塔里木盆地北部库车坳陷白垩系层序地层与体系域特征   总被引：10，自引：0，他引：10  

肖建新  林畅松  刘景颜 《地球学报》2002,23(5):453-458

结合露头和钻井资料对库车坳陷白垩系进行了层序地层划分，共分出1个一级层序、3个二级层序、8个三级层序，对其体系域的构成及其纵、横向变化特征进行了讨论。结果表明，沉积物主要来自北部的天山造山带；盆地及其充填层序的南北不对称性，反映了白垩纪库车坳陷的性质具有前陆盆地的特征。在苏善组的2个层位发现了厚度达10－20m的暗色泥岩，反映本区白垩纪的干热型气候曾间歇性出现过短暂的潮湿时期。  相似文献   

江西瑞昌1995年ML4.9级地震前后九江地震台倾斜固体潮汐变化分析     

赵爱平  吴敏 《华南地震》2002,22(4):79-84

通过月整点值数据文件和滑动值数据文件这两种数据处理形式。对九江台地倾斜资料进行调和分析计算。分析了M2潮汐因子与瑞昌ML4.9级地震的关系。认为存在震前短临异常或震后异常，并与趋势异常得到相互印证。  相似文献   

Earthquake—generating Structure Revealed by 1999 Sichuan mianzhu Earthquake Sequence with Ms=5.0     

Zhao Zhu  Wang Bilan  Long Sisheng 《中国地震研究》2002,16(2):147-154

Through the accurate determination of hypocenter location,the measurement of the main focal mechanism solutions and the analyses of time dependent processes for Sichuan Mianzhu earthquake sequence with Ms=5.0 occurred along the middle segment of Longmenshan fault zone on November 30,1999,the distribution of focal depth section,the stress relase and seismicity features are given to reveal the earthquake-geneating structure of the earthquake sequence.The obtained results show the activity features for this sequence as follows:(1) There is no obvious foreshock,the accumulated strain energy releases in nearly pulse way,fluctuation of the seismic activity level is not quite evident during the duration of the sequence,and the statistical relation between the large events and the small events is less compatible with the traditional G-R estimation;(2) The epicenters of the earthquake sequence are not distributed on the main Longmenshan piedmont faults emerging out ground,but near the hidden Longmenshan piedmont faults.The direction of epicenter distribution is not very coincident with the fault strikes.The microscopic epicenters are relatively far from the macroscopic epicenters,The focal depths range from 5km to 16km;(3) The fractures of focal fault plane with the NE strike appear out the strike-slip displacement with a few overthrust components under the major principal compressive stress of NNE direction.From these,we consider it should be paid more attentions to the underground hidden faults near the ground fault zone on a large scale for their generating earthquake risk.  相似文献   

Models of passive margin inversion: implications for the Rhenohercynian fold-and-thrust belt, Belgium and Germany     

Y Vanbrabant  J Braun 《Earth and Planetary Science Letters》2002,202(1):15-29

Positive tectonic inversion is related to the transmission of compressional stresses along a décollement into the foreland of an orogenic zone. This stress and strain concentration in regions remote from the main orogenic front is commonly related to the presence of pre-existing rheological heterogeneities such as normal syn-depositional faults. During inversion, these pre-existing normal faults are reactivated as reverse faults. Tectonic inversion in the Rhenohercynian fold-and-thrust belt during the Variscan Orogeny shows that inversion is likely synchronous with the onset of collision in the hinterland. Here, we present the results of a simplified thermo-mechanical model (STM) which allows one to study strain partitioning between two orogenic zones. We show that, if the two orogenic zones have the same mechanical properties, the viscosity of the décollement, which links them, controls the initial strain partitioning. During subsequent finite shortening, erosional processes determine the partitioning of strain rate. The presence of a weak structure in the inverted zone and of a low-viscosity décollement leads to initial strain concentration in the inverted track rather than in the collision zone and a progressive decrease in strain partitioning between the two orogenic zones. The STM results are in good agreement with results of a 2D finite-element model. We conclude that, in the western part of the Rhenohercynian Massif, simultaneous uplift and deformation within the Mid-German Crystalline Rise (the main collision zone) and the Ardenne Anticlinorium (the inverted zone) lead to interpreting this orogenic event as a case of vice tectonic rather than the propagation of a ‘wave of folding’ towards the Variscan front, as suggested by previous authors.  相似文献   

A 2-D hybrid technique to model the effect of topography on coseismic displacements. Application to the Umbria-Marche (central Italy) 1997 earthquake sequence     

Stefano Tinti  Alberto Armigliato 《Geophysical Journal International》2002,150(2):542-557

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皖西南地区南华纪—志留纪层序地层分析   总被引：1，自引：0，他引：1       下载免费PDF全文

吴跃东  江来利  储东如  吴维平  吴海权  汪德华 《沉积与特提斯地质》2003,23(1):45-52

在1：25万区域地质调查基础上，通过对宿松—东至地区南华纪-志留纪地层露头剖面研究，对其相应的沉积环境、沉积相进行了分析，并根据生物地层、岩石地层和年代地层等成果，将南华纪-志留纪地层划分为1个一级层序，5个二级层序和15个三级层序组。一级和二级层序在沉积相序上总的趋势表现为浅→深→浅的变化，且与海平面变化曲线相吻合；三级层序组海平面上升和下降往往受构造运动、海平面变化；冰川事件影响。  相似文献   

中扬子区寒武纪层序地层研究   总被引：2，自引：0，他引：2       下载免费PDF全文

周雁  陈洪德  王成善  金之钧  汤良杰  王正元  梁西文 《沉积与特提斯地质》2003,23(3):65-72

笔者建立了中扬子区寒武系层序地层格架，研究了中扬子区层序界面和体系域特点，分析了中扬子区层序样式的基本类型及其特征。共划分出2个二级层序、14个三级层序。寒武系下统划分了1个二级层序(SS3)、6个三级层序(SQ1—SQ6)，平均延时约5．0Ma；体系域颜色普遍较深，泥质含量较高，是一套良好的烃源岩。寒武系中上统划分出1个二级层序(SS4)、8个三级层序(SQ7—SQ14)，平均延时约2．9Ma；体系域颜色普遍较浅，云质含量较高，是一套良好的储集层。总体上H型样式为主，T型样式和TH型样式数量相当，反映寒武纪水体中等。二级层序体系域和三级层序体系域都表现出明显的南北向差异性。  相似文献   

湘西北慈利大庸地区上震旦统—下寒武统沉积特征及层序地层划分   总被引：1，自引：0，他引：1       下载免费PDF全文

李忠雄  王剑  段太忠  高永华 《沉积与特提斯地质》2003,23(4):27-33

通过对各类层序界面的识别，以沉积特征、副层序和体系域与结构转换面等层序分析，进行露头层序地层学研究，将湘西北慈利—大庸地区台缘斜坡相区上震旦统—下寒武统划分为11个Ⅲ级层序，其中上震旦统7个、下寒武统4个，主要是Ⅱ型层序。在区域层序地层对比、分析的基础上初步讨论了露头层序地层分析中存在的问题。  相似文献   

长江源各拉丹冬地区三叠纪结扎群沉积特征及层序地层研究   总被引：5，自引：0，他引：5  

牛志军  姚华舟  段其发  白云山  王建雄  卜建军  曾波夫 《华南地质与矿产》2003,(4):66-72

三叠纪结扎群分布于长江源各拉丹冬地区南北两侧，根据基本层序、沉积环境和层序界面特征，结扎群至少可划分出四个三级层序。沉积古地理格局显示出南浅北深的特点。南部靠近羌塘盆地中央隆起带，陆源物质供应丰富。北部雀莫错一带因远离中央隆起，陆源物质供应相对较少，以泥岩、灰岩为主，生物化石丰富，沉积环境以陆棚为主，在相对稳定的沉积水体中以双壳类、菊石类等生物群得以快速发展。  相似文献   

Late Caledonian Ductile Thrusting Deformation in the Central East Kunlun Belt, Qinghai, China and Its Significance: Evidence from Geochronology   总被引：5，自引：0，他引：5  

WANG Guocan  CHEN Nengsong  ZHU Yunhai  ZHANG Kexin Faculty of Earth Sciences  China University of Geosciences  Wuhan  Hubei  E-mail: wgcan@cug.edu.cn Ren Xifei  Liu Ruixun  Xie Guanglian 《《地质学报》英文版》2003,77(3)

A high-angle ductile thrusting deformation with top-to-the-north movement penetratively developed in the Proterozoic-Early Paleozoic metamorphic rocks along the Central East Kunlun belt. The deformed rocks suffered epidote-amphibolite facies metamorphism. On the basis of our previous study, we present more data in this paper to further support that the ducdle thrust deformation occurred in the later Caledonian and more detailed information about the deformation. A zircon U-Pb concordant age of 446±2.2 Ma of a deformed granodiorite in the ductile thrust zone was obtained and can be interpreted as the lower limit of the deformation. A syntectonically crystallized and also strongly deformed hornblende Ar/ Ar dating gives an Ar/Ar plateau age of 426.5±3.8 Ma, which represents the deformation age. A strongly orientated muscovite gives an Ar/Ar plateau age of 408±1.6Ma, representing the cooling age after the peak temperature, constraining the upper limit of the ductile thrust deformation. This ductile thru  相似文献