塔里木盆地南部塘古孜巴斯坳陷发现晚新生代伸展构造   总被引：1，自引：0，他引：1       下载免费PDF全文

杨素举 马庆佑李曰俊黄太柱  吕海涛文磊张  强孟庆龙陈跃赵  岩贾铁干赵甜玉 《地质科学》2017,(2):317-327

通过认真、系统的地震资料解释,在塔里木盆地南部的塘古孜巴斯坳陷及周缘首次发现晚新生代正断层。在塘古孜巴斯坳陷内部发现的晚新生代正断层走向为北西-南东向,剖面上组合成地堑或堑-垒构造,与巴楚隆起东北缘所发育的晚新生代正断层相似。塘古孜巴斯坳陷西北缘发现的两条晚新生代正断层走向为北东-南西,剖面组合成一地堑构造,与阿瓦提凹陷西北缘沙井子断裂带上发育的晚新生代张扭性正断层带走向一致,但不具备张扭性变形特征。正断层形成于上新世晚期(约3 Ma),持续演化至更新世早期(约2 Ma)。正断层的活动时间也与阿瓦提凹陷周缘的晚新生代正断层一致。它们形成于一个区域性弱伸展构造应力场内,代表印度-亚洲碰撞远程效应下,塔里木盆地脉式挤压(-冲断)过程中的一个构造间歇期。  相似文献   

滇西户撒盆地芒棒组砂岩地球化学特征及物源区和构造背景分析     

张建军  牟传龙  周恳恳  冯丽霞  伍皓  陈小炜 《地质学报》2017,91(5):1083-1096

滇西户撒盆地芒棒组砂岩地球化学分析结果表明:砂岩主要为长石砂岩和杂砂岩,少量为页岩;矿物成分主要为石英、钾长石、斜长石和伊利石等;REE配分模式曲线一致,LREE/HREE=9.75～15.91,平均13.24,(La/Yb)_N=13.06～26.41,平均19.21,轻稀土元素相对重稀土元素明显富集,稀土元素分馏明显。SiO_2/Al_2O_3=2.06～6.01,平均4.60,ICV=0.54～1.09,平均0.86,结合沉积特征表明样品为被动构造环境下沉积物的再循环而成,而非强烈风化作用过程中形成的第一次旋回沉积物。Th/U=5.44～12.10,平均8.48,CIA矫正均值为69,反映了温暖、湿润条件下的中等化学风化作用。A-CN-K判别图说明交代作用降低了CIA值、且样品源岩钾长石比斜长石含量高。Th/Sc=4.43～25.35,平均8.18,Rb-K_2O图解、Co/Th-La/Sc图解和La/Yb-∑REE图解表明样品物源为花岗岩。TiO_2-(Fe_2O_3T+MgO)、Al_2O_3/(Cao+Na_2O)-(Fe_2O_3T+MgO)、La-Th-Sc以及(K_2O/Na_2O)-SiO_2构造判别图解表明:源岩形成于被动大陆边缘环境,与中特提斯洋在晚侏罗世—早白垩世已经打开且长期稳定相对应。户撒盆地为沿早期户撒走滑-挤压断裂拉张沉积形成,接受周缘晚侏罗世—早白垩世花岗岩沉积。  相似文献   

Geochemistry and provenance of a multiple-stage fan in the Upper Miocene to the Pliocene in the Yinggehai and Qiongdongnan basins,offshore South China Sea     

《Marine and Petroleum Geology》2017

The Yinggehai and Qiongdongnan basins in the northwestern South China Sea preserve a large volume of Cenozoic sediments. However, their sources are still remain controversial and need a further research. This paper uses discriminant diagrams and bivariate plots of major, trace and rare earth elements, combined with heavy mineral data and detrital zircon U-Pb ages to determine the provenance, source area weathering and tectonic setting of the Upper Miocene to Pliocene sediments in the Yinggehai and Qiongdongnan basins, offshore South China Sea. The sandstone samples used in this study are characterized by four features: (i) The studied sandstones are first-cycle deposits, no recycling processes are recorded in these sediments, and there is a low degree of weathering conditions in the source areas. (ii) The sandstones from the DF fan, LD fan and Central Canyon System may have a similar source, being derived from an old upper continental crust mainly composed of felsic igneous source rocks. (iii) Detrital zircon U-Pb ages suggest that Central Vietnam is likely to be the dominant source of the DF fan, LD fan and Central Canyon System. (iv) The tectonic setting of the sandstones in the DF fan, LD fan and Central Canyon System belongs to the continental island arc (CIA) or the active continental margin (ACM) fields.  相似文献   

The link between tectonics and sedimentation in asymmetric extensional basins: Inferences from the study of the Sarajevo-Zenica Basin     

《Marine and Petroleum Geology》2017

The coupled tectonic and depositional history of extensional basins is usually described in terms of stratigraphic sequences linked with the activity of normal faults. This depositional-kinematic interplay is less understood in basins bounded by major extensional detachments or normal fault systems associated with significant exhumation of footwalls. Of particular interest is the link between tectonics and sedimentation during the migration of normal faulting in time and space across the basin. One area where such coupled depositional-kinematic history can be optimally studied is the Late Oligocene - Miocene Sarajevo-Zenica Basin, located in the Dinarides Mountains of Bosnia and Herzegovina. This intra-montane basin recorded Oligocene – Pliocene sedimentation in an endemic and isolated lake environment. We use field kinematic and sedimentological mapping in outcrops correlated with existing local and regional studies to derive a high-resolution evolutionary model of the basin. The novel results demonstrate a close correlation between moments of normal faulting and high-order sedimentological cycles, while the overall extensional basin was filled by a largely uni-directional sediment supply from the neighbouring mountain chain. The migration in time and space of listric NE-dipping normal faults was associated with a gradual shift of the sedimentological environment. Transgressive-regressive cycles reflect sequential displacements on normal faults and their footwall exhumation, defining a new sedimentological model for such basins. This Early - Middle Miocene extension affected the central part of the Dinarides and was associated with the larger opening of the neighbouring Pannonian Basin. The extension was preceded and followed by two phases of contraction. The Oligocene - Early Miocene thrusting took place during the final stages of the Dinarides collision, while the post-Middle Miocene contraction is correlated with the regional indentation of the Adriatic continental unit. This latter phase inverted the extensional basin by reactivating the inherited basal listric detachment.  相似文献   

Sequence stratigraphy and depositional architecture of the Pearl River Delta system,northern South China Sea: An interactive response to sea level,tectonics and paleoceanography     

《Marine and Petroleum Geology》2017

Using a combined dataset including 3D seismic volumes, 2D profiles and 127 industrial wells, this study systematically investigated sequence stratigraphy and depositional architecture of the Pearl River Delta system (PRDS) during the Middle Miocene. In total, six stratigraphic sequences (SQ1 to SQ6) were recognized for the Hanjiang Formation, each of which could be further subdivided into a transgressive systems tract (TST) and a regressive systems tract (RST) according to a T-R sequence stratigraphic model. Seismic geomorphologic approaches were then conducted to interpret and map the key depositional elements, including fluvial channel systems, river mouth bars, longshore bars, shelf sand ridges and shelf sand sheets. After a detailed construction of the paleogeography for each of the twelves systems tracts, it was found that the types, geometries and depositional regimes of PRDS significantly altered at ca. 13.8 Ma. Before ca. 13.8 Ma, the PRDS were dominated by well-developed fluvial systems and an overall lobate shape, indicating a fluvial-dominated process. However, after 13.8 Ma, the whole PRDS began to form enormous shoreline-parallel depositional elements such as longshore bars, shelf sand ridges and shelf sand sheets, indicating dominant shore-parallel regimes. Besides, the whole deltaic system displayed obvious southwest deflection in map view after 13.8 Ma.Detailed analysis showed that this sudden change in the evolution of the PRDS could be ascribed to an interactive response to several factors. At ca. 13.8 Ma, the sea level began to rapidly rise and caused the fluvial energy to decrease, which was likely to lead to the diversion of the fluvial systems. Besides, the gradual uplift of the Dongsha Rise resulted in the raised shelf topography in the east region, thus confining the fluvial channels to flow southwestward. What's more, a few key paleoceanographic events, including the reglaciation of the Antarctic ice-sheet and the shoaling of the Pacific-Indian Ocean Seaway, might have contributed to the intensification of the southwesterly flowing paleocurrent along the northern South China Sea, thus triggering the delta asymmetry and deflecton of the PRDS after 13.8 Ma.  相似文献   

Utility of GOI,QGF, and QGF-E for interpreting reservoir geohistory and oil remigration in the Hudson oilfield,Tarim basin,northwest China     

《Marine and Petroleum Geology》2017

The physical mechanisms responsible for hydrocarbon migration in carrier beds are well understood. However, secondary migration is one of poorly understood facets in petroleum system. The Carboniferous Donghe sandstone reservoir in the Tarim Basin's Hudson oilfield is an example of a secondary (or unsteady) reservoir; that is, oil in this reservoir is in the process of remigration, making it a suitable geologic system for studying hydrocarbon remigration in carrier beds. Experimental methods including grains containing oil inclusions (GOI), quantitative grain fluorescence (QGF) and quantitative grain fluorescence on extract (QGF-E) -- together with the results from drilling, logging and testing data -- were used to characterize the nature of oil remigration in the Donghe sandstone. The results show that (1) significant differences exist between paleo- and current-oil reservoirs in the Donghe sandstone, which implies that oil has remigrated a significant distance following primary accumulation; (2) due to tectonic inversion, oil remigration is slowly driven by buoyancy force, but the oil has not entered into the trap entirely because of the weak driving force. Oil scarcely enters into the interlayers, where the resistance is relatively large; (3) the oil-remigration pathway, located in the upper part of the Donghe sandstone, is planar in nature and oil moving along this pathway is primarily distributed in those areas of the sandstone having suitable properties. Residual oil is also present in the paleo-oil reservoirs, which results in their abnormal QGF-E. A better understanding of the characteristics of oil remigration in the Donghe sandstone in the Hudson oilfield can contribute to more effective oil exploration and development in the study area.  相似文献   

利用小震与强震震源机制解反演首都圈现今构造应力场   总被引：5，自引：0，他引：5  

黄骥超  万永革 《地震》2015,35(1):17-27

由于首都圈地区近年来布设了较为密集的地震台网, 使得较小地震震源机制的求解成为可能。 本文收集了首都圈地区近50年来大震震源机制以及2002—2004年中小震震源机制解, 采用对不同震级地震进行加权处理的网格搜索法将强震与小震结合对首都圈地区的现今地壳应力场进行反演。 得到了较为精确的首都圈地区各区域的构造应力场。 结果表明: 北京张家口区, 主压应力轴N(43°～86°)E向; 唐山及邻区,主压应力轴N(38°～86°)E向; 邢台区, 主压应力轴N(79°～81°)E向; 本文反演结果与前人结果相似, 表明了研究方法的正确性, 并揭示了现今首都圈地区应力场的整体一致性和分区差异, 对解释首都圈地区的发震背景和地球动力学研究有一定的参考意义。  相似文献   

基于数字化水位的张渤带地区构造应力场时序特征分析   总被引：4，自引：0，他引：4  

丁风和  哈媛媛  王勇  魏建民  韩晓雷 《地震》2015,35(2):133-138

选取张渤带地区2008年以来连续稳定、固体潮形态明显的昌平台井、顺义板桥井、宝坻井、辛庄井、玉田冀03井、大灰厂井等6口井数字化水位及相应的气压资料。利用气压系数和M2波潮汐因子等滑动拟合,得到不排水状态下,各井含水层的孔隙度、固体骨架的体积压缩系数和水的体积压缩系数。接着在水平层状含水层(一维)模式下,利用部分含水层介质参数(孔隙度、水和固体骨架的体积压缩系数)、井水位变化量与含水层垂直向应力变化量的关系式,定量分析了张渤带地区构造应力场的动态变化过程。结果表明,张渤带近几年以持续的应力增强活动为主,今后需加强多学科、多手段的密切跟踪。  相似文献   

Recognition of shear heating on a long‐lived major fault using Raman carbonaceous material thermometry: implications for strength and displacement history of the MTL,SW Japan          下载免费PDF全文

Hiroshi Mori  Simon Wallis  Koichiro Fujimoto  Norio Shigematsu 《Island Arc》2015,24(4):425-446

The extent to which movement on major faults causes long term shear heating is a contentious issue and an important aspect in the debate about the strength of major faults in the crust. Comparing the results of experimental work on the kinetics of crystallization of carbonaceous material with results of thermal modeling show that the Raman carbonaceous material (CM) geothermometer is well suited to studying shear heating on geological time scales in suitable lithologies exposed around exhumed major fault zones. The Median Tectonic Line (MTL), SW Japan, is the largest on‐land fault in Japan with a length of > 800 km. Application of Raman CM thermometry to pelitic schist adjacent to the fault reveals the presence of a rise in peak temperature of around 60 °C over a distance of around 150 m perpendicular to the MTL fault plane. The spatial association of this thermal anomaly with the fault implies it is due to shear heating. Thermal modeling shows the recorded thermal anomaly and steep temperature gradient is compatible with very high rates of displacement over time scales of a few thousand years. However, the implied displacement rates lie outside those generally observed. An alternative explanation is that an originally broader thermal anomaly that developed during strike slip faulting was shortened due to the effects of normal faulting. Constraints on displacement rate, width of the original anomaly, duration of heating and peak temperature imply a coefficient of friction, μ, greater than 0.4.  相似文献   

Sea Levels and Western Boundary Flow Near a Tectonic Zone in the Northern Pacific     

Shigehisa Nakamura 《Marine Geodesy》2013,36(1):27-33

This article concerns an interrelation between the sea levels and the western boundary flow near a tectonic boundary in a local zone in the Northwestern Pacific. In this zone, sea level variations at stations located on the coast facing the Pacific are studied to find the interrelation between variations of the Kurosio flow as an index of the distance of the flow axis off a specific coast. The result is discussed after data processing of the monthly means of the sea levels, and a notice is taken of variations caused by active crustal upheavals during a seismic event, a local earthquake.  相似文献