共查询到20条相似文献，搜索用时 62 毫秒
1.
郯庐断裂带东侧华南地块部分逆时针转动——古地磁新证据 总被引：3，自引：0，他引：3
本文对郯庐断裂带东西两侧的莱阳、六安、庐枞和怀宁等中新生代盆地内的中三叠世至早白垩世沉积构造变形进行了古地磁研究。采样区大多数特征磁化方向通过了褶皱检验或反极性检验,从上述地区共获得了10个可靠的中三叠世-早白垩世的古地磁极。该结果与华南地块的视极移曲线对比,可以看出,从中侏罗世以来,郯庐断裂带东西两侧不存在大规模地水平相对位移。但是,断裂带东边的华南地块部分存在15°-25°的逆时针转动。这种转动主要应发生在晚侏罗世,主要与华南、华北地块的碰撞以及太平洋板块的挤压有关。 相似文献
2.
郯庐断裂带两侧的前陆沉积及其变形现象,揭示了该断裂带同造山活动的大量信息。合肥盆地东侧的郯庐断裂带旁,侏罗系沉积时出现了沉降中心与边缘相,显示这期间郯庐断裂带所处的张八岭隆起已移位至盆地东侧。砂岩的端元组份分析与碎屑白云母的电子探针分析显示,下扬子地区弧形展布的黄马青群与象山群前陆沉积的物源区为大别——苏鲁造山带,属于原地沉积,表明造山期郯庐断裂带已经出现。大别与苏鲁造山带周边都出现了强烈的前陆褶皱冲断带。合肥盆地前侏罗系基底上印支期的逆冲断层,在郯庐断裂带旁侧明显增多,指示该断裂带曾发生过同造山活动。下扬子地区前陆构造走向向郯庐断裂带方向偏转,反映它们形成时受到了郯庐断裂带左旋走滑运动的影响。这一系列前陆沉积与变形特征,指示郯庐断裂带在华北与华南板块的碰撞造山中以陆内变换断层的型式出现。该断裂带造山期运动中,东盘为主动盘,并发生了显著的逆时针旋转。独特的徐宿弧形逆冲——推覆构造,表明造山期郯庐断裂带左行平移幅度达350km。在该断裂带早白垩世的第二次平移中,断裂带向北延伸,又发生了约200km的左行平移。 相似文献
3.
胶莱盆地构造演化规律 总被引：11，自引：0，他引：11
胶莱盆地是中生代走滑拉分盆地，其形成与发育受到沂沭断裂和五莲—即墨—牟平断裂的控制。从晚侏罗世—晚白垩世经历了莱阳期、青山期和王氏期的盆地发展阶段。构造活动使不同时期的盆地格局发生改变，不同阶段盆地的次级构造单元也随之变化。不同阶段次级构造单元的形成与演变反映了构造活动对盆地发育的控制作用，表现在各单元之间沉积相发生突变。扬子板块与华北板块的碰撞，控制郯庐断裂带(沂沭断裂带)和五莲—即墨—牟平断裂的运动方向和强度，进而控制胶莱盆地的形成与发育。同时盆地发育也受到太平洋板块的影响与控制。 相似文献
4.
5.
郯庐断裂带在造山阶段之后发生了明显的左行平移活动,但到目前为止对于其发生时间仍存在较大争议。大别山东缘郯庐断裂带内存在一系列花岗质、基性岩脉,其形成与郯庐断裂带左行平移活动密切相关,因而对其形成年龄的测定可以为断裂带左行平移时间提供限定。本次工作在大别山东缘郯庐断裂带内糜棱岩及岩脉中采集了6个样品开展锆石LA-ICP-MS年龄测定。两个花岗质糜棱岩样品均得到了新元古代和印支期两组年龄结果,但并未得到早白垩世年龄结果,可能指示了强烈的构造变形抑制了锆石的生长。与断裂带左行平移活动同期的基性岩墙侵位时间为128 Ma左右;斜切糜棱岩面理的基性岩墙侵位于127 Ma 左右;发生韧性变形形成糜棱岩的二长花岗岩侵位时间为128 Ma左右;仅出现NE向劈理的钾长花岗岩侵位于126 Ma。综合以上结果,大别山东缘郯庐断裂带与下扬子地区存在类似的构造背景,其早白垩世左行平移事件的发生时间为128 Ma之前,之后断裂带在区域伸展背景下转变为正断层活动。 相似文献
6.
7.
合肥盆地的沉积作用与其东缘的郯庐断裂带演化有着良好的耦合关系。侏罗纪盆地发育主要受大别造山带演化控制,东部可见对同造山期郯庐断裂带左旋转换走滑的沉积响应。盆地内朱巷组的沉积是对早白垩世早期郯庐断裂再次发生陆内左行平移的响应,该时期成盆模式为一走滑—挠曲盆地。盆地内上白垩统—古近系的形成是对这期间郯庐断裂带伸展活动的响应,盆地具区域性伸展(双向伸展)的特征。盆地东部自新近纪以来的抬升、消亡与东缘反转构造的存在,指示了郯庐断裂带的逆冲活动。盆地东部的沉积记录结合近年来郯庐断裂带内部构造与同位素年代学的最新研究成果,指示该断裂带中-新生代经历了4个演化阶段:同造山期的左旋转换走滑、早白垩世早期的陆内左行平移、晚白垩世—古近纪的伸展运动和新近纪以来的逆冲活动。 相似文献
8.
沂沭断裂带内盖层的剪切变形及其构造意义 总被引：3，自引：0，他引：3
通过沂沭断裂带内晚元古代至古代盖层变形的详细研究，发现这套盖层遭受了明显的顺层左旋走滑剪切变形。这期盖层变形是与沂沭断裂带基底中北北东走向左行韧性剪切带同期形成的。它们是郯庐断裂带中生代大规模左行平移运动在不同层次上所造成的不同产物。这套盖层的变形及其特征证明了郯庐断裂带大平移发生在中生代。 相似文献
9.
通过沂沭断裂带内晚元古代至古生代益层变形的详细研究，发现这套盖层遭受了明显的顺层左旋走滑剪切变形。这期盖层变形是与沂沭断裂带基底中北北东走向左行韧性剪切带同期形成的。它们是郯庐断裂带中生代大规模左行平移运动在不同层次上所造成的不同产物。这套益层的变形及其特征证明了郯庐断裂带大平移发生在中生代。 相似文献
10.
与时俱进,发展中国大地构造学 总被引：38，自引：1，他引：38
郯庐断裂带的起源时间与型式仍然存在着很大的分歧。最近在大别山东缘早白垩世左旋走滑韧性剪切带中 ,发现了早期左旋走滑韧性剪切带。其中三处早期糜棱岩中白云母分别给出了( 188.7± 0 .7)Ma、( 189.7± 0 .6 )Ma、( 192 .5± 0 .7)Ma的40 Ar/ 3 9Ar坪年龄 ,指示了同造山走滑热事件。前陆沉积与变形构造也表明该断裂带在华北与华南板块碰撞中就发生了活动。郯庐断裂带内的造山期构造及旁侧的前陆沉积与变形构造特征 ,指示断裂带同造山运动为转换断层型式 ,并将大别—苏鲁造山带左行错移了约 35 0km ,同时苏鲁造山带发生逆时针旋转。在早白垩世滨太平洋构造活动中 ,该断裂进一步向北延伸 ,发生了约 2 0 0km的左行平移。因而 ,该断裂带起源于华北与华南板块的碰撞之中 ,其同造山运动与这两大板块的碰撞过程相伴生 相似文献
11.
Gilles Serge Odin 《Comptes Rendus Geoscience》2002,334(6):409-414
Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414. 相似文献
12.
Inter-regional correlation of transgressions and regressions in the Cretaceous period 总被引：1，自引：0，他引：1
T. Matsumoto 《Cretaceous Research》1980,1(4):359-373
Well investigated platforms have been selected in each continent, and the history of Cretaceous transgressions and regressions there is concisely reviewed from the available evidence. The factual records have been summarized into a diagram and the timing of the events correlated between distant as well as adjoining areas.On a global scale, major transgressions were stepwise enlarged in space and time from the Neocomian, via Aptian-Albian, to the Late Cretaceous, and the post-Cretaceous regression was very remarkable. Minor cycles of transgression-regression were not always synchronous between different areas. Some of them were, however, nearly synchronous between the areas facing the same ocean.Tectono-eustasy may have been the main cause of the phenomena of transgression-regression, but certain kinds of other tectonic movements which affected even the so-called stable platforms were also responsible for the phenomena. The combined effects of various causes may have been unusual in the Cretaceous, since it was a period of global tectonic activity. The slowing down of this activity followed by readjustments may have been the cause of the global regression at the end of the Cretaceous. 相似文献
13.
The Afyon stratovolcano exhibits lamprophyric rocks, emplaced as hydrovolcanic products, aphanitic lava flows and dyke intrusions, during the final stages of volcanic activity. Most of the Afyon volcanics belong to the silica-saturated alkaline suite, as potassic trachyandesites and trachytes, while the products of the latest activity are lamproitic lamprophyres (jumillite, orendite, verite, fitztroyite) and alkaline lamprophyres (campto-sannaite, sannaite, hyalo-monchiquite, analcime–monchiquite). Afyon lamprophyres exhibit LILE and Zr enrichments, related to mantle metasomatism. 相似文献
14.
正20140751 Guo Xincheng(Geological Party,BGMRED of Xinjiang,Changji 831100,China);Zheng Yuzhuang Determination and Geological Significance of the Mesoarchean Craton in Western Kunlun Mountains,Xinjiang,China(Geological Review,ISSN0371-5736,CN11-1952/P,59(3),2013,p.401-412,8 相似文献
15.
正20141058 Chen Ling(Key Laboratory of Mathematical Geology of Sichuan Province,Chengdu University of Technology,Chengdu610059,China);Guo Ke Study of Geochemical Ore-Forming Anomaly Identification Based on the Theory of Blind Source Separation(Geosci- 相似文献
16.
正20141334 Chen Kun(Institute of Geophysics,China Earthquake Administration,Beijing100081,China);Yu Yanxiang Shakemap of Peak Ground Acceleration with Bias Correction for the Lushan,Sichuan Earthquake on April20,2013(Seismology and Geology,ISSN0253-4967,CN11-2192/P,35(3),2013,p.627-633,2 illus.,1 table,9 refs.)Key words:great earthquakes,Sichuan Province 相似文献
17.
正20141624 Cai Xiongfei(Key Laboratory of Geobiology and Environmental Geology,Ministry of Education,China University of Geosciences,Wuhan 430074,China);Yang Jie A Restudy of the Upper Sinian Zhengmuguan and Tuerkeng Formations in the Helan Mountains(Journal of Stratigraphy,ISSN0253-4959CN32-1187/P,37(3),2013,p.377-386,5 illus.,2 tables,10 refs.) 相似文献
18.
正20142263Lü Shaojun(Geological Survey of Jiangxi Province,Nanchang 330030,China)Early-Middle Permian Biostratigraphical Characteristics in Qiangduo Area,Tibet(Resources SurveyEnvironment,ISSN1671-4814,CN32-1640/N,34(4),2013,p.221-227,2illus.,2tables,22refs.)Key words:biostratigraphy,Lower Permian,Middle Permian,Tibet 相似文献
19.
正20142560Hu Hongxia(Regional Geological and Mineral Resources Survey of Jilin Province,Changchun 130022,China);Dai Lixia Application of GIS Map Projection Transformation in Geological Work(Jilin Geology,ISSN1001-2427,CN22-1099/P,32(4),2013,p.160-163,4illus.,2refs.) 相似文献
20.
正20140692 Duo Tianhui(No.402 Geological Team,Exploration of Geology and Mineral Resources of Sichuan Authority,Chengdu611730,China);Wang Yongli Computer Simulation of Neptunium Existing Forms in the Groundwater(Computing Techniques for Geophysical and Geochemical Exploration,ISSN1001-1749,CN51-1242/P,35(3), 相似文献