首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   128篇
  免费   12篇
  国内免费   6篇
地球物理   23篇
地质学   94篇
海洋学   9篇
天文学   7篇
综合类   4篇
自然地理   9篇
  2022年   1篇
  2020年   1篇
  2019年   1篇
  2018年   2篇
  2017年   8篇
  2016年   2篇
  2015年   2篇
  2014年   3篇
  2013年   9篇
  2012年   3篇
  2011年   3篇
  2010年   3篇
  2009年   14篇
  2008年   6篇
  2007年   16篇
  2006年   13篇
  2005年   22篇
  2004年   6篇
  2003年   4篇
  2002年   3篇
  2000年   7篇
  1999年   3篇
  1998年   3篇
  1997年   1篇
  1994年   3篇
  1993年   2篇
  1991年   1篇
  1989年   1篇
  1987年   1篇
  1979年   2篇
排序方式: 共有146条查询结果,搜索用时 15 毫秒
101.
A large-scale transfer zone subdivides the northern parts of the Upper Rhine Graben into a northern and a southern sub-basin. These sub-basins display the geometry of asymmetric half-grabens with opposing tilt directions. The transfer zone connects the western master fault of the northern half-graben with the eastern master fault of the southern half-graben. In the northern Upper Rhine Graben early syn-rift sedimentation (Late Priabonian to Late Rupelian) was controlled by the tectonically induced subsidence of these half-grabens (autogenetic), as well as by regional third-order sea level variations (allogenetic). Within the graben, lateral changes in subsidence rates (in dip and strike direction of fault blocks) controlled the development of accommodation space and thus, sediment thickness and facies. Furthermore, a low-displacement segment along the western border fault acted as a sediment entry point. Tectonics controlled the distribution of early syn-rift deposits and the palaeogeography of the northern Upper Rhine Graben.  相似文献   
102.
The Rhine Rift System (RRS) forms part of the European Cenozoic Rift System (ECRIS) and transects the Variscan Orogen, Permo-Carboniferous troughs and Late Permian to Mesozoic thermal sag basins. Crustal and lithospheric thicknesses range in the RRS area between 24–36 km and 50–120 km, respectively. We discuss processes controlling the transformation of the orogenically destabilised Variscan lithosphere into an end-Mesozoic stabilised cratonic lithosphere, as well as its renewed destabilisation during the Cenozoic development of ECRIS. By end-Westphalian times, the major sutures of the Variscan Orogen were associated with 45–60 km deep crustal roots. During the Stephanian-Early Permian, regional exhumation of the Variscides was controlled by their wrench deformation, detachment of subducted lithospheric slabs, asthenospheric upwelling and thermal thinning of the mantle-lithosphere. By late Early Permian times, when asthenospheric temperatures returned to ambient levels, lithospheric thicknesses ranged between 40 km and 80 km, whilst the thickness of the crust was reduced to 28–35 km in response to its regional erosional and local tectonic unroofing and the interaction of mantle-derived melts with its basal parts. Re-equilibration of the lithosphere-asthenosphere system governed the subsidence of Late Permian-Mesozoic thermal sag basins that covered much of the RRS area. By end-Cretaceous times, lithospheric thicknesses had increased to 100–120 km. Paleocene mantle plumes caused renewed thermal weakening of the lithosphere. Starting in the late Eocene, ECRIS evolved in the Pyrenean and Alpine foreland by passive rifting under a collision-related north-directed compressional stress field. Following end-Oligocene consolidation of the Pyrenees, west- and northwest-directed stresses originating in the Alps controlled further development of ECRIS. The RRS remained active until the Present, whilst the southern branch of ECRIS aborted in the early Miocene. Extensional strain across ECRIS amounts to some 7 km. Plume-related thermal thinning of the lithosphere underlies uplift of the Rhenish Massif and Massif Central. Lithospheric folding controlled uplift of the Vosges-Black Forest Arch.  相似文献   
103.
The southern end of the Upper Rhine Graben (URG) is formed by a major continental transfer zone, which was localised by the reactivation of ENE-oriented basement faults of Late Palaeozoic origin. A combination of subcrop data (derived from exploration wells and reflection seismic lines) and palaeostress analysis provided new constraints on the timing and kinematics of interacting basement faults. Rifting in the southern URG began in the Upper Priabonian under regional WNW–ESE-directed extension, oriented roughly perpendicular to the graben axis. In the study area, this led to the formation of NNE-trending half-grabens. Simultaneously, ENE-trending basement faults, situated in the area of the future Rhine-Bresse Transfer Zone (RBTZ), were reactivated in a sinistrally transtensive mode. In the sedimentary cover the strike-slip component was accommodated by the development of en-échelon aligned extensional flexures. Flexuring and interference between the differently oriented basement faults imposed additional, but locally confined extension in the sedimentary cover, which deviated by as much as 90° from the regional WNW–ESE extension. The interference of regional and local stresses led to a regime approaching radial extension at the intersection between the URG and RBTZ.  相似文献   
104.
吉林省伊通地堑莫里青断陷水下扇沉积特征   总被引:9,自引:1,他引:9       下载免费PDF全文
伊通地堑位于吉林省中部,属佳-伊地堑的南段,是郯庐断裂带的北延部分,其西北缘为主控断裂,而东南缘为补偿极性断层。主控深大断裂和狭长的盆地分布使得该地堑的构造和沉积比较复杂,发育有多个小的断陷盆地。莫里青断陷是其中的一个主要含油气二级断陷盆地,其沉积盖层主要为古近系,为扇三角洲沉积体系和湖泊水下扇沉积体系,油气主要分布在双阳组不同的沉积体系中。本文重点描述了水下扇在岩芯上、测井曲线上、地震剖面上的特征。水下扇和扇三角洲在岩相组合、测井曲线特征和地震反射结构上均有较大的区别。水下扇的内扇、中扇和外扇随着时间的变化在平面上分布有很大变化,而西北边缘的扇三角洲一直保持不变。本区水下扇的形成与构造、物源和湖平面变化等因素有关。控盆断裂的长期活动使得在双二段时期发育大量的水下扇,而物源供给规模决定着水下扇的时空分布形态,直接物源形成的扇体规模较大,间接物源形成的扇体较小。  相似文献   
105.
In this paper, we investigate normal fault patterns produced by the sliding motion along a gently dipping normal fault by using analogue model tests and numerical modeling. The motivation for this study was offered by microseismic test data that indicate the existence of an active low-angle shear zone at a depth of 9–11 km in the extensional region of high seismic activity of the Gulf of Corinth (Greece). Both modeling techniques seem to support the hypothesis that the system of high-angle normal faults that are responsible for the final asymmetrical graben formation initiate at the tip of the active basal detachment nearest to the free surface. The normal faults propagate upwards with progressive sliding of the inclined basal plane, resulting in a first phase of symmetrical graben configuration that is delimited by a main synthetic fault and an antithetic fault forming a Rankine zone. Subsequent sliding on the inclined base induces a family of secondary antithetic normal faults, which are responsible for the asymmetry of the failure pattern and the diffusive character of deformation in that area. Shear deformation is more intense and localized along the synthetic normal fault than along the antithetic faults. Elaboration on the analogue test results has led to the phenomenological relations among four main parameters that describe the geometry of grabens, namely, (i) the width and (ii) the maximum subsidence of the graben, (iii) the dip angles of the conjugate normal faults, and (iv) the amount of sliding along the low-angle normal fault. However, analogue models do not produce the system of synthetic faults that is observed in the Gulf of Corinth. The effects of both friction angle variation along the detachment base and of the constitutive behavior of the model material on the configuration of the final structural pattern were also studied with a series of numerical continuum models. It was found that (a) the fault pattern of the Gulf of Corinth may be reproduced with either a strain-softening material with low elastic modulus or a constant strength material, and (b) two consecutive grabens, such as those of Gulfs of Corinth and Evia, may also be reproduced by an appropriate combination of variation of dip and frictional properties along the hypothesized detachment zone.  相似文献   
106.
In this study a 2D basin model has been built along a transect crossing the Horn Graben in WNW-ESE direction. The aim of the investigation was to improve the understanding of the thermal evolution of the basin and its influence on possible petroleum systems. The 2D model of the subsurface is based on one seismic line and data from two exploration wells. Both wells TD’ed in Triassic sediments. The updoming of the Ringkøbing-Fyn High began during Late Carboniferous–Early Permian. At the end of the Permian the Horn Graben became active due to regional extension. The subsequent sedimentation history from Triassic to date is well recorded by well reports. A matter of debate has been whether or not significant amounts of Pre-Permian sediments exist in this area of the North Sea. Since organic material rich Paleozoic sediments serve as source rocks in widespread areas of North Germany and the southern North Sea it would be of great importance to know whether the same deposits exist in the Horn Graben. Nielsen et al. (Bull Geol Soc Denmark Copenhagen 45:1–10, 1998) introduced a model, which shows Paleozoic sediments covering the basement at a maximum depth of 6.5 km. Assuming, Paleozoic sediments are underlying the Permian salt deposits there should be an active petroleum system present. The 2D model includes the Paleozoic source rock and tries to explain why two exploration wells have not found petroleum.  相似文献   
107.
In this study, we use contrasting zircon fission track age signatures of Alpine detritus and detritus derived from the Variscan realm to trace sediment pathways in Central Europe. Our data show that the Molasse Basin was connected with the Rhine Graben Sea during the Mid-Oligocene, thus joining the North Sea to the Paratethys. Within the Rhine Graben Sea, fairly strong south–north directed currents existed, transporting sand-sized Alpine detritus nearly 300 km towards the north. A connection between the Rhône-Bresse Graben and the Rhine Graben and/or the French Molasse Basin and the Swiss Molasse Basin, by contrast, is not supported by the fission track data. This may be explained by the existence of submarine rises that hampered the transport of sand-sized sediment towards the north/northeast.  相似文献   
108.
The Jiloca basin is a NNW–SSE trending, Neogene-Quaternary graben in NE Spain, bounded by normal faults with measurable hectometre-scale throws. Its overall trend truncates previous NW–SE folds. The sedimentary infilling includes Neogene and Quaternary deposits, exceeding 80 m in thickness. The stratigraphical and structural setting controls hydrogeology of the basin. Neogene marls constitute an aquiclude that separates a main Jurassic karstic, confined aquifer from a shallow, unconfined Plio-Quaternary aquifer. The Jurassic aquifer is laterally compartmented by impervious Upper Triassic anticline cores, though its piezometric surface usually lies 30–60 m higher than the Mesozoic-Neogene boundary. The geological, and specifically the hydrogeological features are not significantly compatible with a previously published hypothesis that considers the Jiloca depression as a polje (in which the final topography is the result of suballuvial karstic corrosion) for three reasons. First, the hypothetical corrosion front shows neither a specific relationship with the epiphreatic zone, nor control by the local presence of impervious Triassic rocks. Second, chemistry of groundwater at the underlying Jurassic aquifer would not allow limestone dissolution at rates necessary for producing the supposed erosion deepening of 300 m since the late Pliocene. Finally, no evidence of swallow holes or ponors has been found.  相似文献   
109.
王剑  徐翔军  陈秀艳  李本才  王伟涛 《世界地质》2007,26(2):240-244,253
伊通地堑岔路河断陷南段,在地堑西北缘断层及二号断层(F2)的制约下,主要分为梁家构造带和新安堡凹陷两个二级构造单元。根据三维地震资料进行系统的构造解析认为,该区可划分为滚动背斜带、断块隆起带和走滑断陷带三个构造带。该区沉积相类型及其展布规律主要受控于东南缘断层、西北缘断层及F2断层的构造活动。受不同的构造-沉积特征制约,形成西北缘边界断层下的断层-岩性油气藏、中央隆起带断块式油气藏、F2断层控制的构造-岩性复合油气藏。  相似文献   
110.
Episodic and localized illite mineralization is documented in the hydrothermally altered Soultz-sous-Forêts granite (Upper Rhine Graben, France). Separated grain-size fractions of altered granite and argillite vein samples contain mixtures of 2M1 and 1M trans-vacant illite varieties. The platy pseudohexagonal 2M1 illite phases dominate the vein fillings, whereas the 1M illite occurs largely as a fibrous pore-filling variety, which is particularly abundant in the granite matrix. Multiple phases of fluid injections into the granite body have resulted in different illite assemblages, each sample containing a mixture of polytype generations formed during different crystal growth events. On the basis of mineralogical and K–Ar isotopic constraints, the ages of these vein-mineralizing events are determined by plotting the K–Ar values of the various grain-size fractions against polytype abundance and the fitted volume-weighted crystallite thickness distributions. The results suggest a Permian age for the formation of the studied argillite veins, characterized by successive injections of hydrothermal fluids. Secondary episodes of illite crystallization occurred during Jurassic and Cretaceous (or even younger times) in both the veins and the granite matrix. There are indications that the polytype structure and composition of illite were strongly influenced by variations in fluid chemistry and the degree of fluid–rock interaction as the granite was progressively sealed during post-Variscan, episodic hydrothermal activity.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号