鄂尔多斯盆地西缘南段马家滩构造区带的形成演化机制研究

发布时间：2018-06-13 16:32

  本文选题：马家滩构造区带 + 平衡剖面　； 参考：《西北大学》2017年硕士论文

【摘要】：马家滩构造区带位于贺兰—银川伸展构造系、六盘山冲断构造系以及鄂尔多斯地块之间,处于极其特殊的构造位置,其形成演化是与周围各构造单元相互作用的结果,对马家滩构造区带形成演化机制的研究具有重要的区域构造意义。前人在马家滩构造区带取得了许多成果及认识,其大型滑脱面之上的逆冲推覆构造样式已经得到多数学者的认可,但对其形成演化机制尚不清楚,需要进一步的深入研究。为了认识马家滩构造区带的形成演化机制,首先通过马家滩构造区带及邻区印支期以来主要不整合面的分析,结合前人低温热年代学、沉积学等方面的研究成果,限定了马家滩构造区带及邻区主要构造变形的发生时间。然后对穿过马家滩构造区带的四条地震剖面进行时深转换、剥蚀量恢复及平衡剖面反演模拟,分析出了马家滩构造区带的构造演化过程,并在此过程中统计了各地层的缩短量和缩短率。通过对马家滩构造区带反演模拟的综合分析,对其形成演化机制取得以下几点认识:(1)马家滩构造区带的北部和南部属于不同类型的构造样式及成因类型,北部主要受到贺兰—银川构造系的影响和控制而形成变形并不剧烈的断裂褶皱构造,可能为逆冲推覆构造的雏形;南部主要受到六盘构造系的影响和控制,形成明显的逆冲推覆构造。(2)马家滩构造区带的石炭系—二叠系存在大型滑脱面,构造变形主要发生于滑脱面以上地层中,下部地层在滑脱过程中变形程度很小。(3)印支运动对马家滩构造区带的影响不是很强烈,主要表现为轻微的褶皱作用为主,并伴随有先存古老断裂的微弱活动。(4)马家滩构造区带的现今构造样式主要形成于燕山期—喜马拉雅期,燕山期中后期奠定大体构造格局,喜山期使之进一步发展,构造变形的主幕开始于侏罗纪末。
[Abstract]:The Majiatan tectonic belt is located between Helan-Yinchuan extensional tectonic system, Liupanshan thrust tectonic system and Ordos massif, and is located in a very special tectonic position. The formation and evolution of Majiatan tectonic zone is the result of interaction with the surrounding tectonic units. The study of the formation and evolution mechanism of the Majiatan tectonic zone has important regional tectonic significance. Many achievements and understandings have been made in the Majiatan structural zone. The thrust nappe structure style above the large slip surface has been recognized by most scholars, but the mechanism of its formation and evolution is still unclear and needs further study. In order to understand the mechanism of formation and evolution of the Majiatan structural belt, the main unconformities since the Indosinian period in the Majiatan tectonic zone and its adjacent areas were analyzed, and the results of previous studies in low-temperature thermal chronology and sedimentology were combined. The occurrence time of the main tectonic deformation in the Majiatan structural zone and adjacent area is limited. Then, four seismic sections passing through the Majiatan structural zone are simulated with time-depth conversion, denudation recovery and balanced section inversion, and the tectonic evolution process of the Majiatan structural zone is analyzed. In the process, the shortening and shortening rate of each layer are counted. Based on the comprehensive analysis of the inversion simulation of the Majiatan tectonic zone, the formation and evolution mechanism of the Majiatan tectonic zone is analyzed. The following points are obtained: the northern and southern parts of the Majiatan tectonic zone belong to different types of structural styles and genetic types. The northern part was mainly influenced and controlled by the Helan-Yinchuan tectonic system and formed a fault-fold structure which was not severely deformed, which may be the embryonic form of the thrust-nappe structure, while the southern part was mainly influenced and controlled by the six-plate tectonic system. The Carboniferous to Permian system in the Majiatan structural zone has a large detachment surface, and the structural deformation mainly occurs in the strata above the slip surface. The influence of the Indosinian movement on the Majiatan tectonic zone is not very strong, but mainly shows the slight fold action. The present tectonic style of the Majiatan tectonic zone was mainly formed in the Yanshanian and Himalayan periods, and the general tectonic framework was laid down in the middle and late Yanshanian period, which was further developed during the Himalayan period. The main curtain of tectonic deformation began at the end of Jurassic.
【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13
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本文编号：2014657