共查询到20条相似文献，搜索用时 156 毫秒
1.
松潘地块若尔盖盆地与西秦岭造山带岩石圈尺度的构造关系——深地震反射剖面探测成果 总被引：17，自引：2，他引：17
若尔盖盆地和西秦岭造山带作为青藏高原东北缘典型的新生代盆山构造,其接合部位的岩石圈结构及其深部构造关系为青藏高原东北缘板块碰撞的深部过程等研究奠定基础。横过盆山结合部位的深地震反射剖面长约63km,记录时间30s(TWT),探测深度超过莫霍面深达岩石圈地幔。该剖面首次揭露出青藏高原东北缘的盆山结合部位地壳和上地幔盖层的结构,发现了若尔盖盆地和西秦岭造山带下地壳以北倾为主的强反射特征,这种北倾的反射特征提供了若尔盖盆地俯冲到西秦岭造山带之下,而西秦岭造山带逆冲推覆到若尔盖盆地之上的地震学证据,初步揭示出若尔盖盆地和西秦岭造山带在挤压构造体系下形成的岩石圈尺度的构造关系,近于平坦的Moho反射特征反映两者在造山后期又经历了强烈的伸展作用。 相似文献
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松潘地块与西秦岭造山带下地壳的性质和关系——深地震反射剖面的揭露 总被引：28，自引：1，他引：28
松潘地块位于青藏高原的东缘，处于中国大陆东西向构造与南北向构造的结合部位，特殊的构造环境使其长期控制并影响着中国大陆的形成与演化。探测松潘地块的岩石圈细结构，揭示其与东昆仑-西秦岭造山带的关系，既可为研究青藏高原东北缘板块碰撞的深部过程奠定基础，同时又关联着松潘地块的油气远景评价。2004年完成了第一条横过松潘地块北缘若尔盖盆地和西秦岭造山带的长约257km的深地震反射剖面，首次揭露出若尔盖盆地和西秦岭造山带岩石圈的细结构。发现若尔盖盆地和西秦岭造山带同属统一的稳定的大陆地块，并且下地壳均以北倾的强反射为主要特征。这种北倾的反射为松潘地块向西秦岭下地壳俯冲提供了地震学证据。近于平坦的Moho反射特征反映出西秦岭造山带在造山后又经历了强烈的伸展作用。 相似文献
3.
东昆仑造山带中地壳存在古洋壳俯冲的深反射地震证据 总被引：1，自引：0，他引：1
INDEPTH Ⅳ深反射地震测线横跨可可西里-巴颜喀拉地块和东昆仑-柴达木地块,为揭示青藏高原东昆仑造山带深部构造提供了直接地球物理证据。针对地表和地下"双复杂"地质构造条件,地震数据处理中通过剩余折射波静校正技术、异常振幅噪声衰减技术和CRS优化叠加技术,获得了较高信噪比的地震反射叠加剖面。INDEPTH Ⅳ深反射地震剖面揭示,在东昆仑造山带岩石圈上、下地壳之间存在不连续的古洋壳反射同相轴,该反射界面应属古特提斯域松潘-甘孜洋壳向北俯冲遗迹,不连续特征反映中生代东昆仑-柴达木地块南缘属于被动大陆边缘碰撞带。利用INDEPTH Ⅳ深反射地震单炮、速度和叠加剖面等成果,综合解译数据,提出东昆仑造山带隆升过程的另一种模式,以助于深化东昆仑造山模式认识。 相似文献
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西秦岭造山带的演化、构造格局和性质 总被引：59，自引：6，他引：53
简要论述了西秦岭造山带显生宙以来的构造演化和格局,讨论了西秦岭造山带的性质。西秦岭造山带自800Ma左右以来,经历了超大陆裂解、洋陆演化、碰撞造山、板内伸展和陆内叠覆造山后才形成现今的西秦岭造山带。在不同的构造演化阶段,西秦岭有着完全不同的构造体制和格局。在洋陆演化阶段属板块构造体制,以多陆块洋为特征的洋陆格局;在板内伸展阶段属板内裂谷和裂陷盆地体制,以板内伸展盆地体系为特征的海陆格局;在陆内叠覆造山阶段属陆内盆山体制和陆内盆山格局。西秦岭造山带是一个“碰撞—陆内型”复合造山带。 相似文献
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西秦岭造山带位于青藏高原的东北缘,其岩石圈结构与变化记录着高原向东北发展演化的深部过程信息。西秦岭造山带也是中国资源开发的远景区,特别是随着全球石油的紧缺,我国石油地质界加快了新区勘探,西秦岭造山带与其两侧盆地被列为中国油气勘探评价值得重视和重新认识的战略选区之一。在野外观测的基础上,对跨越西秦岭和位于南祁连的临夏盆地的深地震反射剖面沿线的重要地质体进行了系统采样,开展了锆石U-Pb地质年代学、全岩元素和同位素（Sr和Nd）组成的测试工作。西秦岭—临夏盆地深地震反射剖面沿线重要岩浆岩岩石地球化学测试数据集中共包含3个数据表,分别为合作北部西秦岭造山带和临夏盆地内岩浆岩的锆石LC-MC-ICP-MS定年数据（共计7个测试样品、145个测试点,测试精度为（2σ）均为2%）、合作北部西秦岭造山带和临夏盆地内岩浆岩的主量元素和微量元素特征（共计33个测试样品,每个样品有69个测试项,含量大于10×10-6的元素的测试精度为5%,而小于10×10-6的元素精度为10%）、合作北部西秦岭造山带和临夏盆地内岩浆岩的Sr和Nd同位素特征（共计27个测试样品,Sr和Nd同位素的测试精度分别为±0.000010（n=18）,和±0.000011（n=18））。这些数据为厘定不同岩浆岩的形成年代和地球化学性质,从而更好地解译地震反射剖面揭示的深部地质构造所代表的构造意义。 相似文献
7.
静校正是深地震反射资料处理的关键技术之一,深反射剖面通常跨越多种不同的地质构造单元,地震地质条件复杂且变化较大,单一的静校正方法通常不能很好地解决深反射的静校正问题,针对兴蒙造山带西南段深反射地震数据进行静校正测试,最终选取多种静校正方法组合静校正技术,即针对不同地质条件分别应用折射和层析相结合来解决静校正问题。对于剩余静校正,采用模拟退火法解决,较好地解决了研究区的静校正问题,为资料后续处理提供借鉴。 相似文献
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四川叠合盆地盆山耦合特征分析 总被引：3，自引：5，他引：3
四川叠合盆地三面环山,自东而西夹持于江南、秦岭与龙门山三大山系之间,位于古亚洲、环太平洋与特提斯三大构造域的结合部位;中生代以来,先后经历了海盆、煤盆、陆相广盆、残盆四个盆地世代;盆地沉积充填过程可概括为前陆、坳陷、再生前陆三种基本样式。系统的山盆构造样式及运动学、沉积充填过程分析结果表明盆地周缘造山带造山活动期与盆内古隆起发育期时间耦合;盆地周缘造山带造山活动期与盆地沉积环境转换期时间耦合;盆地周缘造山带构造轴线走向基本保持与盆内山前坳陷或前陆褶冲带构造轴线走向相耦合;盆地周缘造山带不同时期形成的褶冲构造轴线走向基本保持与其同期盆内产生的沉积或沉降中心构造轴线走向相耦合。 相似文献
9.
黔西某煤矿受区域性地质构造控制,矿井地貌属高原低山丘陵地貌,最大相对高差为319．2m。该区采用可控震源和炸药震源激发,原始资料信噪低,静校正问题严重。在资料处理过程中,主要采取了折射静校正、地表一致性振幅补偿技术、反褶积、三维剩余静校正与高精度速度分析、DMO叠加、随机噪音衰减、三维一步法偏移等处理措施,很好地克服了地形变化大、资料信噪比较低、野外静校正效果不明显、大倾角反射成像差、层速度突变等难题,最终处理的剖面归位准确,目的层连续性较好,达到了“三高”处理目的。 相似文献
10.
川东北-大巴山盆山体系岩石圈结构及浅深变形耦合 总被引：1，自引：0，他引：1
近年来,盆山体系研究已经成为大陆动力学的热点和前沿领域之一。为了进一步理解大巴山前陆的构造演化,解决该区油气勘探的关键问题,中国地质科学院与中国石化南方公司合作,2007年完成了一条300km长的深地震反射剖面。基于深地震反射剖面提供的岩石圈结构的几何图式和深地震测深剖面提供的速度数据,作者分析了川东北-大巴山盆山体系的岩石圈结构特征,探讨了变形样式与岩石圈结构的关系,提出了对大巴山造山带形成的新认识。川东北-大巴山盆山体系继承了扬子克拉通基底。较大的岩石圈厚度和强度,导致扬子克拉通在与华北克拉通拼合后的陆内造山过程中, 将其收缩变形集中在其顶部而不是中下地壳,区域性的拆离层使盖层和基底解耦,结晶地壳保持弹性只出现大尺度的挠曲几乎没有横向缩短,故大巴山造山带表现为"薄皮"、"无根"的特征。大巴山造山带的席卷深度和变形样式主要受区域性的深部滑脱面控制,该滑脱面发育于寒武系底部泥岩层内,由TWT 4 .0s反射所指示。沿该滑脱面,城口断裂将南秦岭震旦系和古生界地层逆冲到浅表并向南西推覆60km叠置于四川盆地中-古生界地层之上;且镇巴断裂和城口断裂均收敛于该滑脱层,其下伏的变质岩层基本未卷入变形。 相似文献
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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
14.
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
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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
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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