【作者】 李磊；

【导师】 汤达祯； 刘清泉；

【作者基本信息】 中国地质大学（北京） ， 地质工程， 2010， 硕士

【摘要】 内蒙古丰镇市侯家营地区毗邻大同盆地,该区有含煤地层存在,具有聚煤潜力。本文应用单孔资料,借鉴国内外含煤盆地地层层序研究的方法,结合野外地质调查工作,系统分析了丰镇盆地含煤岩系的层序地层特征,并分析了层序地层的沉积环境和沉积相等;通过对孢粉样品的分析,研究了孢粉的地质时代,植物群的古气候、古生态和沉积环境;采用地震方法研究了含煤地层的赋存形态和赋存范围。1、根据古运动面和侵蚀面将丰镇盆地含煤岩系划分为一个超层序和两个层序,而后根据盆地构造演化特点和岩性特征划分出了湖泊初始泛面、最大湖泛面和湖泊基本消亡面,并根据这三个界面,结合丰镇盆地含煤地层的岩性特征,将丰镇盆地含煤岩系层序的沉积体系域划分为低水位体系域、湖泊扩展体系域、湖泊萎缩体系域和非湖泊体系域。2、根据丰镇盆地岩层的层序地层特征结合区域地质背景得出:丰镇盆地主要聚煤环境为滨湖聚煤、泥炭沼泽聚煤和河流聚煤。具有工业价值的煤层主要形成于湖泊萎缩体系域,即主要含煤地层为大同组上段,云岗组几乎不含具有工业价值的煤层,或只含较薄煤层甚至煤线。3、通过对孢粉的分析研究发现:孢粉1和孢粉2为早白垩世的产物,孢粉3为侏罗纪产物。由此研究推断,早白垩世和侏罗纪丰镇地区的气候为热带或亚热带、温带潮湿气候,适宜大量植物的繁殖。4、应用地震方法研究了盆地内含煤岩系的赋存形态及范围。丰镇盆地主要含煤岩系大同组在整个盆地内都有分布,含煤地层侏罗纪下大同组的标高约550 m～1350 m,标高最低位于D2线与D3线之间地段,约550 m,最高位于赋存区边界上,约1350 m。地层倾角约1°～17°,H2-1钻孔附近地段地层倾角最小,约1°,赋存区西北部地段地层倾角最大,约17°。5、应用地震方法同时对盆地内的构造进行了系统分析。丰镇盆地内断裂构造较为发育,预查区共解释断点12个,根据本区地质规律组合正断层4条,均为可靠断层,孤立正断点2个,按照由南向北、由西向东的顺序加以命名,分别为DF1～DF4正断层,f1、f2正断点。6、通过对单个钻孔资料和地震资料的分析研究表明,云岗组虽然在整个盆地内都有分布,但不含或含有煤线和薄煤层,没有工业价值的煤层,故不应为今后煤炭勘探的目标地层。大同组在整个盆地内广泛分布,从沉积环境、古气候和古构造等方面都具备形成具有工业价值煤层的条件,因此,今后丰镇盆地内今后煤炭勘查的重点应为大同组含煤岩系。更多还原

【Abstract】 There are coal-bearing strata and coal-accumulating potential in Houjiaying areas of Fengzhen City in Inner Mongolia Autonomous Region,which is adjacent to the Datong Basin. Based on borehole data in study area, a lot of sino-foreign methods of coal-bearing basin stratigraphy research and investigation of field geology, this paper analyzes the sequence stratigraphic characteristics, the depositional environment and sedimentary facies of Fengzhen basin; according to the analysis of pollen samples, the geological age of pollen samples ,the flora of the ancient climate and palaeoecology and depositional environment of the flora were discussed; using the Seismic Exploration Method, we studied the spatial distribution and range of the bearig-coal formation.1、Based on the paleo-movement surface and regional erosion surface, coal measures in Fengzhen Basin could be divided into 1suppersequence and 2 sequences. Taking the characteristics of the basin structural evolution and lithology into account, the initial lake flooding surface, largest lake-flooding surface and terminal lake-flooding surface are subdivided. Combined with the above-mentioned three boundaries and the lithologic characteristics of coal-bearing strata, the deposit systems of coal-bearing sequence in Fengzhen basin could be divided into lowstand system tract, lacustrine extend system tract, lacustrine wrinkle system tract and non- lacustrine system tract.2、According to the characteristics of sequence stratigraphy and regional geology background, study shows: the favorable environments of forming coal measures are lakeshore swamp, peat swamp and flood plane deposit. The major coal-bearing strata is upper of Datong formation, which belongs to the lacustrine wrinkle system tract and be with commercially valuable. While, Yungang formation only contains thin coal seam, without commercially valuable coal.3、It is found through the analysis of palynomorph that both No.1 and No.2 palynomorph are the products in Early Cretaceous, and No.3 is the product in Jurassic. Therefore, it can be concluded that the weather in Fengzhen region of Early Cretaceous and Jurassic was tropical, subtropical or temperate which was suitable for the propagation of plenty of plants.4、The pattern and range of the coal-bearing strata in Fengzhen Basin is studied by using seismic method. The main coal-bearing strata of the basin are Datong Group, which are distributed throughout the whole basin. The elevation of Datong Group, the coal-bearing strata under the Jurassic, is about 550~1350m. The lowest elevation is located between line D2 and line D3 which is around 550m. The highest elevation is near boundary of the coal-bearing strata is about 1350m. The range of the stratigraphic dip of the study area is about 1°~17°. Moreover the stratigraphic dip near borehole H2-1 is smallest, which in the northwest is largest.5、The research analyzed the structure of the basin using the method of seismic. The faults are more developed in Fengzhen basin, and the essay explained 12 Breakpoint in the pre-inspection districts. According to the law of geological, there are 4 normal faults and 2 isolated breakpoint in this area, Named from south to north and from west to east, They are DF1 ~ DF4 normal faults respectively, and f1, f2 breakpoints.6、Based on drilling data and seismic profiles, it shows that there are no coal seam of industrial value and just coal seam lines and thin coal beds in formation of Yungang Group, thought it is distributed throughout the whole basin; it should not for the future exploration of coal target formation. Tatung Group is widely distributed throughout the basin, which is with the conditions for the formation of industrial value of the coal seam considering the characteristic of sedimentary environment, paleoclimate and structure evolution. Therefore, the coal exploration targets in Fengzhen basin should focus on the future of coal beds of Datong group.更多还原