黄土物理性质与湿陷性的关系及其工程意义   总被引：1，自引：0，他引：1  

李萍  李同录 《工程地质学报》2007,15(4):506-512

以陇东地区黄土为研究对象,探讨了湿陷系数与各种物理指标的内在联系,采用多因素回归分析建立了湿陷系数与含水量、孔隙比、塑性指数(粘粒含量)的分析模型,结果显示湿陷系数与物理指标间具有良好的相关性,采用物理指标计算的湿陷总量与实验测试总量较为接近,计算结果更好的反映湿陷性随取样深度变化的规律,对评价湿陷性黄土地基具有工程实用价值。  相似文献   

准噶尔盆地成藏动力学系统划分   总被引：4，自引：0，他引：4       下载免费PDF全文

吴孔友 查明王绪龙  吴时国张立刚 聂政荣 《地质论评》2007,53(1):75-82

本文在对成藏动力学系统的概念重新描述的基础上,选择经历了多旋回构造与沉积演化的准噶尔盆地进行成藏动力学系统划分。准噶尔盆地发育6套烃源岩、多套储集层、2套区域性盖层和数个局部盖层,它们构成6套生、储、盖组合。同时,钻井揭示盆地超压发育,结合测井与地震资料,将地层压力在垂向上划分为2个常压系统和3个超压系统。该盆地垂向通道众多,构造活动期流体上下连通性好,整体可划为一个复杂的成藏动力学系统。然而,断裂活动具幕式特征,相对盆地演化史,大部分时期处于静止封闭状态。因此,进一步将准噶尔盆地划分为6个成藏动力学子系统:①二叠系自源超压半封闭型成藏动力学子系统;②三叠系他源超压半封闭型成藏动力学子系统;③侏罗系混源超压半封闭型成藏动力学子系统;④白垩系—侏罗系混源常压开放型成藏动力学子系统;⑤古近系—白垩系混源超压封闭型成藏动力学子系统;⑥新近系他源常压开放型成藏动力学子系统。不同的子系统,成藏条件、成藏动力和成藏规律不同。  相似文献   

海岸缓冲区规划管理与立法初探——以莱州湾东岸为例     

杜国云  孙祝友  刘俊菊 《地质灾害与环境保护》2007,18(3):80-85

海岸带以陆海相互作用为基本特征,并形成了一系列相关的海岸带地质灾害.海岸及近海区域是海岸带陆海相互作用的关键地区,与人类活动关系密切,减轻海岸带灾害损失和保护海岸带环境的重点应在此设立海岸缓冲区.本文在分析莱州湾东岸海岸带陆海相互作用相关的地质灾害基础上,总结提出了海岸缓冲区规划的地质地貌标志、咸-淡水过渡带标志.对缓冲区规划原则、动态管理及海岸带立法做了初步的分析与探讨.  相似文献   

冀东土壤地球化学基准值特征及研究意义   总被引：9，自引：0，他引：9  

郭海全马忠社  郝俊杰郜洪强 王三民 《岩矿测试》2007,26(4):281-286

通过系统的土壤深层（第Ⅰ环境）取样调查，研究并给出了冀东土壤中元素系列地球化学基准值及其基本特征，包括全区及不同景观区、不同流域、不同类型土壤中元素的地球化学基准值，为区域经济发展规划和资源与环境评价提供了实用的基础地球化学信息。  相似文献   

Mn content of reservoir calcite cement: A novel inorganic geotracer of secondary petroleum migration in the tectonically complex Junggar Basin (NW China)   总被引：1，自引：0，他引：1  

Cao Jian  Hu WenXuan  Yao SuPing  Zhang YiJie  Wang XuLong  Zhang YueQian  Tang Yong  Shi XinPu 《中国科学D辑(英文版)》2007,50(12):1796-1809

Electronic probe microanalysis(EPMA) results of reservoir calcite cement from fourteen core samples in the Junggar Basin show that Mn-content varies largely between different samples from below the detect limitation to 4.14%,while it displays a generally good correlation with oil-gas shows.This,therefore,likely indicates that concentration of the Mn-content of the calcite cement has a close rela-tion to the intensity of petroleum fluid charging during hydrocarbon secondary migration.In order to assess this hypothesis,oxygen and strontium isotopic measurements on sixteen calcite veins host in source sequences were carried out to investigate the feature of the oil-source petroleum fluid.Analytical results imply that during hydrocarbon generation and migration,deep hot fluid has dissolved volcanic minerals interlined between mudstone source rocks.As Mn is a kind of typical trace element enriched in volcanic rocks,it is reasonable to conclude that the petroleum fluid formed in the source sequences would be Mn-rich.Consequently,calcite cements precipitated from such Mn-rich petroleum fluid would be Mn-rich accordingly.Due to the geologic chromatographic effect during migration along reservoir rocks,the decreasing of the Mn-content of the reservoir calcite cements indicates the migration direction.Then,this novel geotracer was further successfully applied in the study of hydrocarbon migration in the Junggar Basin in combination with organic geochemical analyses during the hydrocarbon migration.The Mn content of the reservoir calcite cement appears promising as a novel inorganic geotracer for the petroleum migration.This paper represents a search for novel indicators of secondary petroleum migration in tectonically complex basins based on fundamentals of the reservoir fluid-rock interactions.  相似文献   

Bacterial and organic matter distribution in the sediments of the Thracian Sea (NE Aegean Sea)     

Paraskevi N. Polymenakou  Glykeria Fragkioudaki  Anastasios Tselepides 《Continental Shelf Research》2007

Recently, black carbon has been introduced as the form of carbon that may be separated from the biologically mediated carbon cycle thereby representing the non-bioavailable fraction of the estimated organic carbon. It has been speculated that the bioavailability of organic matter may be a limiting factor for the presence of active bacteria within the sediments. In order to address this question, marine sediments were collected from the Thracian Sea (Eastern Mediterranean), a complex system impacted by riverine inputs and Black Sea water masses. In addition to counts of total bacteria, we estimated the fraction of active bacteria by using a destaining step to the DAPI staining method. Black carbon was also estimated following the thermal oxidation method in order to determine the fraction of the refractory organic matter. The fraction of black carbon to total organic carbon varied from 16% to 53% indicating that black carbon constitutes a significant pool of sedimentary organic carbon in the Thracian sea. A fraction ranging from 18% to 97% was scored as nucleoid containing cells. We did not record any significant differences in the fraction of nucleoid-containing bacteria among sediment depths (P<0.05) indicating that there was no accumulation of dead bacterial cells with depth. The same was observed for the fraction of black carbon and bioavailable organic carbon with sediment depth (P<0.05) indicating that benthic consumers are not the key regulators of the organic matter pool in these sediments but have a minor effect. A possible reason for these observations and for the uncoupling between the active bacterial fraction and the bioavailability of organic matter could be (i) the presence of refractory components in the estimated bioavailable organic matter and (ii) the hydrological and geological complexity of the study area. The North Aegean marginal slopes are highly unstable experiencing frequent seismic events. These events are capable of inducing sediment transport from the upper slopes thus altering the entire sediment profile. On the other hand, the significant correlations that were recorded between nucleoid-containing cells and phytopigments (chlorophyll a, phaeopigments, chloroplastic pigment equivalents) at all sediment depths indicate that bacterial communities respond immediately to the deposited phytodetritus, using it as a primary source of carbon and energy. Our data suggests that the Thracian Sea sediments are by no means homogeneous and can best be described as a mosaic controlled by numerous local and regional environmental factors.  相似文献   

青藏高原东缘龙门山晚新生代走滑挤压作用的沉积响应   总被引：33，自引：0，他引：33  

李勇  周荣军  Densmore A L  Ellis M A  黎兵 《沉积学报》2006,24(2):153-164

成都盆地位于青藏高原东缘，夹于龙门山与龙泉山之间，盆地的长轴方向平行于龙门山，呈现为北东—南西向展布的线性盆地。盆地中充填了3.6Ma以来的半固结—松散堆积物，最大厚度为541 m，在垂向上由下部的大邑砾岩、中部的雅安砾石层和上部的上更新统至全新统砾石层组成，其与下覆地层均为不整合接触，显示该盆地是一个单独的成盆期,并非是在中生代前陆盆地基础上形成的继承性盆地。在垂直于龙门山造山带方向上，成都盆地具不对称的楔形结构,沉积基底面整体向西呈阶梯状倾斜，盆地中充填的碎屑物质均来源于盆地西侧的龙门山，具横向水系和单向充填的特征；而且盆地的沉降中心具有逐渐向远离造山带方向迁移的特征，显示盆地的挤压方向垂直于龙门山主断裂，造成了成都盆地在垂直于造山带方向上的构造缩短。在平行于龙门山造山带方向上，成都盆地具有一系列的北东向延伸的次级凸起和凹陷，凹陷和凸起相间分布，且在空间上呈斜列形式展布于盆地的底部，其中次级凹陷（沉降中心）和冲积扇具有向平行龙门山造山带方向迁移的特征，表明成都盆地西缘的龙门山断裂具有右旋走滑的特征。鉴于以上特征，认为成都盆地是在龙门山造山带晚新生代走滑与逆冲的联合作用下形成的走滑挤压盆地。  相似文献   

四川盆地东部海相下—中三叠统界线的锶同位素年龄标定   总被引：5，自引：0，他引：5  

黄思静  裴昌蓉  卿海若  胡作维  吴素娟  孙治雷 《地质学报》2006,80(11):1691-1698

中国西南地区海相下—中三叠统以火山碎屑岩为其直观界线,该年龄的标定可为区域地层年表和国际地层委员会全球标准年表研究提供重要的下—中三叠统界线年龄参考值.基于此,本文测试了四川盆地东部华蓥山下—中三叠统界线火山碎屑岩附近的石膏和硬石膏样品87Sr/86Sr比值,以及相应的Si、Ca、Mg、Mn、Sr以及SO42-的含量,根据锶同位素地层学的原理,尝试对下—中三叠统界线进行了年龄标定;同时评估了样品的成岩蚀变性、对海水信息的代表性以及年龄标定结果的可靠性.火山碎屑岩附近5个样品的87Sr/86Sr比值变化在0.708243~0.708391之间,标定的年龄值在240.5~242.5Ma的范围内,2个紧靠火山碎屑岩样品的年龄值在242Ma左右(分别为241.9Ma和242.5Ma),从而为华南地区以火山碎屑岩作为海相下—中三叠统界线的合理性提供了重要的化学地层学依据,也为全球下—中三叠统界线提供了一个新的年龄值.  相似文献   

准噶尔盆地西北缘油气成藏演化的包裹体地球化学研究   总被引：7，自引：2，他引：7  

曹剑胡文瑄  姚素平张义杰王绪龙  张越迁唐勇 《地质论评》2006,52(5):700-707

准噶尔盆地西北缘地区是叠合盆地“多源多期”油气成藏的一个典型实例。本文通过对油气运聚过程中的“化石”记录——包裹体进行研究，采用储层游离烃和包裹体烃成分对比分析，有机包裹体光性特征鉴别，流体包裹体均一温度结合地层埋藏-热史，以及有机包裹体红外光谱特征分析，确定了油气来源与成藏期次。再结合烃源岩生排烃史和构造发育史，恢复了复杂的油气成藏演化过程：①中晚二叠世，下二叠统佳木河组烃源油沿断裂和输导层运移至石炭系-二叠系圈闭中聚集；②晚三叠世到早侏罗世，下二叠统风城组烃源油沿断裂、不整合和输导层运移，在二叠系-三叠系的各套储层中聚集；⑧早白垩世至今，佳木河组的天然气，以及中二叠统下乌尔禾组烃源油推动早期的原生油藏向上倾方向运聚。  相似文献   

Emplacement of Proterozoic massif-type anorthosite during regional shortening: evidence from the Bolangir anorthosite complex (Eastern Ghats Province, India)   总被引：2，自引：0，他引：2  

Christoph Dobmeier 《International Journal of Earth Sciences》2006,95(4):543-555

A study of the 933±32-Ma-old Bolangir massif-type anorthosite complex (Eastern Ghats Province, India) yielded strong evidence for anorthosite emplacement during regional shortening, and thereby new insights in massif-type anorthosite formation. Several lines of evidence strongly suggest synchronism of plutonism and regional deformation. First, structures in the country rocks, which imply N–S-directed shortening accompanied by E–W extension, are mirrored by a E–W trending post-magmatic foliation and N–S trending shear zones in the anorthosite complex. Near the intrusion, the foliation in the country rocks becomes parallel to the contact and an internal marginal foliation, and foliation triple points occur in the country rocks. Second, synshortening dikes inside and outside the anorthosite complex are filled with pluton-related melts. Third, ferrodiorites, which are considered late-stage differentiates of the anorthositic pluton, concentrate in tectonic voids at the pluton margin. Some of these occurrences have been affected by the last increments of the regional deformation, but others transect the same structures. Ascent mechanism and significance of the adjacent terrane boundary of the Eastern Ghats Belt for ascent and emplacement of the Bolangir anorthosite complex are discussed. The results of this study imply that emplacement of Proterozoic massif-type anorthosite is not restricted to extensional settings.  相似文献