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1.
怀安盆地位于河北省张家口,是晋冀蒙盆岭构造区的活动构造盆地之一,在其北缘发育了控制盆地的怀安盆地北缘断裂。为了研究断裂的活动性,在断裂中段开挖了3个探槽,TC-1位于一条冲沟的一级洪积扇上,TC-2位于二级洪积扇上,TC-3位于另一条冲沟的一级洪积扇上。TC-1揭示断裂没有断错厚度约12m的覆盖层;TC-2揭示出由多条次级断层组成的断裂,断裂断错了大部分层位,且位错量随深度加大;TC-3剖面特征与TC-2相似。通过对探槽剖面进行详细的分析、测绘、描述和取样测年,得到了有关断裂的活动性的参数。分析表明,怀安盆地北缘断裂中段的最新活动时代为晚更新世晚期,晚更新世的平均滑动速率为0.12mm/a。TC-2和TC-3探槽显示断裂曾有过多次活动,并可识别出至少3次地表破裂型的古地震事件,其中最后2次分别发生于距今约40 000 a和距今约28 000 a,平均同震垂直位移为1.3 m,断裂的平均地震重复间隔约为11 ka。断裂具有发生7级地震的能力,末次地表破裂型地震的离逝时间已超过20 ka,对其危险性应予以重视。 相似文献
2.
银川盆地新生代以来主要沿其边界断裂发生多期断陷活动,其边界断裂运动学特征记录了盆地的形成演化历史。基于其边界断裂滑动矢量的详细测量与分析,结合区域构造、盆地内沉积序列以及叠加变形分析,提出银川盆地新生代主要受NWSE向伸展、NESW向伸展与NESW向挤压3期构造应力场控制。结合区域构造演化与相关年代学数据,银川盆地新生代以来主要经历初始断陷、持续断陷与拉分断陷等3期构造演化,始新世-上新世受NWSE向伸展作用控制,银川盆地两侧主边界断裂发生正倾滑活动,导致盆地发生强烈断陷活动,充填了始新世-上新世红色砂岩、砾岩;更新世期间,古构造应力场转变为NESW向伸展,其主边界断裂以左行斜张活动,银川盆地持续断陷沉降;晚更新世晚期(?)以来,在NESW向挤压作用控制下,银川盆地主边界断裂发生强烈右行走滑兼正断活动,盆地受断裂剪切拉张活动,发生拉分断陷沉积。 相似文献
3.
祁连山北缘—河西走廊西段晚新生代逆冲推覆断裂发育模式 总被引：1，自引：0，他引：1
祁连山北缘—河西走廊西段地处青藏高原东北缘,是我国新构造活动最强烈的地区之一。通过野外对研究区主要活动断裂的调查研究、结合年代学测试和综合分析,认为祁连山北缘—河西走廊西段地区的旱峡—大黄沟断裂、玉门断裂、新民堡断裂和阴洼山断裂都是晚更新世至全新世活动断裂。旱峡—大黄沟断裂形成于中新世晚期,一直活动至今;玉门断裂形成于上新世早期,在距今7.6ka左右和3.2ka左右发生过2次强烈的新构造活动(古地震),也是2002年玉门地震的发震断裂;阴洼山断裂形成于上新世晚期(3.0Ma左右),在距今19.9～21.0ka、8.6～10.0ka、4.1～5.0ka发生过3次强烈的新构造活动,也可能是1785年惠民堡(现新民堡)地震的发震断裂;但是位于近盆地中心的新民堡断裂形成时代明显晚的多,起始于中更新世晚期(0.17Ma左右),在距今28.3ka、4.4ka和1.2ka左右发生过强烈的3次新构造活动。在运动形式上,上述4条断裂均为自南南西向北北东的逆冲推覆。在变形性质上,新民堡断裂以非地震性的蠕滑为主,其他3条断裂主要为地震性的粘滑变形。在祁连山北缘—河西走廊西段的北北东剖面上,逆冲推覆断裂表现为前展-后展复合发育模式,即形成时代最新的是位于酒西盆地中心的新民堡断裂,在酒西盆地中心以南部分的剖面中断裂发育为前展式,由祁连山腹地向河西走廊盆地中心断裂形成时代越来越新,而酒西盆地中心以北部分的剖面中断裂发育为后展式,即从盆地中心到盆地北缘断裂形成时代越来越老。 相似文献
4.
玉门断裂全新世活动特征及其与玉门地震的关系 总被引：12，自引：0，他引：12
玉门断裂是祁连山北缘断裂带的组成部分,也属于酒西盆地南缘断裂带的一支,是酒西盆地内二级构造单元的边界。玉门断裂表现为强烈的逆冲推覆特征,并有不大的左行水平位移分量,次级断裂走滑方向与其走向有关;玉门断裂自早更新世以来一直活动,是现代地震断裂,也是玉门地震的发震断裂。 相似文献
5.
内蒙古河套盆地为受断裂控制形成的新生代断陷盆地,盆地中积水成湖,称河套古湖。晚更新世时期,河套古湖为继承性闭塞型断陷湖。上更新统主要为湖泊沉积体系,地层划分建组为上部东河村组、中部万水泉组、下部达拉特组。达拉特组在湖盆连续沉降条件及半深湖深湖中硫酸盐型、碳酸盐型湖水交替环境下沉积形成。万水泉组在湖盆沉降速率与沉积速率大体平衡条件及浅湖半深湖中半咸水湖环境下沉积形成。东河村组在湖盆沉降速率小于沉积速率条件下以及半咸水湖、局部时期为碳酸盐湖环境下的滨浅湖中沉积形成。晚更新世末期,河套古湖处于大湖水期,晋陕内蒙古交界处河流袭夺、河套盆地北侧山前断裂强烈活动和超强地震导致河套古湖湖水快速外泄,银川盆地、河套盆地、晋陕峡谷贯通而形成今日黄河河道。 相似文献
6.
祁连山北缘-河西走廊西段地处青藏高原东北缘,是我国新构造活动最强烈的地区之一。通过野外对研究区主要活动断裂的调查研究、结合年代学测试和综合分析,认为祁连山北缘-河西走廊西段地区的旱峡-大黄沟断裂、玉门断裂、新民堡断裂和阴洼山断裂都是晚更新世至全新世活动断裂。旱峡-大黄沟断裂形成于中新世晚期,一直活动至今;玉门断裂形成于上新世早期,在距今76 ka左右和32 ka左右发生过2次强烈的新构造活动(古地震),也是2002年玉门地震的发震断裂;阴洼山断裂形成于上新世晚期(30 Ma左右),在距今199～210 ka、86～100 ka、41～50 ka发生过3次强烈的新构造活动,也可能是1785年惠民堡(现新民堡)地震的发震断裂;但是位于近盆地中心的新民堡断裂形成时代明显晚的多,起始于中更新世晚期(017 Ma左右),在距今283 ka、44 ka和12 ka左右发生过强烈的3次新构造活动。在运动形式上,上述4条断裂均为自南南西向北北东的逆冲推覆。在变形性质上,新民堡断裂以非地震性的蠕滑为主,其他3条断裂主要为地震性的粘滑变形。在祁连山北缘-河西走廊西段的北北东剖面上,逆冲推覆断裂表现为前展 后展复合发育模式,即形成时代最新的是位于酒西盆地中心的新民堡断裂,在酒西盆地中心以南部分的剖面中断裂发育为前展式,由祁连山腹地向河西走廊盆地中心断裂形成时代越来越新,而酒西盆地中心以北部分的剖面中断裂发育为后展式,即从盆地中心到盆地北缘断裂形成时代越来越老。 相似文献
7.
F~(201)断裂位于黄河黑山峡大柳树坝址北1.9km,长8.5km,呈北80°西方向,南倾60°—80°,为左旋逆冲断层,段古老的东西向构造带成分。第四纪以来,断裂的活动具分属性,仅中段长2.0km的范围内见距今2.2×10~4a以来至1.1×10~4a左右有过三次活动,时间分别为距今2.2×10~4a左右,1.72—1.31×10~4a之间,1.1×10~4a左右。而东段仅见晚更新世早期活动,西段大部分隐伏于晚更新世中、晚期地层之下。根据工程地质评价标准,F~(201)断裂应为非活动断裂,至多为弱活动断裂。而这种活动很可能是受其北侧中卫—同心断裂带的影响所至,而不象是F~(201)断裂发生地震造成的。为了大坝的安全,不妨认为F~(201)断裂为发震断裂,评价出断裂发震对大坝的影响烈度不会达到其基本烈Ⅷ度度,地震形变带宽度远不会达到400m,不会对坝址造成毁坏。因此,在大柳树当地材料高坝按基本烈度Ⅷ度设防的条件下,F_(201)断裂不会对工程产生危害。 相似文献
8.
牛首山-罗山断裂带是青藏高原东北缘弧形断裂系最外缘断裂带,自南向北由固原断裂、罗山东麓断裂、牛首山断裂及三关口断裂组成。通过遥感解译、野外调查及探槽揭露等方法对牛首山断裂北段柳木高断裂第四纪几何学、运动学特征进行了研究,并通过断层截切地层关系及年代学测试,限定了该断裂第四纪演化过程及全新世的地震事件。研究结果表明,柳木高断裂上新世至晚更新世自南西向北东逆冲,晚更新世至全新世左行走滑逆冲,表现为正花状构造,而全新世则发生了正倾滑运动。全新世期间,1690±30 yr BP（公元320-415）之后发生了一次古地震事件,推测柳木高断裂可能是公元876年青铜峡南6.5级地震的发震断裂。柳木高断裂第四纪早期活动特征与固原断裂、罗山东麓断裂及牛首山断裂一致,是青藏高原北东向持续扩展引起的,而全新世的正倾滑运动可能与银川地堑的伸展作用有关。 相似文献
9.
10.
阿尔金活动断裂带的运动学和动力学特征 总被引：6，自引：0，他引：6
位于喜马拉雅碰撞带后陆的阿尔金活动断裂带,是自西向东逐步形成的左旋走滑断裂。早期以逆冲活动为主,晚期以走滑活动为主。距今0.35Ma(中更新世)以来,平均左旋走滑速率为4.9±0.4mm/a,平均水平错动量是垂直错动量的12.3倍。晚更新世晚期至全新世时期发生过5次古地震,平均复现期为800年左右。 相似文献
11.
东濮凹陷北部沙三中亚段广泛发育盐岩和烃源岩,这两个看似不能共存的物质却在这里互层共生。该时期研究区沉积特征为多盐韵律与多层烃源岩互层共生、连续沉积,单个盐韵律厚度从几米到十几米,烃源岩有机质丰度高、类型好。平面上,两者在湖盆沉积沉降中心共生;垂向上,高有机质丰度、好干酪根类型与高盐度地层具有较好的对应关系。因而成为恢复古气候和古环境的重要研究对象。通过岩石学、古生物学以及Sr/Ba、B/Ga、(V+Ni+Mn)、Fe/Mn、Sr/Cu、Mg/Ca、V/(V+Ni)、稀土元素含量和氯同位素等方法对凹陷北部沙三中亚段的沉积环境进行研究。结果表明,凹陷北部沙三中亚段为深水沉积的还原环境,古盐度较高,达到半咸水-咸水沉积;微量元素和孢粉化石特征表明研究区沙三中亚段为温暖潮湿的环境。 相似文献
12.
The Importance of the Precipitation and the Susceptibility of the Slopes for the Triggering of Landslides Along the Roads 总被引：3，自引：1，他引：2
Clemente Irigaray Francisco Lamas Rachid El Hamdouni Tomás Fernández José Chacón 《Natural Hazards》2000,21(1):65-81
In order to characterise the influence of the heavyrains on the observed landslides during the 1996–1997hydrological cycle, rainfall records for the last 100years are analysed from 104 stations in easternAndalusia. Regarding the amounts of rain recordedbetween October 1996 and March 1997 in the 104stations studied, 31 presented new all-time records;15 presented values that were 80–100% of thepre-1995 record; 49 stations, 80–50%; and 9stations, < 50%. A map has been devised of thesusceptibility of the materials through which thesouth-eastern Andalusian road network crosses,together with an inventory of the damage caused byinstability phenomena on banks and cuttings of theroad network during the winter of 1996–1997. Therelationships between the rainfall during the studyperiod, the damage caused to the road network and thesusceptibility of the materials affected are analysed.The results indicate that there is a clearcorrespondence between the rainfall recorded and thesusceptibility of the materials with the inventorieddamage. It is concluded that the widespread seriousdamage caused in early 1997 to the roads andsurrounding areas in the Alpujarra region and thecoast of the Province of Granada was mainly caused bythe extraordinarily heavy rains. However, considerablyless damage was observed where the susceptibility ofthe terrain is low, thus highlighting the extremeusefulness of terrain-susceptibility maps for riskprevention and territorial planning. 相似文献
13.
郯庐断裂南段研究进展与断裂性质讨论 总被引：13，自引：3，他引：13
据1：5万区域地质调查和专题研究资料，就郯庐断裂带是否南延与消失的原因，其与大别—苏鲁造山带交截形成的假位错效应，以及与中新生代沉积盆地形成演化的关系等作了新的阐述。在此基础上，讨论了郯庐断裂带是否为巨大的左行平移断层或转换断层。认为郯庐断裂带可能是在“古郯庐带”的基础上于早侏罗世重新活动、白垩纪强烈活动的地堑型枢纽断裂带。 相似文献
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15.
Guboglo M. N. 《GeoJournal》1980,4(1):53-58
International unity is becoming ever stronger in this country owing to an increasing similarity in the development of the cultural environment. This comprises the provision of all the country's republics with a sufficient number of schools, theatres, and other institutions and cultural information media in accordance with the needs of the population. An important part is played by the rise in ‘the general educational level, as well as the level of professional qualifications and skills. Among all the Soviet nations and nationalities, this rise being more rapid among formerly backward peoples. Prominent among the factors of internationalization is the progressive development of the nationalities’ cultural resources, while professional culture is being increasingly brought within the reach of the masses.The implementation of the nationalities policy promotes the all-round development of all Soviet nations and nationalities, their drawing together, the upsurge of the individual capabilities of every Soviet citizen. 相似文献
16.
某高速公路下伏煤矿采空区稳定性分析 总被引：10，自引：0，他引：10
在论述某高速公路下伏砦脖煤矿采空区地质、采矿和工程地质特征的基础上, 进行了稳定性数值模拟分析, 定性与定量地分析与评价了该煤矿采空区的地表变形特征及稳定性。研究结果表明: 该煤矿采空区的变形尚未完成, 对拟建的高速公路将产生很大的危害, 必须采取相应的工程治理措施。 相似文献
17.
Jiayu Rong Michael Melchin S. Henry Williams Tatyana N. Koren Jacques Verniers 《《幕》》2008,31(3):315-318
The Global Stratotype Section and Point （GSSP） for the base of the Silurian System was defined in 1985. Since that time, a number of researchers have suggested that this section has serious deficiencies for use as a GSSP. As a result, in 2000, the Subcommission on Silurian Stratigraphy （SSS） proposed undertaking a formal restu@ of this GSSP, which was subsequently approved by the International Commission of Stratigraphy （ICS）. The result of this restudy was the formal proposal that the current GSSP, at 1.6 m above the base of the Birkhill Shale, at Dob＇s Linn, Scotland, should be maintained as the same locality and stratigraphic level, but the bios- tratigraphical definition of the boundary should be revised. The previously defined, basal Silurian grapto- lite zone, the Parakidograptus acuminatus Zone, should be subdivided into a lower Akidograptus ascensus Zone and a higher E acuminatus Zone. The base of the A. ascensus Zone, marked by the first appearance of A. ascensus, should be regarded as the biostratigraphic mark for the base of the Silurian. This proposal has now been formally approved by the SSS and ICS, and ratified by International Union of Geological Sciences. This is the first GSSP to undergo formal restudy and redefini- tion, and the proposal also included a recommended procedure for restudy of GSSPs. 相似文献
18.
Dean S. Oliver 《Mathematical Geology》1998,30(7):911-933
In reservoir characterization, the covariance is often used to describe the spatial correlation and variation in rock properties or the uncertainty in rock properties. The inverse of the covariance, on the other hand, is seldom discussed in geostatistics. In this paper, I show that the inverse is required for simulation and estimation of Gaussian random fields, and that it can be identified with the differential operator in regularized inverse theory. Unfortunately, because the covariance matrix for parameters in reservoir models can be extremely large, calculation of the inverse can be a problem. In this paper, I discuss four methods of calculating the inverse of the covariance, two of which are analytical, and two of which are purely numerical. By taking advantage of the assumed stationarity of the covariance, none of the methods require inversion of the full covariance matrix. 相似文献
19.
Deviation of the major axis of the inertia ellipsoid of the Moon from the direction toward the Earth
B. P. Kondratyev 《Astronomy Reports》2017,61(8):709-714
It is known from observations that the center of mass of the Moon does not coincide with the geometric center of its figure, and the line connecting these two centers is not aligned with the direction toward the center of the Earth, instead deviating toward the Southeast. This stationary deviation of the axis of the inertia ellipsoid of the Moon to the South of the direction toward the Earth is analyzed. A system of five linear differential equations describing the physical libration of the Moon in latitude is considered, and these equations are derived using a new vector method taking into account perturbations from the Earth and partly from the Sun. The characteristic equation of this system is obtained, and all five oscillation frequencies are found. Special attention is paid to the fifth (zero) frequency, for which the solution of the latitude libration equations are stationary and represents a previously unknown additional motion of the rotational axis of theMoon in a cone with a small opening angle. In contrast to the astronomical precession of the Earth, the rotation of the angular-velocity vector is in the positive direction (counter-clockwise), with the period T 3 = 27.32 days. On this basis, this phenomenon has been named “quasi-precession.” This quasi-precession leads to a stationary inclination of the major axis of the inertia ellipsoid of theMoon to the South (for an observer on Earth), making it possible to explain one component of the observed deviation of the center of mass of the Moon from the direction toward the Earth. The opening angle of the quasiprecession cone is approximately 0.834″. 相似文献
20.
正Artemia cysts are an extremely important component of aquaculture diets.It is well established that the cultivation of fish and shellfish derive substantial health and growth advantages when Artemia are included in the diets of the 相似文献