【作者】 梁苏娟；

【导师】 刘池阳；

【作者基本信息】 西北大学 ， 矿产普查与勘探， 2001， 硕士

【摘要】 冀中坳陷位于渤海湾盆地西北部，属于次一级构造单元，坳陷与盆地具有相同的构造演化史。晚第三纪，盆地结束了早第三纪的伸展裂陷活动，进入了坳陷盆地阶段。本文着重分析冀中坳陷晚新生代坳陷阶段的构造及油气赋存特征。坳陷在晚新生代沉积了上第三系馆陶组和明化镇组，第四系固安组、杨柳青组、欧庄组及全新统。沉积相以河流相为主，霸县凹陷和武清凹陷湖沼相较发育。包括冀中坳陷在内的河北平原在第四纪发生了六次海侵，冀中坳陷属于滨海相。坳陷及邻区，尤其北区和北缘的渤张构造带，晚新生代构造活跃。坳陷内北北东向断裂以右旋剪切活动为主。河东-牛东断裂垂向活动强烈，马西、河间断裂右旋剪切活动显著，正花状伴生构造发育；向南，断裂活动较强。断裂组合平面上以雁列、帚状、羽状为主，剖面上以花状、梳状、“y”字叠合状为主。北北东-北东向断层发生了顺时针偏转，北西向断层发生了逆时针偏转。坳陷北缘的渤张构造带北西向左旋张剪活动明显，使该带发育晚新生代雁列式断陷群。晚新生代发育呈共轭剪切关系的两个地震带，即北北东向的唐山-河间-磁县地震带与北西向的渤张地震带。沉积、断裂、地震、海侵、河道变迁等地质活动规模及特征均表明，坳陷在晚新生代应力场相对于早第三纪发生了变换，即由北西西-南东东向拉张为主伴随北北东-北东向右旋剪切，转变为北北东向右旋剪切为主。晚新生代坳陷发生的一系列构造变动，是盆地深部热冷缩作用与板块构造运动相联合的结果。板块构造运动以（古）太平洋板块向中国大陆板块俯冲方向的改变和速度的增加为主控因素；同时，受印度板块锲入欧亚板块对华北地区所产生的“滑线场效应”的远程影响。晚新生代构造活动对前上第三系成藏既有有利的一面，也有不利的一面。沉积与断裂活动联合作用，控制晚新生代油气藏的形成。烃源岩以沙三与沙一段为主，沙一段最有利。储集体为河道砂岩，断层作为油气运移的主要通道，对油气成藏有重要作用。断裂活动不甚强烈的中区南部，是上第三系油藏的主要分布区，也是目前最有利的上第三系油藏勘探区。向北，岔河集-马西-河间构造带上扭动背斜翼部，文安斜坡南段及武清凹陷等地区上第三系均具备油气成藏条件。武清凹陷中部在晚新生代沉积速度快，厚度大，湖沼相占主要地位，断裂活动较弱，具备了生物气、生物-热催化过渡带气的浅层天然气成藏条件。更多还原

【Abstract】 Jizhong depression, as one of subordinate tectonic unit of Bohaiwan basin, has the same evolution as the basin , which rifted in early Cenozoic and depressed in late Cenozoic. Late Cenozoic characteristics of tectonics and hydrocarbon accumulation of the depression are focused on in this paper. Guantao and Minghuazhen formation were developed in Neogene, Gu’an, Yangliuqing, Ouzhuang formation in Quarternary. They are featured by fluvial facies in the depression except lacustrine-bog facies in wuqing sag. Hebei Plain including the depression received six times sea transgressions in Quarternary. Tectonic movements in the depression and its neighborhoods, esp. in Bo-zhang zone, acted strongly in late Cenozoic. Faults trending NNE-NE dextrally sheared violently associated with kinds of fault assemble styles, for instance , en echelon-like, feather-like, broom-like in plane and positive-flower-like, comb-like, superimposed "Y" like etc. in profile. Bo-zhang zone striking NW, suffered strongly sinistral tensional shear movement. In late Cenozoic, violent thickness variance of Neogene sediment in the northern area, active seisms in Tangshan-Hejian-Cixian zone and Bo-zhang zone, six times invasions in Quarternary and migrantion of river channels, fault movements, etc., as the geological phenomena, all indicate active tectonic natures, which were dominated by dextral shear stress trending NNE. Tectonics in late Cenozoic Jizhong Depression was responded to by united efforts of contraction in deep Earth, and plate movements controlled by paleo-Pacific plate downgoing to Eurasion plate with direction changing and speed increasing ,and influenced by striking-line effect from strong collision between Indian Plate and Eurasian Plate in late Cenozoic. Tectonic movements in late Cenozoic had either positive or negative effect on hydrocarbon accumulation before Neogene. Deposit and fault structures controlled oil and gas accumulation in late Cenozoic, whose main source beds are Es1 and Es3 (Es1 was the most favorable ), container rock was sand of paleo-river channels and key passage was faults. Southern middle area of the depression as main Neogene hydrocarbon accumulative area, also is the most favourable prospect target. The wings of anticlines in Chaheji-Maxi-Hejian faulted zone and Wuqing sag possessed hydrocarbon accumulation conditions. In late Cenozoic, high speed and large thickness sediment, lacustrine bog facies, fairly weak fault movements in central Wuqing sag, resulted in biogenic and biogenic-thermo-catalytic gas pool with large possibility.更多还原