敦煌盆地侏罗纪原型盆地分析

发布时间：2018-04-21 05:06

本文选题：原型盆地 + 边缘相　；参考：《中国海洋大学》2015年硕士论文

【摘要】：敦煌盆地位于甘肃、新疆与青海的交界处,勘探程度低,制约着盆地内油气资源的勘探开发。本论文根据原型盆地分析的基本原则,基于敦煌盆地野外地质观察、航磁异常分析及前人对敦煌盆地及周缘盆地基底特征的研究,厘定民丰-且末断裂为敦煌盆地的西部边界、红柳沟-拉配泉断裂为敦煌盆地的西南边界、阿尔金断裂为敦煌盆地的南部和东部边界。基于侏罗纪中国大地构造特征结合前人的深地震资料解释,研究表明敦煌盆地形成演化不仪受大陆边缘板块构造运动远程效应的影响,又受已形成中国大陆构造的影响,还受盆地基底与活动带和地块之间的大地构造位置影响。根据对盆地内二维地震资料解释,盆地以三危山为界,为南北两个单断箕状凹陷。根据盆地内古气候、古生物、沉积相、沉积物颜色、湖盆面积、构造运动和区域应力场变化的差异,可以将侏罗系划分为中下侏罗统和上侏罗统两个构造层。结合盆地露头剖面边缘相和物源分析,指出三危山断裂为控凹边界、阿尔金断裂为控盆边界。根据地震时深换算,绘制出盆地的残留地层分布,下侏罗统在各凹陷内均有分布,厚度较小,各凹陷残留地层孤立分布,残留地层厚度受断裂影响明显；中侏罗统沉积范围加大,残留地层厚度大,此时五墩凹陷受三危山断裂控制是敦煌盆地的沉降、沉积中心,且五墩凹陷与湾窑凹陷连通,三危山以南的红柳沟凹陷与大坝凹陷未连通,其中红柳沟凹陷内的残留地层受阿尔金断裂控制明显；晚侏罗世,敦煌盆地进入消亡阶段,只有五墩凹陷、红柳沟凹陷和大坝凹陷有地层分布,各凹陷连通性差,但五墩凹陷一直是盆地的沉积、沉降中心。
[Abstract]:The Dunhuang basin is located at the junction of Gansu, Xinjiang and Qinghai, and its exploration degree is low, which restricts the exploration and development of oil and gas resources in the basin. Based on the basic principles of prototype basin analysis, field geological observation of Dunhuang basin, aeromagnetic anomaly analysis and previous studies on basement characteristics of Dunhuang basin and its peripheral basins, the Minfeng-Qiumo fault is defined as the western boundary of Dunhuang basin. Hongliugou-Lapiquan fault is the southwestern boundary of Dunhuang basin and Altun fault is the southern and eastern boundary of Dunhuang basin. Based on Jurassic geotectonic characteristics of China combined with the interpretation of previous deep seismic data, it is shown that the formation and evolution of Dunhuang basin is not influenced by the remote effect of tectonic movement of continental margin, but also by the formation of continental tectonics in China. It is also affected by the tectonic position between the basement of the basin and the active belt and block. According to the interpretation of the two dimensional seismic data in the basin, the basin is bounded by Sanwei Mountain, which is composed of two single-fault dustpan sag in the north and south. According to the differences of paleoclimate, paleontology, sedimentary facies, sediment color, lake basin area, tectonic movement and regional stress field, the Jurassic can be divided into middle and lower Jurassic and upper Jurassic tectonic layers. Based on the analysis of the marginal facies and provenance of the outcrop section of the basin, it is pointed out that the Sanwei Mountain fault is the boundary of the controlled concave and the Altun fault is the boundary of the control basin. According to the seismic time depth conversion, the residual stratigraphic distribution of the basin is plotted. The lower Jurassic is distributed in each sag, the thickness is relatively small, the residual strata are isolated in each sag, and the thickness of the residual strata is obviously affected by the fault. The middle Jurassic sedimentary range is enlarged, and the thickness of the residual strata is large. At this time, the Wudun depression is controlled by the Sanwei Mountain fault and is the sedimentation center of the Dunhuang basin, and the Wudun sag is connected with the Wanyao sag. The Hongliugou sag south of Sanwei Mountain is not connected with the dam depression, in which the residual strata in Hongliugou sag are obviously controlled by Altun fault. There are stratigraphic distribution in Hongliugou sag and dam sag, and the connectivity of each sag is poor, but Wudun sag is always the sedimentary and subsidence center of the basin.
【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P534.52;P542

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