松辽盆地嫩江组泥页岩有机质富集模式探讨——以嫩江组一、二段油页岩为例     

商斐  周海燕  刘勇  周学先  王岚  毕赫  王国昌  宋力  陈睿倩 《中国地质》2020,47(1):236-248

通过理论模型推演与地质研究实例相结合的方式,以松辽盆地白垩系嫩江组一、二段发育的富有机质页岩(油页岩)为例,重点利用松科1井(南孔)嫩江组取芯井已有测试分析资料,综合有机碳(TOC)含量、黄铁矿硫同位素、全岩元素,以及相关测井、地震资料,综合探讨分析了嫩江组油页岩的成因机制以及油气勘探意义。研究认为:(1)将松辽盆地嫩江组油页岩的形成机制完全归因于海水侵入湖盆很可能是不全面的。虽然海侵能够导致湖盆水体咸化以及藻类勃发,但由于海侵时富氧表层海水对湖盆底部氧化还原环境的改变,"海侵"发生时可能在一定程度上抑制有机质在沉积物中的富集保存,这一点可以从松科1井连续地化剖面上得到验证;(2)海侵对富有机质页岩沉积的促进因素很可能主要体现在海侵结束后湖盆的持续咸化带来的藻类勃发;(3)嫩江组泥岩内存在全盆地广泛分布的火山凝灰岩沉积,且通常与油页岩呈共生关系。古松辽湖盆生产力的提升与火山灰输入所带来的营养物质,如磷、铁等直接相关;(4)嫩江组一、二段油页岩的形成可能是海侵结束后湖盆水体咸化与火山灰瞬间大量输入所诱发的湖盆水体富营养化事件多因素共同作用的结果。油页岩含油率分布规律显示在湖盆生产力普遍较高的情况下,沉积区水体深度越深、越远离河流碎屑输入,则有机质的富集保存条件越好,油页岩品质越高。  相似文献   

黔南地区~3 km油气深孔地应力测量与构造应力场分析     

曹慧  孙东生  苑坤  李阿伟  张光晗 《中国地质》2020,47(1):88-98

地应力大小和方向信息是非常规油气勘探开发及区域构造应力场特征分析的重要基础数据。为了解黔南紫云地区的现今地应力状态,采用基于钻孔岩心的非弹性应变恢复(ASR)地应力测量方法,获取了紫云地区2877～2985 m石炭系打屋坝组地层的地应力信息,分析了区域构造应力场特征,探讨了油气保存条件。结果表明:(1)黔南紫云地区近3 km处石炭纪地层现今地应力状态表现为以垂向应力为主的应力环境,测点处最大水平主应力方向近SN向。(2)紫云地区近3 km处岩心实测最大水平主应力方向与燕山早期古构造应力场最大主应力方向大致相同,一定程度上反映了燕山末期—喜马拉雅运动对次生油气藏的改造程度较小,有利于黔南坳陷内部油气藏的保存。  相似文献   

Reservoir Potential of Silurian Carbonate Mud Mounds in the Southern Sichuan Basin, Central China     

ZHAO Wenzhi YANG Xiaoping Steve KERSHAW ZHANG Baomin 《《地质学报》英文版》2006,80(5):684-692

Lower Silurian mud mounds of the Shinuilan Formation, located in the southern Sichuan Basin, China, have developed in open shelf settings in deeper water than shallow-water reef-bearing limestones that occur in the region. An integration of the outcrop, drill data and seismic profiles show that contemporaneous faults have controlled the boundary and distribution of the sedimentary facies of Lower Silurian rocks in the southern Sichuan Basin. Mounds appear to have developed in the topographic lows formed by synsedimentary faulting, on the sheff of the Yangtze Platform. Average mound thickness is 20 m, maximum 35 m. Mounds are composed mainly of micrite, possibly microbially bound, and are overlain by shales. Mound tops are preferentially dolomitized, with the Mg^2＋ source probably from the clay content of the mound-top carbonate. Microfacies analysis and reconstruction of the diagenetic history reveal that the mound tops have higher porosity, and are gas targets; in contrast, mound cores and limbs show pores filled by three generations of calcite cement, and therefore have a low gas potential.  相似文献   

中国油页岩富集与地质事件研究     

柳蓉  张坤  刘招君  闫旭  于佳琦 《沉积学报》2021,39(1):10-28

油页岩是一种有机质富集的细粒沉积岩,高古湖泊生产力和稳定的还原环境是油页岩成矿的关键.越来越多的学者研究发现,在含油页岩沉积组合序列中,经常出现火山、热液、大洋缺氧、气候突变、海侵、重力流等地质事件.通过对全国50个盆地、95个含矿区油页岩成因和分布规律的总结和归纳,揭示出火山、热液、大洋缺氧、气候突变、海侵、重力流等...  相似文献   

四川盆地长宁地区海相页岩吸附气含量演化特征 ——以N201井五峰组—龙马溪组一段为例     

聂舟  衡德  邹源红  肖红纱  陈义才  康宇  彭文秋 《海相油气地质》2021,26(1):43-50

吸附气是页岩气的重要赋存形式和组成部分.为了明确四川盆地长宁地区五峰组—龙马溪组一段页岩在埋藏过程中吸附气含量的演化规律,利用页岩等温吸附实验、钻井现场解吸和测井综合解释资料,建立了页岩吸附气含量与地层温度、地层压力、页岩TOC等主要影响参数的多元回归数学公式,结合典型评价井(N201井)的埋藏史、热史,对不同地质时期...  相似文献   

积石山Ms6.2级地震区大沙沟泥土流灾害链成因分析     

刘传正  梁宽  王秀英 《地质论评》2024,70(3):960-974

2023年12月18日23时59分,甘肃省积石山县发生Ms6.2级地震,最大地面加速度达到1.0 g。距震中20 km的青海省民和县中川乡大沙沟上游台地出现约15×104 m2液化陷落,活动水土体积约60×104m3,约45×104m3侧流进入沟道,自北向南顺沟冲击形成灾害链,在草滩—金田村堆积约30×104 m3,造成20人遇难。笔者等采用现场调查访问、卫星遥感和无人机图像解译、含水量测定、分析描述和量化计算等方法,对泥土流灾害链的形成因素、动力学机理和运动特征等进行了研究。大沙沟泥土流灾害链分布长度约3. 1 km,可以划分为土体液化流失区、泥土流壅堵回淤区、路基堵溃冲击区、泥土堆积压埋区和泥水漫流区五部分,从上游到下游依次造成耕地损毁、电塔倒塌、灌渠破坏、摧毁村路、埋压乡道、压埋人员房屋和淤埋黄河引水灌渠等。泥土流具有过渡性三元分层结构,包括底部的冰水层、中间泥流层和上部的湿土层。液化土体从启动进入沟道到金田村被埋压的运动时间不足10 min,泥土流启动到美一村路基堵溃的时间约为4. 38 min,到达到草滩村牌坊的时间约为6. 15 min,在随后的3. 50 min内酿成了草滩—金田村灾难。泥土流灾害链的形成是地质、水源、动力、地形和承灾体等诸多因素遭遇叠加的结果,包括厚层粉砂土、高位地下水、强烈的地震动、平缓地形倾向沟谷出口、路基阻挡蓄能溃决和沿途遭遇多处承灾体等要素。泥土流在平缓沟道实现远程运动的动力学效应包括启动区土体液化、入沟“闸门”束流、跨沟路基堵溃、沟道冰水润滑、水土“列车”接续入村堆积和灾民地震应激惊恐等多种效应的接续传递、叠加耦合。农村社区建于大沙沟冲积滩地上,无形中增大了成灾风险和自主防范的难度。笔者等提出的防范对策包括开展防灾减灾培训、农田灌溉改为渗灌滴灌、民居选址建设避开河沟洪泛冲积滩地、疏浚河道拓宽过流断面和上游开展水土保持等。  相似文献   

海岸滩涂围垦的适宜速度研究--以江苏淤泥质海岸为例   总被引：2，自引：0，他引：2  

王艳红  温永宁  王建  张忍顺 《海洋通报》2006,25(2):15-20

滩涂围垦是基础设施建设占用大量耕地情况下江苏省实现耕地总量动态平衡的主要途径之一,随着社会经济的发展和对土地需求量的不断增加,滩涂围垦与海岸带环境保护之间的矛盾日渐突出。但以实现耕地总量动态平衡为目的的滩涂围垦需要以滩涂总量动态平衡为前提才能保证滩涂资源的可持续利用。通过对江苏海岸的发育和围垦历史以及淤蚀动态的分析,提出以滩涂总量动态平衡为前提的滩涂围垦适宜速度,并对江苏海岸不同岸段的适宜围垦速度进行计算分析,提出围垦活动的强度应当同时综合考虑围垦后的经济和社会效益与拟围滩涂所在岸段的自然淤蚀状况(即滩涂的承载力),以实现同时满足围垦活动与滩涂资源保护的平衡。  相似文献   

长江口北槽浮泥周期性变化初探   总被引：4，自引：3，他引：1  

蒋国俊  姚炎明 《海洋学报》2006,28(2):135-139

根据2000年长江口北槽浮泥的实测资料,分析浮泥厚度和体积等几何尺度随时间的变化,发现长江口北槽浮泥存在日、半月和年际三种周期变化;日周期的变化受潮流动力周期的控制,这是由潮流冲刷浮泥形成的悬沙并再絮凝沉积造成的;半月周期的变化受潮流半月周期变化引起的泥沙供给量的变化控制;年周期的变化主要是由影响细颗粒泥沙絮凝沉积的长江口水温的年度变化所控制,泥沙供给和动力的年周期变化也有一定的影响.  相似文献   

The structure of soft-bottom benthic communities in the vicinity of the Texas Flower Garden Banks,Gulf of Mexico     

Josephine Y. Yingst  Donald C. Rhoads 《Estuarine, Coastal and Shelf Science》1985,20(5):569-592

Biological and sedimentological samples were obtained in June 1980 from box cores taken in 100–200 m of water on sandy-mud sediments near the East and West Flower Garden Bank reefs, on the Texas-Louisiana Continental Shelf. The objective was to obtain baseline information about sedimentary parameters and organisms adjacent to the FGB environments in order to allow inferences to be made about potential effects of physical disturbance of the seafloor on the resident benthos.Most infaunal organisms are found in the upper 3–5 cm of the bottom. Permanent meiofauna dominate in both numbers and biomass. X-radiographs of sediment fabrics show all stations to be reworked by head-down deposit-feeders or errant bioturbators. Taxa responsible for this bioturbation were not quantitatively sampled.Macrofaunal densities range from 3000 to 25000 m^?2 and total meiofauna from 221 to 892 × (10 cm)^?2. Nematodes dominate followed in equal abundance by foraminiferans, polychaetes, and copepods. Seventy-five percent of the total sediment ATP in the top 3 cm is contributed by meiofauna. These benthic assemblages are hypothesized to represent a mixture of pioneering and high-order successional stages.Bacterial abundances are positively correlated with organic content and inversely correlated with macro- and meiofaunal densities. This inverse relationship may reflect consumer cropping intensities. Both microbial ATP and bacterial biomass are lower than reported for the Georgia Bight Shelf, Cape Blanc, West African Shelf, western coast of Norway, and Long Island Sound. Bacterial counts are lower than those recorded for the East China Sea and the Amazon River shelf. Moderate to low standing stocks of benthos, dominated by meiofaunal-sized taxa, further suggest that this area of the Gulf of Mexico is a relatively oligotrophic system for infaunal benthic consumers.Higher order successional stages are, in general, adversely affected to a greater extent than pioneering stages by physical disturbance. In the Texas-Louisiana shelf region, dilution of an already food limited system by inert barium sulphate would be expected to result in even lower standing stocks of benthic infaunal invertebrates.  相似文献   

Mud diapirism within Indus fan sediments: Murray Ridge, Gulf of Oman     

J. S. Collier  R. S. White 《Geophysical Journal International》1990,101(2):345-353

  相似文献