六盘山地区及邻区中新元古代构造类型及其动力学环境研究

发布时间：2018-05-26 17:34

本文选题：六盘山地区及邻区 + 中上元古界　；参考：《西安石油大学》2015年硕士论文

【摘要】：六盘山地区及邻区位于鄂尔多斯地区西南部,区内中上元古界不整合覆盖于吕梁运动固结的克拉通结晶基底之上,中上元古界分布广泛,无明显变质。随着国内外中上元古界油气藏及鄂尔多斯盆地西南缘崇信县蓟县系沥青的发现,使得六盘山地区及邻区中上元古界日益成为一个值得关注的油气勘探领域。由于以往该区油气勘探侧重于中古生界,对该区中上元古界的各项研究甚少,致使对该区中上元古界的盆地构造属性认识存在分歧,研究十分薄弱。本文在系统整理、总结前人研究成果的基础上,通过野外考察、剖面实测,辅以分析测试,结合测井数据和地震大剖面等资料,对研究区中上元古界地层划分与分布特征、构造沉积特征及其演化进行了综合研究。取得了以下认识:(1)综合分析锆石U-Pb年龄测试及前人研究成果的基础上,确定黄旗口组属于长城系,王全口组属于蓟县系。(2)运用测井、地震及地化测试资料,结合野外观察、镜下鉴定等成果,对研究区中上元古界沉积相及沉积环境进行了分析,结果显示:黄旗口组早期为裂谷期冲积扇相沉积,晚期变为河流-滨岸相沉积;王全口组为裂谷后的潮坪相沉积;正目观组为滨海-冰川相沉积。(3)中新元古代,六盘山地区及邻区大规模裂陷解体,区域整体处于地壳伸展的构造背景,陆内裂谷、陆缘裂谷的构造组合为其基本特征,随后发育了裂谷环境下的长城系黄旗口组和稳定环境下的蓟县系王全口组。
[Abstract]:The Liupanshan area and its adjacent area are located in the southwest of Ordos area. The middle and upper Proterozoic unconformity covers the craton crystalline basement of Lv Liang movement consolidation, and the middle and upper Proterozoic is widely distributed without obvious metamorphism. With the discovery of middle and upper Proterozoic reservoirs at home and abroad and the discovery of Jixian system asphalt in Chongxin County southwest margin of Ordos Basin the Middle and Upper Proterozoic in Liupanshan area and its adjacent areas has become an increasingly noteworthy oil and gas exploration field. In the past, oil and gas exploration in this area focused on the Middle Paleozoic and there were few studies on the Middle and Upper Proterozoic in this area, which resulted in different understanding of the basin tectonic attributes of the Middle and Upper Proterozoic in this area, and the study was very weak. On the basis of systematical arrangement and summing up the previous research results, this paper classifies and distributes the middle and upper Proterozoic strata in the study area through field investigation, section measurement, analysis and test, well logging data and seismic large section. The tectonic sedimentary characteristics and their evolution are comprehensively studied. Based on the comprehensive analysis of zircon U-Pb age test and previous research results, it is determined that the Huangqikou formation belongs to the Great Wall system, and the Wangquankou formation belongs to Jixian system. The sedimentary facies and sedimentary environment of the middle and upper Proterozoic in the study area are analyzed under microscope. The results show that the Huangqikou formation was alluvial fan facies in the rifting period and fluvial shore-shore facies in the late stage; The Wangquankou formation is the tidal flat facies behind the rift and the Zhengmu formation is the littoral glacial facies deposit. (3) the Mesoproterozoic, the Liupanshan area and its adjacent area are disintegrated, and the whole area is located in the tectonic setting of crustal extension and intracontinental rift. The tectonic assemblage of the continental margin rift is its basic feature, and the Great Wall system of Huangqikou formation and the Jixian system of Wangquankou formation in stable environment are developed in the rift environment.
【学位授予单位】：西安石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13;P548

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