The 2005 Heidelberg and Speyer earthquakes and their relationship to active tectonics in the central Upper Rhine Graben     

J. R. R. Ritter  M. Wagner  K.-P. Bonjer  B. Schmidt 《International Journal of Earth Sciences》2009,98(3):697-705

We determine the source parameters of three minor earthquakes in the Upper Rhine Graben (URG), a Cenozoic rift, using waveforms from permanent and temporary seismological stations. Two shallow thrust-faulting events (M _L = 2.4 and 1.5) occurred on the rift shoulder just south of Heidelberg in March 2005. They indicate a possible movement along the sediment–crystalline interface due to tectonic loading from the near-by Odenwald. In February 2005, an earthquake with a normal-faulting mechanism occurred north of Speyer. This event (M _L = 2.8) had an unusual depth of about 22 km and a similar deep normal-faulting event occurred there in 1972 (M _L = 3.2). Other lower crustal events without fault plane solutions are known from 1981 and 1983. At such a depth, inside the lower crust, ductile behaviour instead of brittle faulting is commonly assumed and used for geodynamic modelling. Based on the newly available fault plane solutions we can confirm the brittle, extensional regime in the upper and lower crust in the central to northern URG indicated in earlier studies.  相似文献   

Response of drainage systems to Neogene evolution of the Jura fold-thrust belt and Upper Rhine Graben   总被引：1，自引：0，他引：1  

Peter A. Ziegler  Marielle Fraefel 《Swiss Journal of Geoscience》2009,102(1):57-75

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海拉尔盆地乌尔逊凹陷中的三角形断块：演化及对油气的控制作用   总被引：2，自引：0，他引：2       下载免费PDF全文

陈均亮  蒋鸿亮  李宏伟  林春华 《地质科学》2009,44(2):657-668

在乌尔逊凹陷中部发育一个三角形断块,因边界断裂的同沉积活动而使断块沉陷深,沉积厚度大.晚期的构造反转使整个三角形断块向上冲断,尤以北界断裂的冲断活动表现强烈.三角形断块为各时期的沉积中心,控制着深湖相和湖底扇沉积的发育;烃源岩的类型也与三角形断块有关,块内为Ⅰ型和Ⅱ型干酪根,边部和外部为Ⅱ型和Ⅲ型十酪根.南屯组的有效烃源岩在乌尔逊断陷分布范围较大,主力烃源岩只局限于三角形断块内.晚期反转时北界断裂有利于构造圈闭的形成,反转断层也为油气的运移提供了通道.因此,三角形断块在生储盖层的发育和油气生成、运移与聚集的空间配置关系上可谓得天独厚,是最有利的油气聚集区.  相似文献   

Crude oil families in the Euphrates Graben (Syria)     

《Marine and Petroleum Geology》2017

The most petroliferous province in Syria is the Euphrates Graben system in the eastern part of the country. The source of the produced light and heavy oils has been a matter of debate from a petroleum geochemistry perspective as there are several possible source rock and just one proven source rock (R'mah formation). Based on gross composition and oil-oil correlation of biomarker and non-biomarker characteristics, three oil families have here been identified in the study area. Crude oils of Family 1 have been found to be generated from a marine and clay-rich source rock that is older than Jurassic in age based on age-related biomarker parameters (steranes and nordiacholestane ratios). Maturity-related parameters (aliphatic biomarkers and diamondoids) signal that the source of this oil family had a high maturation level. These features fit very well to the Tanf Formation (Abba Group) which is equivalent to Lower Silurian Hot Shales found elsewhere in the Middle East and North Africa. However, the Upper Cretaceous R'mah Formation and Shiranish Formation were found to be responsible for generating the majority of the crude oils studied (Family 2). Compositional and molecular differences between Families 2A and 2B were attributed to facies and subtle maturation variations. Geochemical oil-source rock correlations indicate that Family 2A was most likely sourced from the Shiranish Formation, while Family 2B was sourced from the R'mah Formation. Secondary alteration processes influenced bulk petroleum composition, most notably the depletion of light ends and the lowering of API gravity, particularly in the northwestern part of the graben.  相似文献   

北京地区小震精定位结果初步探讨     

钟世军  王治国  司政亚  孙海霞  岳晓媛  武敏捷 《中国地震》2022,38(3):513-525

利用双差重定位方法对北京地区(39.2°N～41.2°N,115.2°E～117.6°E)2008年10月至2020年3月期间共6463个地震事件进行重新定位,得到4776个高质量地震事件的空间位置分布。定位结果均方根走时残差显著降低,震源间的相对位置精度明显提高,地震活动的成丛性与活动断层之间的关系更加密切。根据重定位结果探讨了小震活动与活动断裂及深浅构造的关系,得到以下结论:夏垫断裂小震活动强烈,重定位后震中分布明显向断裂靠拢,呈现沿断裂走向延伸的NE向线状分布。结合人工剖面探测结果推测,该区域深度剖面上小震集中带10km深度附近较宽的丛集区主要是浅部铲形断裂活动所致,14～22km深度附近相对较窄近直立的小震丛集为深部断裂活动产生。怀—涿次级盆地北缘断裂现今小震活动活跃,该区域小震深度剖面揭示该断裂为倾向南东、上陡下缓的铲形断层。结合人工剖面探测结果,分析认为该区域深浅断裂共存和非均匀的地壳结构为中强地震发生的深部构造背景。平原区内部小震分布与第四纪断陷盆地和地层厚度分布存在较强的相关性,研究区域内部昌平—海淀小震集中区、顺义小震集中区、夏垫小震丛集区和廊坊小震丛集区分别位于马池口—沙河断陷盆地、顺义断陷盆地、大厂断陷盆地和固安—廊坊—永清断陷盆地。根据小震空间密集成带分布特征来推测未知断裂,推测怀柔南部山区小震集中区下方存在隐伏断层,宝坻至夏垫断裂段之间NW向的小震集中分布区下方存在一条走向NW或者NWW的隐伏断层。  相似文献   

Tectonic geomorphology of the northern Upper Rhine Graben, Germany   总被引：5，自引：2，他引：3  

Gwendolyn Peters  Ronald T. van Balen 《Global and Planetary Change》2007,58(1-4):310

This paper focuses on the northern Upper Rhine Graben (URG), which experienced low tectonic deformation and multiple climate changes during Quaternary times. Recently, human modifications have been high. The paper presents the results of a study into the effects of fault activity on the landscape evolution of the area. The study aims to detect active faults and to determine the last phase of tectonic activity. Information on the long-term tectonic activity is gained from the geological record (drainage system, sediment distributions, fluvial terraces, fault mapping). Previous studies are reviewed and supplemented with new data on tectonic activity. The compilation of all data is presented as a series of paleogeographic maps from Late Miocene to present. It is demonstrated that differential uplift of the western margin of the northern URG had significant impact on the drainage system, the formation of fluvial terraces and the landscape of the western graben shoulder. In a second part of the paper, the imprint of tectonics on the present-day landscape is investigated at the regional scale in order to determine the location of fault scarps and tectonically influenced parts of the drainage system. This study uses an integrated analysis of topography, drainage patterns and fault network. The comparison of features suggests a structural control by numerous NNE- and NNW-oriented intra-graben faults on the flow directions of streams in the Rhine Valley. Several scarps in the Rhine Valley are identified and interpreted to result from intra-graben faulting activity, which in turn controlled fluvial dissection. The third part of the paper presents quantitative measurements of the present-day landscape shape. Calculations of geomorphic indices are used to determine the balance between erosional and tectonic processes and to identify active fault segments. The mountain-front sinuosity and valley shape indices measured along the border faults and in the footwall area are used to determine the level of activity of the faults. Stream profiles of the western and eastern catchments of the River Rhine are investigated for gradient changes at the crossing of the border faults. The combined interpretation of geomorphic indices points to active border fault segments on both sides of the graben. Based on the integration of all results it is concluded that the tectonic morphology identified for the northern URG formed in response to long-term, low level tectonic processes. Due to a significant decrease in erosional and depositional activity during the last 15,000 years, the tectonic morphology has probably been preserved until present.  相似文献   

Does a detachment level exist beneath the Ceraunius Fossae? Insights from graben mapping and lost-area balancing analysis     

F. Borraccini  L. Lanci  F.C. Wezel 《Planetary and Space Science》2006,54(7):701-709

We took advantage of the close relationship between graben width and rheology of the involved materials (e.g., number, thickness and spacing of rheological layers, presence of mechanical discontinuities of different nature) and attempted to obtain information about the mechanical stratigraphy of the Ceraunius Fossae area (Northern Tharsis Region). The possible existence of detachment levels beneath the Ceraunius Fossae area were investigated using the lost-area balancing method and a topographic profile derived from Mars Orbiter Laser Altimeter (MOLA) data. Results suggest a marked difference in structural style between the western and eastern sectors of the study area, which is interpreted as a result of different mechanical stratigraphies. On the western sector the maximum depth reached by grabens is well localized within 1000 m from the topographic surface suggesting the existence of a detachment level, which we interpret as a weak horizon at the base of the Late Hesperian-Early Amazonian units. The ductile behaviour of this horizon could be favoured by the presence of volatile reservoir or ice. In the eastern sector of the profile (HNf and Hf units) the maximum depth reached by the grabens is scattered and does not support the existence of clearly defined detachment horizons suggesting that Noachian Fractured Rocks are mechanically homogeneous. A maximum depth, however, could be established.  相似文献   

The Denizli graben-horst system and the eastern limit of western Anatolian continental extension: basin fill,structure, deformational mode,throw amount and episodic evolutionary history,SW Turkey     

《Geodinamica Acta》2013,26(3-4):167-208

The Denizli graben-horst system (DGHS) is located at the eastern-southeastern converging tips of three well-identified major grabens, the Gediz, the Küçük Menderes and the Büyük Menderes grabens, in the west Anatolian extensional province. It forms a structural link between these grabens and the other three NE-NW-trending grabens—the Çivril, the Ac?göl and the Burdur grabens—comprising the western limb of the Isparta Angle. Therefore, the DGHS has a critical role in the evolutionary history of continental extension and its eastward continuation in southwestern Turkey, including western Anatolia, west-central Anatolia, and the Isparta Angle. The DGHS is a 7-28-km wide, 62-km long, actively growing and very young rift developed upon metamorphic rocks of both the Menderes Massif and the Lycian nappes, and their Oligocene-Lower Miocene cover sequence. It consists of one incipient major graben, one modern major graben, two sub-grabens and two intervening sub-horsts evolved on the four palaeotectonic blocks. Therefore, the DGHS displays different trends along its length, namely, NW, E-W, NE and again E-W.

The DGHS has evolved episodically rather than continuously. This is indicated by a series of evidence: (1) it contains two graben infills, the ancient graben infill and the modern graben infill, separated by an intervening angular unconformity; (2) the ancient graben infill consists of two Middle Miocene-Middle Pliocene sequences of 660 m thickness accumulated in a fluvio-lacustrine depositional setting under the control of first NNW-SSE- and later NNE-SSW-directed extension (first-stage extension), and deformed (folded and strike-slip faulted) by a NNE-SSW- to ENE-WSW-directed phase of compression in the latest Middle Pliocene, whereas the modern graben infill consists of 350-m thick, undeformed (except for local areas against the margin-bounding active faults), nearly flat-lying fanapron deposits and travertines of Plio-Quaternary age; (3) the ancient graben infill is confined not only to the interior of the graben but is also exposed well outside and farther away from the graben, whereas the modern graben infill is restricted to only the interior of the graben. These lines of evidence imply an episodic, two-stage extensional evolutionary history interrupted by an intervening compressional episode for the DGHS.

Both the southern and northern margin-bounding faults of the DGHS are oblique-slip normal faults with minor right- and/or left-lateral strike-slip components. They are mapped and classified into six categories, and named the Babada?, Honaz, A?a??da?dere, Küçükmal?da?, Pamukkale and Kaleköy fault zones, and composed of 0.5-36-km long fault segments linked by a number of relay ramps. Total throw amounts accumulated on both the northern and southern margin-bounding faults are 1,050 m and 2,080 m, respectively. In addition, the maximum width of the DGHS and the thickness of the crust beneath it are more or less same (~ 28 km). The total of these values indicate a vertical slip rate of 0.15-0.14 mm/year and averaging 7% extension for the asymmetrical DGHS.

The master faults of the Babada?, Honaz, Küçükmal?da?, Pamukkale and Kaleköy fault zones are still active and have a potential seismicity with magnitudes 6 or higher. This is indicated by both the historical (1703 and 1717 seismic events) to recent (1965, 1976, 2000 seismic events) earthquakes sourced from margin-bounding faults and some diagnostic morphotectonic features, such as deflected drainage system, degraded alluvial fans with apices adjacent to fault traces, back-tilting of fault-bounded blocks, and actively growing travertine occurrences. The kinematic analyses of main fault-slip-plane data, Upper Quaternary fissure ridges and focal-mechanism solutions of some destructive earthquakes clearly indicate that the current continental extension (second-stage extension) by normal faulting in the DGHS continues in a (mean) 026° to 034° (NNE-SSW) direction.

Detailed and recent field geological mapping, stratigraphy of the Miocene-Quaternary basins, palaeostress analysis of fault populations and main margin-bounding faults of these basins, extensional gashes to fissures, and focal-mechanism solutions of destructive earth-quakes that have occurred in last century strongly indicate that extension is not unidirectional and confined only to western Anatolia, but also continues farther east across the Isparta Angle and west-central Anatolia, up to the Salt Lake fault zone in the east and the inönü-Eski?ehir fault zone in the north-northeast. Therefore, the term “southwest Turkey extensional province” is proposed in lieu of the term “west Anatolian extensional province”.  相似文献   

Ar40-Ar39 dating of biotite and sanidine in tuffaceous sediments and related intrusive rocks: Implications for the Early Miocene evolution of the Gördes and Selendi basins,W Turkey     

《Geodinamica Acta》2013,26(3-4):239-253

The precise ages of the sedimentary successions within two prominent NE-SW-trending basins, the Gördes Basin and the Selendi Basin, are critical to an understanding of the Neogene evolutionary setting of western Turkey and associated calc-alkaline magmatism. Early radiometric dating was not always sufficiently precise to resolve alternative interpretations. During this study, high-precision Ar40-Ar39 radiometric ages were determined on single crystals of biotite and sanidine from silicic tuffs and associated intrusive rocks. Finegrained tuffaceous sediments near the top of the sedimentary succession in the Selendi Basin gave ages of 18.89 ± 0.58 Ma to 16.42 ± 0.09 Ma. Coarser-grained tuffaceous sediments near the top of the equivalent sedimentary succession in the Gördes Basin to the NW yielded ages of 18.78 ± 0.3 Ma to 17.04 ± 0.35 Ma. Associated intrusive rocks were dated at 20.86 ± 0.08 Ma to 17.62 ± 0.07 Ma. An andesitic body on the northern margin of the Gediz (Ala?ehir) Graben further south gave ages of 16.08 ± 10.91 to 14.65 ± 0.06 Ma.

Combined with published radiometric age data, these new results confirm an Early Miocene age for the clastic sedimentary fills of the Gördes and Selendi basins. The results from the Gediz Graben are consistent with its formation in Early Miocene time, earlier than the Late Miocene or Plio-Quaternary ages suggested in some interpretations.  相似文献   

An exceptional rocky shore preserved during Oligocene (Late Rupelian) transgression in the Upper Rhine Graben (Mainz Basin,Germany)     

Stephane Rousse  Philippe Duringer  Karl R. G. Stapf 《Geological Journal》2012,47(4):388-408

The Early Oligocene (Late Rupelian) Alzey Formation (Mainz Basin, Upper Rhine Graben, Germany) records the development of a rocky coast depositional system during transgression. The formation unconformably overlies Permian bedrock across a composite transgressive ravinement surface. Exposure of the surface shows a succession of subplanar bedrock terraces, separated by near‐vertical risers. Terraces show a broad staircase geometry and display wave‐erosional features (notches, sea stacks, furrows). Detailed sedimentological and palaeoecological investigations reveal prograding beachface and shoreface depositional units that overlie terraces and are adjacent to risers. Terraces are interpreted as wave‐cut platforms, backed by palaeocliffs. The staircase architecture records the episodic landward migration of palaeoshorelines onto palaeotopographic highs during the Early Oligocene. Stacking patterns of gravelly beach and shoreface associated units (facies tracts) indicate successive episodes of terrace cutting, beach development, drowning and shoreline backstepping during an overall relative sea‐level rise. The exceptional preservation of the stair‐cased rocky shore may be attributed to a highly jerky rising relative sea‐level, as the result of the conjugated effects of rift‐controlled tectonic subsidence and eustatic sea‐level oscillations. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献