东北及邻区晚古生代地层接触关系与佳-蒙地块的形成和演化   总被引：1，自引：0，他引：1  

李宁  王成文 《吉林大学学报(地球科学版)》2017,(5):1331-1340

东北及邻区晚古生界及其相关地层间的接触关系含有丰富的大地构造信息,本文系统梳理了这些资料,用以阐述佳-蒙地块的形成与演化。佳-蒙地块南缘的西别河组、北缘的卧都河组及东缘的黑台组等晚志留世—早泥盆世地层底部均发育不整合(或非整合),揭示了东北地区曾经历了一次十分重要的大地构造运动,标志着佳-蒙地块的形成。区内泥盆纪—石炭纪和石炭纪—二叠纪地层之间多为整合接触,说明这一时期佳-蒙地块处于稳定沉降接受沉积阶段。佳-蒙地块南缘晚二叠世林西组底部的平行不整合界面及其上部的磨拉石建造,以及中—晚二叠世地层序列由海相向陆相的转化,表明林西组处于前陆盆地的沉积环境,标志着佳-蒙地块与华北板块发生碰撞拼合。佳-蒙地块南缘早三叠世卢家屯组底部的不整合及卢家屯组下部砾岩所具有的磨拉石建造特征,说明碰撞造山作用仍在持续进行,属于递进造山作用。晚三叠世大酱缸组底部的不整合,说明造山作用已经完成,佳-蒙地块独立发展的历程结束。  相似文献   

Dating the Tectonic Deformation since the Middle Triassic for the Tongnanba Anticline in the Northeastern Sichuan Basin and its Geological ImplicationsEI北大核心CSCD     

Chen L.  He D.  Wang B.  Li Y.  Mei Q.  Wen Z. 《大地构造与成矿学》2017,(3):433-445

Tongnanba anticline lies in the northeastern Sichuan Basin and experienced multi-stages tectonic compression and superimposition since the Middle Triassic. Its formation and evolution process are chiefly controlled by the squeezing and thrusting from the Micangshan structure belt from NW to SE and subjected to the tectonic superimposition from the Dabashan structure belt from NE to SW. Therefore, to confine the timing of Tongnanba anticline multi-stages deformation is of great effectiveness to constrain the timing of Micangshan intra-continental deformation since the Middle Triassic, and also provides significant indications to the regional tectonic time-space sequence and Micangshan basement-involved thrusting characteristics. In this paper, the anticline's south limb rotating growth strata within the Middle-Upper Jurassic, based on interpretation of two geological section, is featured, indicating that the folding of the strata started around the late Middle Jurassic-Early Late Jurassic and together with the interpretation of long seismic profile, we believe that basement-involved wedge-thrusting structure style is developed in Micangshan structure belt and the basin-ward movement of the displacement of the wedge tip along the Pre-sinian detachment layer results in the formation of the NE structure of Tongnanba anticline. Apatite fission track thermal simulation indicates that Tongnanba anticline started experiencing rapid uplifting and denudation in the early Late Cretaceous (95-90 Ma) and the Middle-Late Cenozoic (about 24 Ma) with uplift speed 0.06-0.085 mm/a and around 0.133 mm/a respectively. Through the summary of regional historical low temperature thermochronology data, geographical partition based tectonic time-space sequence is established, suggesting that northeastern Sichuan Basin experienced N-S basin-ward tectonic spreading from Micangshan structure belt and NE-SW tectonic super imposition from Dabashan structure belt during the Middle-Late Jurassic, Cretaceous and Eocene-Miocene respectively. © 2017, Science Press. All right reserved.  相似文献   

On the role of incompetent strata in the structural evolution of the Zagros Fold-Thrust Belt,Dezful Embayment,Iran     

《Marine and Petroleum Geology》2017

The Dezful Embayment is the most important fertile oil province of the Zagros Fold-Thrust Belt. It includes several incompetent strata as basal and intermediate décollement levels that play a significant role on the structural styles and hydrocarbon preservation. Based on the interpretation of seismic profiles, the influence of the Gachsaran Formation and the evaporitic Kalhur Member of the Asmari Formation on the geometry of deformation was investigated in different parts of the Dezful Embayment. Obtained results revealed that the thickness of the incompetent strata plays a crucial role in the formation and geometry of different types of fold structures (e.g. rounded, box, chevron, detachment fold) in the Dezful Embayment. There is a sharp difference between the geometry of surface and deep-seated structures due to the existence of thick intermediate décollements (e.g. Gachsaran and Kalhur) in the Dezful Embayment. Therefore, fault geometry and fold styles in upper and lower parts of these décollements are totally different. In addition, these incompetent strata act as a barrier level against the propagation of deep-seated faults into the overlying layers. Therefore, it seems that most of the faults exposed on the surface have originated from the upper décollement levels in the study area.  相似文献   

长白沿江矿区勘查ZK0902孔施工技术          下载免费PDF全文

全志刚  王禹  杨春柳 《探矿工程》2010,37(4):34-36

长白沿江矿区钻探施工中遇到的主要问题是煤系地层水化膨胀,形成陷塘,钻孔坍塌、掉块,深部灰岩蚀变,形成溶洞,严重漏失,导致施工周期延长,现场及时分析原因,采用针对性的工艺措施,成功地解决了上述问题,圆满地完成了矿区施工任务。  相似文献   

湖北磷矿复杂地层深孔钻探施工工艺   总被引：1，自引：0，他引：1       下载免费PDF全文

胡成涛  郑门关  周红心  许华松 《探矿工程》2010,37(11):19-21

介绍了湖北兴山磷矿复杂地层深孔钻探施工工艺。针对复杂地层合理选择了钻头和钻进工艺参数;对破碎孔段采用优质泥浆钻进后,下套管稳定孔壁;对坍塌、掉块严重的孔段采用水泥浆封孔固壁;同时合理选择了绳索取心钻具,利用XY-5型钻机,完成了复杂地层1930 m深孔钻探任务。  相似文献   

Organic geochemical evaluation of the oil/gas-generative potential of organic matter in Cretaceous strata from the Lower Benue Trough,Nigeria     

Minapuye I.Odigi  Levi C.Amajor 《中国地球化学学报》2010,29(3):233-241

An analytical procedure involving Rock-Eval pyrolysis of whole-rocks was adopted on fresh outcrop samples covering the three lithostratigraphic units in the Afikpo Basin of the Lower Benue Trough. Three petroleum systems are present in the Cretaceous delta frame: the Asu-River Group, the Eze-Aku Group and proto-Niger Delta sequences. The Afikpo Basin has been correlated to three petroleum systems in the Lower Congo Basin, Niger Delta and the Anambra Basin. The organic geochemistry of the shales, carbonaceous mudstones and coal beds show relatively moderate to high total organic carbon contents. The best potential hydrocarbon source rocks are the Eze-Aku Group and proto-Niger Delta shales, carbonaceous mudstones and coal beds where maturation was attained. The high total or-ganic contents, thermal maturity and terrigenous characters of the Asu-River Group, Eze-Aku Group and proto-Niger Delta sediments, suggest the presence of a large amount of natural gas with a small quantity of oil accumulation. Variations in source rock facies were observed from one lithostratigraphic unit to another, and initial HI values as a function of TOC were proposed for each lithostratigraphic unit. The results also show that TOC, HI, OI, S2 and Tmax vary from older to younger rocks. The Tmax values discriminate the rocks into immature and mature source rocks. Source rocks with high Tmax suggest high geothermal gradient/or recycled organic matter. Also high Tmax and S2 yield indicate late and post maturity. Recycled organic matter is characterized by low Tmax. The principal source rocks for gas in the Afikpo Basin are the Eze-Aku Group and proto-Niger Delta beds deltaic systems, consisting mainly of III to IV kerogens with a subordinate amount of type II organic matter. Based on the obtained results, it is concluded that the Cretaceous shales, carbonaceous mudstones and coals in the Afikpo Basin of the Lower Benue Trough are capable of generating and expelling hydrocarbons in the case of sufficient maturity.  相似文献   

Effects of Near-Surface Absorption on Reflection Characteristics of Continental Interbedded Strata: the Dagang Oilfield as an Example   总被引：1，自引：0，他引：1  

LI Guof  CAO Mingqiang  ZHOU Hui 《《地质学报》英文版》2010,84(5):1306-1314

<正>Due to the effects of seismic wave field interference,the reflection events generated from interbedded and superposed sand and shale strata no longer have an explicit corresponding relationship with the geological interface.The absorption of the near-surface layer decreases the resolution of the seismic wavelet,intensifies the interference of seismic reflections from different sand bodies,and makes seismic data interpretation of thin interbedded strata more complex and difficult. In order to concretely investigate and analyze the effects of the near-surface absorption on seismic reflection characteristics of interbedded strata,and to make clear the ability of current technologies to compensate the near-surface absorption,a geological model of continental interbedded strata with near-surface absorption was designed,and the prestack seismic wave field was numerically simulated with wave equations.Then,the simulated wave field was processed by the prestack tune migration, the effects of near-surface absorption on prestack and poststack reflection characteristics were analyzed,and the near-surface absorption was compensated for by inverse Q-filtering.The model test shows that:(1) the reliability of prediction and delineation of a continental reservoir with AVO inversion is degraded due to the lateral variation of the near-surface structure;(2) the corresponding relationships between seismic reflection events and geological interfaces are further weakened as a result of near-surface absorption;and(3) the current technology of absorption compensation probably results in false geological structure and anomaly.Based on the model experiment,the real seismic data of the Dagang Oil Field were analyzed and processed.The seismic reflection characteristics of continental interbedded strata were improved,and the reliability of geological interpretation from seismic data was enhanced.  相似文献   

苏北盐阜地区中、古生界地层分布特征     

石胜群 《地层学杂志》2010,34(1)

应用钻井、测井及古生物资料,对下扬子苏北盐阜地区中、古生界地层进行研究,同时综合了重、磁、电、二维地震、MT二维剖面等资料,探讨盐阜地区中生界残留地层展布规律。研究结果表明,中生界白垩系浦口组在研究区广泛分布,厚度较大,且分布稳定,而赤山组、葛村组及侏罗系、三叠系局部零星分布;上古生界地层残存在滨海隆起—建湖隆起引水沟凸起一带,下古生界地层残存在淮阴凹陷—盐城凹陷地区。  相似文献   

贵州桐梓县境南部奥陶系-志留系界线地层新认识   总被引：2，自引：0，他引：2  

戎嘉余  陈旭  詹仁斌  樊隽轩  王怿  张元动  李越  黄冰  吴荣昌  王光旭  刘建波 《地层学杂志》2010,34(4)

贵州桐梓红花园山王庙的奥陶系-志留系分界地层出露好、有笔石带控制且发育介壳相化石,一直被认为是华南最佳剖面之一。本文对该剖面重新剖析,结合桐梓县境南区另外几条剖面的资料分析,提出如下新认识:山王庙剖面的"赫南特贝层"(HirnantiaBed:AFA295-305)和"介壳层"(Shelly Bed:AFA306-311c)宜合并统称为观音桥层,皆归于奥陶系;对照宜昌王家湾,将观音桥层与Normalograptus extraordinarius带上部和N.persculptus带下部对比;确定观音桥层与龙马溪组之间缺失N.persculptus带上部、A.ascensus带和P.acuminatus带大部分的地层。典型赫南特贝动物群延至A.ascensus带甚至更高层位的观点应予以修正。靠近黔中古陆北缘的诸多地点,观音桥层的厚度虽有变化,均宜视为同期沉积,唯上覆地层时代不同。赫南特贝动物群是在特定时期、特定环境中生存的特定底栖生物群落,是奥陶纪末大灭绝首幕后的产物,指示了寒凉、海退、相对浅水、底域富氧的环境条件,有重要的时代、环境和古地理意义。  相似文献   

狮子庙金矿田复杂地层护壁技术探索     

石得权 《地质与勘探》2010,46(Z1):1301-1304

[摘要]本文通过对狮子庙金矿田地层特点的分析,对矿田地层科学地进行了分类,针对不同类 型的地层,从护壁机理、钻具级配和钻进参数等方面入手,探索和研究出了不同的泥浆配方,改进钻头级 配,有效地解决了该地区的钻探施工技术难题,降低了事故率,提高了钻进效率。  相似文献