莱州湾东岸三山岛段砂质海岸沉积物运移动力机制   总被引：1，自引：0，他引：1       下载免费PDF全文

刘世昊  丰爱平  杜军  夏东兴  胡维芬  李平 《海洋科学进展》2014,32(3)

通过对三山岛岸段冬夏重复的地形测量和表层沉积物的粒度分析,研究了其地貌特征与地形变化规律、沉积物类型、粒度特征、运移趋势,并探讨了沉积物运移的动力机制。结果表明:该岸段可根据1985黄海高程-1.2m(低潮水位)和-6.5m(闭合深度)平面划分为海滩、水下岸坡和浅海陆架三个地貌单元,各地貌单元表层沉积物分布规律与地形变化特征区别显著。其中水下岸坡和浅海陆架地貌单元主要受潮流作用,海滩地貌单元主要受波浪作用。在西向落潮流和西南向潮余流的作用下,水下岸坡地貌单元发育一个中等规模潮流通道-沙脊沉积系统。表层沉积物以向西运移的趋势为主,少数滞留于西部潮流沙脊处,与地形"东侵西淤"的变化规律相符,这些西向运移的沉积物最终离开研究区,补给莱州浅滩。  相似文献   

Multi-sourced depositional sequences in the Neogene to Quaternary succession of the Venice area (northern Italy)     

《Marine and Petroleum Geology》2014

The Plio-Pleistocene succession of the Venice area represents part of the infill of a foreland region located between three mountain chains: the Northern Apennines, the Southern Alps and the Dinarides. This structural setting favored the development of a complex stratigraphic architecture of the succession, mostly due to the conveying of sediments from the Southern Alps to the north and the Northern Apennines to the south, in particular since the activation of strong subsidence related to the NE-ward migration of the Apennine foredeep in the early Pleistocene. Accordingly, the studied succession is composed of five third-order sequences mostly controlled by tectonics, the most recent of which display complex patterns due to the interfingering of sedimentary bodies showing contrasting directions of progradation and pinch-out. Despite this, the sequence stratigraphic method still can be applied in the present context, allowing to recognize diagnostic stratal architectures and reconstruct the relative sea-level history of the region. Moreover, the recognized peculiar stratigraphic architecture of the basin fill may serve as an analogue that needs to be taken into account to predict the distribution of porous coarse-grained sedimentary units in similar contexts, aiding for a profitable exploration and production of reservoirs and source/sealing rocks.  相似文献   

Late Pleistocene–Holocene seismic stratigraphy of Nha Trang shelf,central Vietnam     

《Marine and Petroleum Geology》2014

The late Pleistocene–Holocene stratigraphic architecture on the steep and narrow shelf off Nha Trang, central Vietnam has been explored by high resolution seismic profiles integrated with sediment core data. Sequence stratigraphic results reveal five major seismic units and three bounding surfaces which are composed of two distinctive sequences. Those sequences are bounded by two regional unconformities (SB1, SB2) which have been formed in respond to different sea-level regimes. The revealed relict beach–ridge deposits at water depth of about ∼130 m below the present water depth indicate that the Last Glacial Lowstand (LGM) sea-level in this area was lower than in neighboring areas and it probably resulted from subsidence due to high sedimentation rate and/or neotectonic movements of the East Vietnam Fault System. The late Pleistocene high amplitude of sea-level change during a long fourth-order and superimposed by shorter fifth-order cycle is the principal factor in reorganizing the formation of the Nha Trang continental shelf sequence. Other local controlling factors as fluctuations in sediment supply, morphological variations of the LGM surface, subsidence rate and hydrodynamic conditions provided the distinctive features of the Nha Trang shelf sequence stratigraphic model in comparison with neighboring other areas.  相似文献   

黄河口凹陷流体包裹体成藏年代和充注期次研究   总被引：1，自引：0，他引：1  

胡雄  梁为  李洋冰  朱学光  黄伟强  侯厶靖  徐博瑞 《矿物岩石地球化学通报》2014,33(6)

流体包裹体技术已被证实在含油气盆地的成藏年代和运移期次的研究中是一个有效的手段。关于包裹体在成藏期次方面的研究已有许多,但系统介绍包裹体技术在油气勘探中的应用研究则少见。为推动该方法在油气勘探中的应用,本文从样品制备、分析仪器、流体包裹体镜下特征、均一温度等方面系统介绍了利用流体包裹体确定油气成藏年代与充注期次的方法,以及该方法在黄河口凹陷油气勘查中的应用研究成果:确定了该凹陷普遍发育较低成熟液态烃包裹体、成熟气液态烃包裹体、较高成熟气液态烃包裹体和气烃包裹体3类包裹体,确定了黄河口地区沙河街组油气充注至少有3期:第1期、第2期油气于明化镇组沉积时期开始注入储层(10~5Ma),第3期较高成熟油及伴生气于第四纪开始注入储层(小于3Ma);利用包裹体均一温度还确定了位于黄河口凹陷与渤中凹陷交界的BZ25构造第1期油气来源于渤中凹陷。  相似文献   

Unraveling rift margin evolution and escarpment development ages along the Dead Sea fault using cosmogenic burial ages     

A. Matmon  D. Fink  M. Davis  S. Niedermann  D. Rood  A. Frumkin 《Quaternary Research》2014

The Dead Sea fault (DSF) is one of the most active plate boundaries in the world. Understanding the Quaternary history and sediments of the DSF requires investigation into the Neogene development of this plate boundary. DSF lateral motion preceded significant extension and rift morphology by ~ 10 Ma. Sediments of the Sedom Formation, dated here between 5.0 ± 0.5 Ma and 6.2_− 2.1^+ inf Ma, yielded extremely low ¹⁰Be concentrations and ²⁶Al is absent. These reflect the antiquity of the sediments, deposited in the Sedom Lagoon, which evolved in a subdued landscape and was connected to the Mediterranean Sea. The base of the overlying Amora Formation, deposited in the terminal Amora Lake which developed under increasing relief that promoted escarpment incision, was dated at 3.3_− 0.8^+ 0.9 Ma. Burial ages of fluvial sediments within caves (3.4 ± 0.2 Ma and 3.6 ± 0.4 Ma) represent the timing of initial incision. Initial DSF topography coincides with the earliest Red Sea MORB's and the East Anatolian fault initiation. These suggest a change in the relative Arabian–African plate motion. This change introduced the rifting component to the DSF followed by a significant subsidence, margin uplift, and a reorganization of relief and drainage pattern in the region resulting in the topographic framework observed today.  相似文献   

贵州晴隆中二叠统大厂层砾岩成因研究   总被引：1，自引：0，他引：1  

陈军  杨瑞东  郑禄林  高军波  魏怀瑞 《地质论评》2014,60(6):1309-1322

贵州晴隆中二叠统大厂层中—上部产出一套呈囊状、透镜状分布的砾岩层。对大厂层砾岩沉积序列、结构、构造特征和矿物组合进行研究,结果表明:沉积序列为"反粒序",砾岩成分单一,基本为玄武质,是由峨眉山玄武岩直接改造而成,未发育河道相沉积特征;大厂层砾石具特殊的"泥化边"构造,是玄武岩在海水中大量水解的直接证据,填隙物中的青磐岩化矿物组合表明砾岩遭受了低温热液的改造。填隙物具有接近凝灰岩的Zr/Hf(30.7~43.4,均值38.0),揭示玄武岩在改造形成砾石的过程中有火山碎屑(火山灰)参与成岩;砾石和填隙物相对玄武岩贫Na(Na2O)富K(K2O),三者具有相似的稀土配分模式,其中∑REE呈规律性变化(玄武岩最高,砾石次之,填隙物中最低)。沉积背景分析认为,峨眉地幔柱作用使地壳发生了差异抬升,抬升一侧暴露遭受剥蚀形成不整合面,相对沉降一侧继续接受沉积,大厂层正是峨眉山玄武岩前锋带在局限海盆边缘(沉降侧),于茅口灰岩之上继续沉积的产物。大厂层砾岩形成机制是:炽热玄武岩流在海水中急剧爆裂,同时火山碎屑参与沉积,形成的玄武岩前积层(淬碎熔岩角砾)及凝灰岩,沉积在茅口组灰岩之上;在后期的演化过程中,炽热玄武岩冷凝收缩,柱状节理发育,在潮汐流和沿岸流的相互作用下不断磨蚀形成大厂层砾岩。  相似文献   

轻度沙埋对典型荒漠植物的影响北大核心CSCD     

赵春彦  秦洁  贺晓慧  周冬蒙 《中国沙漠》2022,42(5):63-72

中国西北干旱区以荒漠生态系统为主体,是中国典型脆弱生态系统。沙埋对该区域植物生存和生长、植被分布和组成以及荒漠生态系统功能和结构有重要影响。以典型荒漠植物梭梭(Haloxylon ammodendron)、柽柳(Tamarix chinensis)、白刺(Nitraria tangutorum)、沙拐枣(Calligonum mongolicum)为研究对象,对比研究了轻度沙埋和非沙埋植物在生理和生长方面的差异,并从土壤盐分、土壤水分、土壤温度等方面探究了造成这种差异的原因。结果表明:轻度沙埋环境下,梭梭、柽柳、白刺、沙拐枣的光合速率普遍高于非沙埋植株,蒸腾速率显著低于非沙埋植株,水分利用效率也均高于非沙埋植株。轻度沙埋梭梭、柽柳、沙拐枣、白刺株高明显低于非沙埋植株,但地径、冠幅、叶面积指数普遍高于非沙埋植株。主要原因是轻度沙埋植物下方土壤黏粒含量、土壤湿度高于非沙埋植物下方,轻度沙埋植物下方土壤温度、含盐量低于非沙埋环境。  相似文献   

Chemical and physical properties affecting strontium distribution coefficients of surficial-sediment samples at the Idaho National Engineering and Environmental Laboratory, Idaho     

M. J. Liszewski  J. J. Rosentreter  K. E. Miller  R. C. Bartholomay 《Environmental Geology》2000,39(3-4):411-426

 The U.S. Geological Survey and Idaho State University, in cooperation with the U.S. Department of Energy, conducted a study to determine strontium distribution coefficients (K_ds) of surficial sediments at the Idaho National Engineering and Environmental Laboratory (INEEL). Batch experiments using synthesized aqueous solutions were used to determine K_ds, which describe the distribution of a solute between the solution and solid phase, of 20 surficial-sediment samples from the INEEL. The K_ds for the 20 surficial-sediment samples ranged from 36 to 275 ml/g. Many properties of both the synthesized aqueous solutions and sediments used in the experiments also were determined. Solution properties determined were initial and equilibrium concentrations of calcium, magnesium, and strontium, pH and specific conductance, and initial concentrations of potassium and sodium. Sediment properties determined were grain-size distribution, bulk mineralogy, whole-rock major-oxide and strontium and barium concentrations, and Brunauer-Emmett-Teller (BET) surface area. Solution and sediment properties were correlated with strontium K_ds of the 20 surficial sediments using Pearson correlation coefficients. Solution properties with the strongest correlations with strontium K_ds were equilibrium pH and equilibrium calcium concentration correlation coefficients, 0.6598 and –0.6518, respectively. Sediment properties with the strongest correlations with strontium K_ds were manganese oxide (MnO), BET surface area, and the >4.75-mm-grain-size fraction correlation coefficients, 0.7054, 0.7022, and –0.6660, respectively. Effects of solution properties on strontium K_ds were interpreted as being due to competition among similarly charged and sized cations in solution for strontium-sorption sites; effects of sediment properties on strontium K_ds were interpreted as being surface-area related. Multivariate analyses of these solution and sediment properties resulted in r² values of 0.8071 when all five properties were used and 0.8043 when three properties, equilibrium pH, MnO, and BET surface area, were used. Received: 30 November 1998 · Accepted: 16 February 1999  相似文献   

渤海湾盆地黄骅坳陷石炭系—二叠系烃源岩生烃演化及与中—新生代构造演化的响应关系          下载免费PDF全文

马妍  孙永河  柳少波  马钰凯  刘海涛  赵长毅 《地质论评》2023,69(2):496-512

渤海湾盆地石炭系—二叠系为烃源岩的古生界潜山内幕型原生油气藏认识程度低,勘探难度大,明确石炭系—二叠系烃源岩生烃演化过程及与中—新生代构造演化的响应关系对内幕型原生油气藏勘探具有重要意义。笔者等基于三维地震资料、典型井实测镜质体反射率、流体包裹体等数据资料,进一步采用构造解析、潜山埋藏史分析以及盆地生烃模拟等技术手段,探讨了渤海湾盆地黄骅坳陷中—新生代构造运动及对石炭系—二叠系烃源岩生烃演化的控制作用,明确了生烃时期及有利生烃范围。研究表明,黄骅坳陷中—新生代构造活动经历了“两期裂陷,两期抬升”的四个演化阶段,形成多种类型的埋藏史,构造运动引起的古地温变化使南北地区烃源岩进行差异了生烃演化,裂陷建造作用促进地温上升,有利于有机质生烃,挤压改造作用抑制地温上升,有机质生烃中止。乌马营潜山及歧北潜山具有3次生烃阶段,生烃期为早—中三叠纪、早白垩纪、古近纪,港北潜山具有两次生烃阶段,生烃期为早—中三叠纪、古近纪。黄骅坳陷内早期(即早—中三叠纪)生烃范围局限,晚期(即古近纪)生烃最有利,乌马营地区及歧北地区为原生油气藏有利勘探区。  相似文献   

Invisible face of COVID-19 pandemic on the freshwater environment: An impact assessment on the sediment quality of a cross boundary river basin in Turkey     

Cem Tokatlı 《国际泥沙研究》2022,37(2):139-150

In the current research,the impact of the COVID-19 lockdown period on sediment quality of the MericErgene River Basin was evaluated by determining the potentially toxic elements（PTEs） in sediment samples collected from 25 sampling points in the basin.Also some important ecological indicators including potential ecological risk index（PERI）,contamination factor（CF）,pollution load index（PLI）,biological risk index（BRI）,and geo-accumulation index(I_geo) and some important statistical indica...  相似文献