首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 437 毫秒
1.
准噶尔盆地南缘断裂带显微构造特征与活动时代   总被引:1,自引:0,他引:1  
对准噶尔盆地南缘霍尔果斯-玛纳斯-吐谷鲁逆断裂带中的断层泥和构造岩显微构造进行了研究,并对断裂带中的石膏、石英脉和断层泥进行了ESR测年。显微构造研究表明,断裂带至少经历了3期构造变形,断层泥和石英碎粒中既发育有线状擦痕、阶步等粘滑活动显微构造,也发育有剪切滑动、定向排列等蠕滑活动变形现象。ESR测年结果显示,霍尔果斯-玛纳斯-吐谷鲁逆断裂带形成于1.5Ma前,在0.4~1.0 Ma和0.08~0.12 Ma期间进行了二次再调整。断裂活动时间与青藏高原阶段性隆升的时间一致,说明准噶尔盆地南缘霍尔果斯-玛纳斯-吐谷鲁逆断裂带的形成与青藏高原的隆升过程密切相关。   相似文献   

2.
根据采集的天然断层泥样品 ,对准噶尔盆地南缘霍尔果斯和吐谷鲁逆断裂带中断层泥进行了显微构造、显微形貌和分形研究。研究结果表明 ,断层泥至少存在三期变形 ;同时断层泥和石英碎粒中既发育有线状擦痕、阶步等典型的粘滑活动显微构造 ,也发育有剪切滑动、定向排列等典型的蠕滑活动变形现象 ,说明了断裂活动的长期性和复杂性。断层泥的分形研究表明 ,霍尔果斯和吐谷鲁断裂带断层泥分维值分别在 2 .17~ 2 .6 3和 2 .76~ 2 .89变化 ,分维值与断层运动方式粘滑或蠕滑不存在因果关系。因此 ,断层泥分维值能否作为判别断裂活动方式值得进一步研究。  相似文献   

3.
乌鲁木齐山前坳陷逆断裂-褶皱带及其形成机制   总被引:66,自引:9,他引:57  
乌鲁木齐山前坳陷位于天山新生代再生造山带北侧,南以准噶尔南缘断裂与天山相隔,内部发育了几排逆断裂 背斜带,每一排构造带又由多个逆断裂 背斜组成。最南的齐古逆断裂 背斜带形成于中生代末,其北的玛纳斯逆断裂背斜带包含霍尔果斯、玛纳斯和吐谷鲁逆断裂背斜,形成于上新世末、早更新世初,受上、下2 个滑脱面和断坡的控制,形成上、下2 个背斜。再向北的独山子逆断裂背斜带由独山子、哈拉安德和安集海逆断裂背斜组成,形成于早、中更新世之间,主逆断裂向下在8 ~9 km 深处的侏罗系中变为近水平滑脱面。此外,在独山子和吐谷鲁背斜的西北和东北还分别发育有正在形成之中的西湖和呼图壁隆起。研究了这些逆断裂 背斜带的地表和深部的构造特征、二维和三维几何学及运动学后指出,它们是在天山向准噶尔盆地扩展过程中发育于近水平滑脱面和不同断坡上的断展褶皱,独山子和安集海逆断裂 背斜的水平缩短量分别为2 900 ,1 350 m ,缩短速率分别为397 ,187 m m/ a。霍尔果斯、玛纳斯、吐谷鲁逆断裂 背斜的水平缩短量分别为5 900 ,6 500 ,6 000 m ,相应的缩短速率分别为202,223 ,206 m m/a,准噶尔南缘断裂和乌鲁木齐山前坳陷第四纪?  相似文献   

4.
准噶尔盆地南缘前陆冲断带形成时间的初步厘定   总被引:8,自引:0,他引:8  
一般认为生长地层的时代就是构造形成的时代(Suppe等,1992;Shaw 等,1994).准噶尔盆地南缘前陆冲断带发育地表可见的三排构造带:以齐古-喀拉扎背斜-清水河构造为主的第一排构造、以霍尔果斯-玛纳斯-吐谷鲁背斜为主的第二排构造、以独山子-安集海背斜-呼图壁背斜为主的第三排构造,卷入三排构造的地层有侏罗系、白垩系、第三系和第四系,形成了现今复杂的地貌地形和地层分布,三排构造带的形成时间对油气评价和油气勘探意义重大.  相似文献   

5.
祁连山各个山前盆地内发育了大量断裂和褶皱,是青藏高原向北扩展的重要表现形式。对这些断层和褶皱的研究有助于探讨青藏高原向北扩展和隆升的机制问题。酒西盆地是位于祁连山最西端的山前坳陷盆地,其内部正在发育最新生的白杨河逆断裂-褶皱带。本文通过对白南断裂-白杨河背斜的地质调查、阶地测量以及探槽开挖工作,对酒西盆地内部最新生的白杨河逆断裂-褶皱得到了几点认识:①白杨河逆断裂-褶皱是酒西盆地内新生的逆断裂-褶皱,是酒西盆地边界断层无法完全吸收青藏高原向北扩展的变形量所产生的次级构造。②白南断裂-白杨河背斜符合断层相关褶皱中的断弯褶皱模型,并存在膝折带迁移的现象。③白杨河背斜的起始隆升时间在中更新世后期,即距今300ka左右,平均隆升速率约0.21mm/a;构造强度有逐渐增大的趋势,全新世以来隆升速率约0.36~0.5mm/a。④白南断裂是全新世活动断裂,全新世以来发生过至少2次古地震。在近1ka以来至少存在一次最新的古地震事件。  相似文献   

6.
准噶尔南缘逆冲带多个逆冲断层同期活动的几何学证据   总被引:1,自引:0,他引:1  
天山北缘为典型的大陆内部活动构造特征,发育准噶尔盆地南缘逆冲带,主要表现为新生代时期形成的多排平行山体的背斜和逆冲断层。野外地质考察、地表填图指出,第二排背斜带玛纳斯背斜和吐谷鲁背斜核部均发育一条逆冲断层,背斜北翼发育一条逆冲断层,并导致河流阶地变形和断层崖的形成。地震资料解释和钻井数据证实玛纳斯背斜和吐谷鲁背斜北翼和核部存在多条向北逆冲的断层,在这些背斜和南侧第一排构造清水河背斜和奇古背斜之间的向斜之下存在隐伏的东湾背斜。二维地震测网构造解释指出东湾背斜为同时活动的、叠置的双重逆冲构造,并造成玛纳斯背斜和吐谷鲁背斜浅层发育一系列无序叠瓦逆冲断层。野外观察和地震解释的生长地层和地层不整合分析证实,这些无序逆冲断层形成时间主要为中新世晚期,一直到第四纪西域组(Q_1x)和乌苏群(Q_2)时期和第四纪中晚期(Q_4)。我们提出准南地区多个逆冲断层同期活动模式不同于新逆冲断层向前陆方向扩展时,旧断层不活动的模式。同期逆冲作用模式展示由于深部有序逆冲作用形成的双重逆冲构造发育期间,同期活动的逆冲作用可在浅层地表形成一系列无序逆冲断层,类似于叠瓦扇逆冲断层。  相似文献   

7.
准噶尔盆地南缘前陆冲断带位于天山北麓,在晚新生代强烈的挤压作用下,地表发育数排背斜带。由于构造变形复杂、地震反射成像质量较差,对深层地质结构争议较大,另外前新生代盆地原型对晚新生代以来的褶皱冲断带构造格局的影响也尚未探讨。霍尔果斯—玛纳斯—吐谷鲁(简称霍-玛-吐)褶皱冲断带位于准噶尔盆地南缘前陆冲断带地表第二排背斜带,利用最新采集和处理的地震反射资料,并结合地表地质露头建立深层构造模型;利用平衡地质剖面复原和构造物理模拟实验的方法探索早侏罗世盆地原型结构对现今褶皱冲断带构造格局的影响;在此基础上分析霍-玛-吐褶皱冲断带深层天然气富集规律。霍-玛-吐褶皱冲断带垂向上发育古近系—第四系逆冲推覆构造、中上侏罗统—白垩系构造楔和下侏罗统半地堑断陷结构。控制早侏罗世半地堑系统的高角度正断层在晚期挤压构造变形体系中充当逆断坡,并控制上覆构造楔和浅层逆冲推覆构造的发育。早侏罗世半地堑系统具有分段性,并通过侧向断坡进行连接,侧向断坡上覆地层发育南北向走滑调节断层。油气勘探现状表明,霍-玛-吐褶皱冲断带内部南北向走滑调节断层具有高效沟通下侏罗统烃源岩的特点,是控制天然气的富集的重要因素。以上研究表明,中西部陆内前陆冲断带前新生代古构造对于晚新生代挤压冲断构造格局和深层天然气富集规律具有重要意义。  相似文献   

8.
晚新生代温泉沉积盆地,是青藏高原腹地在南北向挤压、东西向伸展的构造背景下,沿南北向边界走滑断层,经边界正断层和内部张剪断层的进一步发展而形成的近南北向单断单剪楔形半地堑活动沉积盆地.它可能代表了晚新生代青藏高原第三期强烈挤压隆升事件,是侧向向东剪切挤出的结果.笔者以盆地充填序列和TL、ESR测年资料为主要依据,推测唐古拉山在300~250ka前后全面进入冰冻圈;而以温泉活动沉积盆地为代表的中更新世晚期 (224.0~150.2ka)的冰碛冰水堆积则对应于青藏高原第三期隆升的断陷盆地发育阶段;中更新世晚期椡砀率乐衅?144.0~56ka)为湖相沉积;晚更新世中期至今(35~0ka)对应于高原缓慢隆升与夷平发育阶段.长江溯源在35ka切割通天河盆地,形成通天河;而在16ka侵蚀切穿雁石坪温泉兵站峡谷,形成布曲河.  相似文献   

9.
鄂西黄陵穹窿三斗坪地区新生代隆升特征研究   总被引:6,自引:0,他引:6  
位于湖北省西部的黄陵穹窿具有基底加盖层双层结构,其暴露的基底主要以黄陵花岗岩为代表.该穹窿对长江三峡的形成演化、四川-江汉盆地一带构造格局的形成,以及三峡大坝的安全性等方面均具有重要控制和影响作用.本文通过对黄陵花岗岩的裂变径迹特征分析,结合夷平面分析和野外实测阶地地貌数据,获得了黄陵穹窿自65Ma以来的隆升速率、隆升高度等方面的数据:① 65~7Ma,隆升速率为24.6~7.4m/Ma,隆升高度为1426.8~429.2m;②7Ma至今,平均隆升速率为204.1m/Ma,隆升高度为1428.7m.其中7~0.73Ma,隆升速率由0.009~0.013m/ka增加至0.293~0.387m/ka;而0.73~0.01Ma以来隆升速率由0.058m/ka增加为1.033m/ka,平均隆升速率为0.134m/ka,显示出隆升早期较慢,后期加快的趋势.65Ma以来,总的剥蚀厚度至少为2455.5~1457.9m,其中7Ma以来剥蚀的厚度为1028.7m,剥蚀速率为0.147mm/a.研究结果表明,该区的隆升历史,与青藏高原的形成演化密切相关,同时约束了长江三峡的形成时间和过程,证实了三峡是一年轻的河谷;该区隆升所引发的地表活动也可能会对三峡大坝产生一定的影响.  相似文献   

10.
循化-化隆盆地新生代沉积及盆地基底和周缘山系磷灰石裂变径迹年代学分析揭示了青藏高原东北缘晚白垩世以来经历过3期隆升剥露事件: (1)盆地基底及拉脊山和西秦岭北缘构造带磷灰石裂变径迹年龄分析普遍记录了晚白垩世-始新世中期相对快速的区域性的隆升剥露事件, 西秦岭北缘快速抬升的起始时间为84Ma, 受控于向北的逆冲抬升; 向北到循化-化隆盆地中部的拉目峡抬升的起始时间为69Ma; 更北的拉脊山一带快速抬升期主要为40~50Ma, 从而反映晚白垩世-始新世中期的快速抬升由南向北逐渐扩展.这一期构造隆升事件导致循化-化隆盆地和临夏盆地缺失了北部西宁-民和盆地古近纪所具有的西宁群沉积.隆升剥露结束于31Ma左右, 此时化隆-循化盆地向东与同时期的临夏盆地相连为一个统一的大型西秦岭山前盆地, 两者具有相同的构造、沉积演化史, 因此循化-化隆盆地他拉组底部地层年龄最老不会超过临夏盆地最老地层的古地磁年龄, 即29Ma.(2)渐新世晚期约26Ma拉脊山开始双向逆冲隆升, 并可能延续到中新世早期约21Ma, 隆升作用使循化-化隆盆地成为挟持于拉脊山逆冲带和西秦岭构造带之间的山前挤压型前陆盆地, 循化-化隆盆地开始大规模沉积巨厚的他拉组冲积扇相粗碎屑岩.(3)通过循化-化隆盆地咸水河组和临夏组的沉积相分析、古流方向和砾石成分分析, 揭示出拉脊山构造带在中新世8Ma左右发生的最大规模的双向逆冲隆升事件, 这次事件直接导致循化-化隆盆地由前陆挤压盆地转变为山间盆地, 形成现今青藏高原东北缘的盆山地貌基本格局.   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.
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.
塘口水电站大坝基础座落在断层和裂隙较发育的龟裂纹灰岩上,岩体完整性差、透水性强,多年运行后,大坝灌浆廊道和排水廊道出现多处集中性漏水,为确保大坝安全和电站正常发电,根据渗漏性质和成因,采用对灌浆廊道补充帷幕灌浆,对排水廊道进行固结+帷幕+回填灌浆。通过灌浆处理后,效果良好,表明灌浆工程有效的将导致坝基渗漏的上下游的裂隙通道封闭,并顺利的经受了随后的汛期洪水考验,大坝安全得到保障。  相似文献   

15.
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.
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.
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.
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.
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