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871.
国内外油气勘探实践表明,含盐盆地的油气富集和分布与盆地内沉积的盐岩密切相关。东濮凹陷是我国东部地区典型的含盐油气富集盆地,作者通过深入研究其地层层序特征及盐岩纵横向分布特点,进一步剖析了盐岩沉积的主要控制因素及其与生储盖层的关系,搞清了含盐盆地油气的分布和富集与盐岩的关系,指出无论在垂向上还是横向上,东濮凹陷盐岩一般都与暗色烃源岩共生,而且盐岩与同期沉积的砂岩表现为长消关系。研究认为盐岩可作为油气上盖或侧向遮挡,与源岩、储集层可组成良好的生储盖配置关系,利于油气富集区带的形成,对构造和隐蔽油气藏的形成都发挥了积极的作用,并指出与盐岩有关的文东北部和胡状集地区是下一步挖潜的有利勘探方向。研究成果也可为国内外同类含盐盆地的油气勘探提供一定的借鉴经验。 相似文献
872.
The enigma of the origin and development of plains-type folds, as they were christened in the early 20th Century, essentially has been solved. The folds, a considerable distance from the tectonic disturbance, were formed by draping of sediments over differentially displaced Precambrian basement fault blocks. These Precambrian basement fault blocks controlled the location, size, and shape of the folds. Forces were transmitted through the rigid basement causing readjustment along the indigenous fracture/fault pattern formed much earlier. In the U.S. Midcontinent, the crystalline basement is overlain by a thin veneer of sediments, and once the structures were formed, they continued to develop as evidenced by features in the overlying sediments. As the stress was transmitted through the basement and then relaxed, the fault blocks moved differentially in concert to these outside forces. Sediment compaction and nondeposition over structural topographic highs reacted accordingly to form the features as seen today. To determine the structural history, structural closure on different horizons on the anticline is plotted in their appropriate stratigraphic position at depth. This gives a compaction line for each tectonically coherent segment. Similar segments show a relatively straightline with offsets at major unconformities indicating breaks in the continuum. It is at these breaks that the section can be stretched until the compaction line matches as a continuum with the resulting gap giving the approximate amount of missing section for that part of the rock column. Conversely, the amount of closure on a structure at depth for each line segment can be estimated by extrapolating downward in that segment. This technique to determine depth of burial and thus the amount of missing stratigraphic section from well data at numerous locations has been compared with estimates made by other methods and the results are similar. Where no other data are available or for quick estimates, then, it is proposed that this approach will give reasonable results and that the values can be used as a constraint in basin modeling. 相似文献
873.
冀中坳陷古近纪的伸展构造 总被引:15,自引:0,他引:15
冀中坳陷的构造格架是新生代的伸展构造系统。该系统以大兴、保定-石家庄拆离滑脱断层为主体,与牛东-河东、马西、宁晋、新河等伸展断层以及徐水-安新变换带和衡水、宝坻-桐柏镇变换断层等组合而成。据平衡剖面和基底沉降曲线分析,冀中坳陷古近纪伸展作用过程持续发育,具幕式特点,以沙三期伸展作用最为强烈。地壳的快速伸展作用与火山活动强度之间缺乏耦合关系。冀中坳陷的动力学成因与伸展背景下的剪切作用有关。 相似文献
874.
"96.1"高原暴雪过程三维条件性对称不稳定的数值研究 总被引:37,自引:22,他引:15
利用“96.1”青藏高原东北部暴雪过程的较成功的中尺度模拟的输出资料,用非纬向非平行基流中的对称不稳定模式,对“96.1”暴雪发生发展过程的动力学机制进行了三维基流中二维非线性对称不稳定数值模拟试验。结果表明,ψ场和ω场的三维配置与切变线的演变过程相当一致,说明用三维基流中二维非线性对称不稳定可能能较好地描述SI在切变线东伸南移过程中所起的作用。 相似文献
875.
论中国东部大型盆地区及邻区地质-地球物理复合尺度解析 总被引:7,自引:3,他引:4
作为对中国东部陆缘地带大型盆地区及邻区地质-地球物理综合研究的部分结果,本文的基本认识:(1)穿过松辽盆地的1孙吴-双辽断裂可能是东倾伯低角度壳内断裂;(2)松辽盆地和渤海湾盆地可能属于“混合型裂谷盆地”;(3)东海盆地台北坳陷处在多期次张性应力场环境中,使在其西部附近产生张性正断层系;(4)欧亚大陆东部新生代区域构造运动总体处于右旋走滑拉张环境,其动力因素包括板块运动和地幔物质运动;(5)研究区莫霍面具有较为复杂的变化;(6)复合尺度研究方法是地质-地球物理综合分析的必要手段。 相似文献
876.
877.
沙区绿洲人地系统演进探讨——以民勤盆地为例 总被引:4,自引:0,他引:4
资源与环境问题已成为当代人类生存与发展的重大问题,它通过人地系统中人与地之间的相互联系,以各种方式和强度作用于人类。人地系统有其运行规律和演进机制,要建立协调的人地关系、促进沙区绿洲的可持续发展,就必须清楚地了解其人的地系统的动态演进机制。通过分析民勤盆地人地系统的演进过程,提出了人地系统演进的机制和驱动力,从而为更好地调控沙区绿洲人地系统的演进提供依据。 相似文献
878.
879.
塔里木盆地北部隆起牙哈断裂带负反转过程与油气聚集 总被引:19,自引:0,他引:19
采用地层厚度分析、“零点”分析、位移 /距离曲线分析和断层生长指数分析等方法,讨论了牙哈负反转断裂带的几何学和运动学特征、主反转期及控油作用,结果表明牙哈主断裂主反转期为早白垩世,负反转活动结束于中新世康村期-上新世库车期。牙 1号断裂主反转期为中新世苏维依期,牙 2号断裂主反转期为晚白垩世-老第三纪,二者都于中新世康村期结束反转活动。牙哈断裂带油气聚集和分布与断裂的负反转活动有关。 相似文献
880.
The SHETRAN physically based, spatially distributed model is used to investigate the scaling relationship linking specific sediment yield to river basin area, for two contrasting topographies of upland and more homogeneous terrain and as a function of sediment source, land use and rainfall distribution. Modelling enables the effects of the controls to be examined on a systematic basis, while avoiding the difficulties associated with the use of field data (which include limited data, lack of measurements for nested basins and inability to isolate the effects of individual controls). Conventionally sediment yield is held to decrease as basin area increases, as the river network becomes more remote from the headwater sediment sources (an inverse relationship). However, recent studies have reported the opposite variation, depending on the river basin characteristics. The simulation results are consistent with these studies. If the sediment is supplied solely from hillslope erosion (no channel bank erosion) then, with uniform land use, sediment yield either decreases or is constant as area increases. The downstream decrease is accentuated if rainfall (and thence erosion) is higher in the headwaters than at lower elevations. Introducing a non‐uniform land use (e.g. forest at higher elevations, wheat at lower elevations) can reverse the trend, so that sediment yield increases downstream. If the sediment is supplied solely from bank erosion (no hillslope erosion), the sediment yield increases downstream for all conditions. The sediment yield/basin area relationship can thus be inverse or direct, depending on basin characteristics. There still remains, therefore, considerable scope for defining a universal scaling law for sediment yield. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献