng formation, and provides an accurate age basis for the study of major geological events in the continental Cretaceous strata in China and the correlation between them and the global Cretaceous events.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P597.3;P534.53
，
本文编号：2389360
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