Biostratigraphy,Depositional and Diagenetic Processes in Carbonate Rocks from Southern Lebanon: Impact on Porosity and Permeability     

Hammad Tariq JANJUHAH  Josep SANJUAN  Mohammad ALQUDAH  Mohamed K. SALAH 《《地质学报》英文版》2021,95(5):1668-1683

Carbonate rocks contain prolific hydrocarbon reserves all over the world, particularly in the Middle East. For exploration and production strategies, it is essential to understand carbonate reservoirs in terms of their internal characteristics, depositional environment, relative age, diagenetic processes and impact on petrophysical properties. This study has been performed on exposed Cretaceous, Paleocene and Miocene marine carbonate sedimentary sequences in two localities (Maghdoucheh and Qennarit) near the city of Sidon (Southern Lebanon). It represents the first comprehensive study that takes into consideration the carbonate reservoir facies, diagenetic history and reservoir quality in the area. Rocks at Maghdoucheh are mainly dominated by limestone beds showing sedimentary structures and erosive bases alternating with microfossil-rich silty marls, related to a shallowing upward sequence in a restricted marine platform environment. Shells of benthic foraminifera and mollusks dominate the fossil assemblage extracted from the studied rocks. The microfossil and nannofossil assemblage detected in the Maghdoucheh sections indicates a middle Miocene age. Rocks at Qennarit are composed of mudstone/wackestone limestone beds rich in planktonic foraminifera and nannofossils related to open marine conditions. Based on the nannofossil content, rocks from Qennarit 1 and 2 are Paleocene and Cretaceous in age, respectively. Four main types of microfacies have been identified, i.e. (1) microbioclastic peloidal calcisiltite, (2) pelagic lime mudstone and wackestone with planktonic microfossils, (3) grainstone/packstone with abundant foraminifera and (4) fenestral bindstones, mudstones and packstones with porostromate microstructures. The porosity-permeability (poro-perm) analysis of representative samples reveals moderate to good porosity but very low permeability. This is mainly due to the presence of large moldic pores that are isolated in nature. The diagenetic features are dominated by micritization and dissolution (both fabric selective and non-fabric selective). Among all diagenetic features, dissolution in both localities contributes to porosity enhancement, while micritization, cementation, compaction and the filled fractures have negative impacts on permeability; hence the overall reservoir quality.  相似文献   

Oldest Asian Record of Snapping Shrimps (Malacostraca: Alpheidae) from the Kutch Basin, Western India and Associated Biota: Biostratigraphic, Paleoenvironmental and Paleoecological Significance     

Vivesh V. KAPUR  Kamlesh KUMAR  Pranav J. PANDYA  Amit K. GHOSH  Arindam CHAKRABORTY  Anupam SHARMA  Gaurav CHAUHAN  M. G. THAKKAR 《《地质学报》英文版》2022,96(6):1867-1883

The oldest Asian record of alpheid shrimps, assigned to genus Alpheus, based on snapping claw fingertips from the Miocene Khari Nadi Formation in the Kutch Basin, western India reported herein, extends the fossil record of the family Alpheidae from Asia by ~22 million years. An early Miocene (Aquitanian) age is estimated based on the associated assemblage of calcareous nannofossils, Sphenolithus disbelemnos, Cyclicargolithus floridanus, and Reticulofenestra haqii. The co-occurring microbiota includes bony fish otolith remains, identified as “genus Gobiidarum”, isolated teeth of Dasyatis rays, Sphyrna sharks, and teleosts, ctenoid and placoid scales, ostracods, belonging to the genera Paractinocythereis, Alocopocythere, Ruggieria? Aglaiocypris, Bairdoppilata, and echinoid spines. Taken together, the microfossil assemblage and data from chemical analyses using Energy Dispersive Spectroscopy, X-Ray Diffraction and Wavelength Dispersive X-Ray Fluorescence of host and associated lithologies suggests prevalence of a shallow (neritic) to coastal marine (intertidal) depositional paleoenvironment.  相似文献   

基于CMIP5模拟预估21世纪珠江三角洲地区由于海平面上升而导致的淹没区面积     

夏江江  严中伟  周文  FONG Soi Kun  LEONG Ka Cheng  TANG Iu Man  CHANG S W  LEONG W K  靳少非 《海洋学报(英文版)》2015,34(9):78-84

Projections of potential submerged area due to sea level rise are helpful for improving understanding of the influence of ongoing global warming on coastal areas. The Ensemble Empirical Mode Decomposition method is used to adaptively decompose the sea level time series in order to extract the secular trend component. Then the linear relationship between the global mean sea level(GMSL) change and the Zhujiang(Pearl) River Delta(PRD)sea level change is calculated: an increase of 1.0 m in the GMSL corresponds to a 1.3 m(uncertainty interval from1.25 to 1.46 m) increase in the PRD. Based on this relationship and the GMSL rise projected by the Coupled Model Intercomparison Project Phase 5 under three greenhouse gas emission scenarios(representative concentration pathways, or RCPs, from low to high emission scenarios RCP2.6, RCP4.5, and RCP8.5), the PRD sea level is calculated and projected for the period 2006–2100. By around the year 2050, the PRD sea level will rise 0.29(0.21 to 0.40) m under RCP2.6, 0.31(0.22 to 0.42) m under RCP4.5, and 0.34(0.25 to 0.46) m under RCP8.5, respectively.By 2100, it will rise 0.59(0.36 to 0.88) m, 0.71(0.47 to 1.02) m, and 1.0(0.68 to 1.41) m, respectively. In addition,considering the extreme value of relative sea level due to land subsidence(i.e., 0.20 m) and that obtained from intermonthly variability(i.e., 0.33 m), the PRD sea level will rise 1.94 m by the year 2100 under the RCP8.5scenario with the upper uncertainty level(i.e., 1.41 m). Accordingly, the potential submerged area is 8.57×103 km2 for the PRD, about 1.3 times its present area.  相似文献   

Inter-annual and seasonal variations in hydrological parameters and its implications on chlorophyll a distribution along the southwest coast of Bay of Bengal     

Shanthi R.  Poornima D.  Raja K.  Sarangi R. K.  Saravanakumar A.  Thangaradjou T. 《海洋学报(英文版)》2015,34(6):94-100

Seasonal and inter-annual variability of hydrological parameters and its impact on chlorophyll distribution was studied from January 2009 to December 2011 at four coastal stations along the southwest Bay of Bengal. Statistical analysis(principal component analysis(PCA), two-way analysis of variance(ANOVA) and correlation analysis)showed the significant impact of hydrological parameters on chlorophyll distribution in the study area. The ranges of different parameters recorded were 23.8–33.8°C(SST), 4.00–36.00(salinity), 7.0–9.2(p H), 4.41–8.32 mg/L(dissolved oxygen), 0.04–2.45 μmol/L(nitrite), 0.33–16.10 μmol/L(nitrate), 0.02–2.51 μmol/L(ammonia),0.04–3.32 μmol/L(inorganic phosphate), 10.09–85.28 μmol/L(reactive silicate) and 0.04–13.8 μg/L(chlorophyll).PCA analysis carried out for different seasons found variations in the relationship between physico-chemical parameters and chlorophyll in which nitrate and chlorophyll were positively loaded at PC1(principal component1) during spring inter-monsoon and at PC2(principal component 2) during other seasons. Likewise correlation analysis also showed significant positive relationship between chlorophyll and nutrients especially with nitrate(r=0.734). Distribution of hydrobiological parameters between stations and distances was significantly varying as evidenced from the ANOVA results. The study found that the spatial and temporal distribution of chlorophyll was highly dependent on the availability of nutrients especially, nitrate in the southwest Bay of Bengal coastal waters.  相似文献   

从构造形成的新旋转假说观点看构造圈的形变规律     

K.  F.  加波金 《地质力学学报》1997,3(3):90-96

本文是为中国地球科学研究者而写的。文中介绍了地球构造圈构造形成的新的旋转假说及其一些成果:构造圈断块性和断裂继承性活动的规律。   相似文献   

安徽月山岩体的40Ar/39Ar年龄及与其有关的成矿时代估计   总被引：13，自引：0，他引：13  

陈江峰  李学明  周泰禧  K.A.Foland 《现代地质》1991,5(1):91-99

安徽月山岩体是长江中下游钢铁成矿带中的一个重要含矿岩体.我们对该岩体的角闪石和黑云母进行了⁴⁰Ar/³⁹Ar年龄测定.角闪石的未扰动年龄谱给出岩体侵位年龄为136Ma.根据黑云母的扰动年龄谱,估计岩体从浸位到矿化（晚期热液作用）的时间间隔不少于9Ma.月山岩体的年龄测定结果以及前人对长江中下游其它含铜岩体的年龄测定结果表明,该区所有铜矿化岩体均形成于136Ma前,且产出于沿江构造单元内.此外,月山岩体的研究还表明,对中酸性岩的年龄测定,封闭温度高的角闪石是较理想的样品,在解释与矿化有关或热液作用发育的岩体的黑云母K-Ar结果时,必须持慎重态度.  相似文献   

Direct scaling of residual displacements for bilinear and pinching oscillators     

Mohammad Saifullah  Vinay K.Gupta 《地震工程与工程振动(英文版)》2024,(1):129-149

The estimation of residual displacements in a structure due to an anticipated earthquake event has increasingly become an important component of performance-based earthquake engineering because controlling these displacements plays an important role in ensuring cost-feasible or cost-effective repairs in a damaged structure after the event. An attempt is made in this study to obtain statistical estimates of constant-ductility residual displacement spectra for bilinear and pinching oscillators wit...  相似文献   

21世纪的世界石油资源     

K.  ЮИ 朱佛宏 《海洋地质前沿》2000,16(7):6-8

预测世界石油资源不仅确定了局部区域的能源潜力 ,还有其战略意义。２０世纪最为现实的工作是多次计算了石油的潜在资源 ,而且 ,最新计算的油气资源量通常超过以前的计算 ,并总是因发现以石油、凝析气等不同相态存在的新油田而得到证实。如在２０世纪初 ,П．Уикс确定世界石油资源总量为９５亿ｔ,但到１９５８年已增至２０７０亿ｔ,而到世纪末估计有５４００亿ｔ。在石油资源评价上有如此大的进展与烃类普查方法的完善 ,在油气生成领域内理论工作的成功 ,地球物理和地球化学研究的应用以及在成因基础上对含油气性前景论证的充分有关。…  相似文献   

搭建地震方法和大地测量方法所检测的慢地震之间的桥梁     

S.Ide  K.Imanishi  Y.Yoshida  G.C.Beroza  D.R.Shelly  陈婷 《世界地震译丛》2009,(1):21-27

最近观测到的异常地震事件——深部低频地震和颤动、甚低频地震及慢滑动事件——形成了慢震群,而这个慢震群受控于不同于普通地震的标定律。根据这个标定律,我们在日本西部的纪伊半岛下方观测到了之前未知的事件,其震源持续时间约20-200s,矩震级为3～4级。这些地震在2～8Hz的频带范围内辐射能量,直接与其地震矩率成比例,但这个比例常数比一般地震小4～5个数量级。这个地区的慢地震可能是由大量的剪切滑动事件组成的,从地震方法上看,总体上会呈现为颤动或长达200s持续时间的较长独立事件,从大地测量方法上看,是慢滑动事件。  相似文献   

2004年苏门答腊—安达曼M9级地震的下一代形变模型     

T.Masterlark  K.L.H.Hughes  张华 《世界地震译丛》2009,(3):24-29

2004年的苏门答腊—安达曼M9级地震将俯冲的印度—澳大利亚板块和仰冲的缅甸板块分裂开。这次地震的形变属于三维问题,为此我们构建了有限元模型进行模拟,以说明俯冲板块、弧前、火山弧及弧后的物性分布。同震形变的模拟使用一种基于协议的方法。该方法考虑俯冲带的地质复杂性,使用有限元模型反演估计断层滑动分布。结果表明不考虑俯冲带中物性差异的形变预测的灵敏度比近场GPS的测量误差可大一个数量级还多。本文介绍的基于有限元模型的技术可用于地质上相符的形变模型,提高同震与震后形变、应力耦合及海啸发生的基于模拟技术的评估可靠性。  相似文献