共查询到20条相似文献，搜索用时 109 毫秒
1.
CENOZOIC SEDIMENTARY SEQUENCE IN THE KUMUKULI BASIN, XINJIANG AND NEW EVIDENCE ON LATE QUATERNARY UPLIFT OF THE QINGHAI—TIBETAN PLATEAU 相似文献
2.
PALEOGENE(?) DEPOSYSTEMS AND BASIN EVOLUTION IN THE EASTERN TIBETAN PLATEAU: NANGQIAN AND XIALAXIU BASINS 总被引：1，自引：0，他引：1
PALEOGENE(?) DEPOSYSTEMS AND BASIN EVOLUTION IN THE EASTERN TIBETAN PLATEAU: NANGQIAN AND XIALAXIU BASINS 相似文献
3.
4.
THE TERTIARY STRATIGRAPHIC SEQUENCE OF YANYUAN BASIN IN THE SOUTHEASTERN MARGIN OF THE QINGHAI—TIBET PLATEAUYoungGeologistofGMR(Qn979816 )andNSFCGeneralProjects(4980 2 0 13) 相似文献
5.
QUATERNARY GROWTH FOLDS IN THE JIUXI BASIN AT THE NORTHEASTERN MARGIN OF THE QINGHAI—XIZANG PLATEAUgrants 49732 0 90and 496 0 2 0 36fromtheNSFofChina 相似文献
6.
MARINE SOURCE ROCKS AND THEIR DEPOSITIONAL CONDITIONS OF MESOZOIC—CENOZOIC IN THE GAMBA—TINGRE BASIN,SOUTH TIBET:ORGANIC GEOCHEMICAL STUDY1 FuJiamo ,ShengGuoying ,XuJiayou,et.al.ApplicationofbiologicalmarkersintheassessmentofpaleoenvironmentsofChinesenon marinesediments[J] .OrganicGeochemistry ,1990 ,16 :76 9～ 779.
2 JenkynsHC .Cretaceousanoxicevents:fromcontinentstooceans[J] .JournaloftheGeologicalSociety ,1980 ,137:171～188.
… 相似文献
7.
THE UPWARPING AND DOWNWARPING STRUCTURAL SYSTEM OF MOHO—SURFACE IN CHINESE AND NEAR REGION AND THE GENETIC MECHANICS OF QINGHAI—TIBET PLATEAU TECTONIC 相似文献
8.
CENOZOIC TECTONIC EVOLUTION AND GEODYNAMICS OF KEKEXILI BASIN IN NORTHERN QINGHAI—XIZANG PLATEAU 相似文献
9.
THE CENOZOIC GEORECORDS IN THE NORTHWEST OF YUNNAN AND THE EVOLUTION OF QING—ZANG PLATEAU 相似文献
10.
THE MESOZOIC QIANGTANG FORELAND BASIN IN QINGHAI—XIZANG PLATEAU,CHINANationalKeyFundamentalResearchProjects(973) (G1990 40 80 15 ) ;NSFCGeneralProjects(4980 2 0 13) 相似文献
11.
对北祁连造山带前寒武纪基底物性、火山岩的
源区性质及找矿问题的分析和综述 总被引：1，自引：0，他引：1
[摘 要]本文主要在先前一些研究者对北祁连山加里东造山带的构造、海相火山岩和块状硫化矿床研究所获成果和认识的基础上,重点从造山带的前寒武纪基底的物性特征,来分析和讨论所见不同时代地层中的变火山岩类的物源区及形成机制,进而提出一些区域找矿思路。所得结论主要包括:(1) 北祁连山加里东造山的真正基底应是从阿拉善或华北地块分裂出来的一套绿岩类型火山沉积建造,并以古元古宙的北大河群和龙首山群为代表;(2)北祁连造山带的基底从克拉通向大陆裂谷构造体制转换大致发生在早-中元古宙的分界时限(约1777Ma),并普遍以一套大陆裂谷型双峰式火山岩组合为典型特征;(3)不同时代或不同构造体制下形成的火山岩,各有其不同的物源区和成岩模式。具体说,在元古宙
绿岩类型的火山岩的源区可能是克拉通早期由原始玄武质下地壳转变来榴辉岩或基性麻粒岩相,进入大陆裂谷构造体阶段,便转换为一种幔-壳双层岩源区模型,而晚期的次火山岩类的源岩明显是已经过先期大量改造或改变了中上地壳物质作为物源;(4) 按大陆裂谷成矿体系并结合以往一些区域调查资料,提出托莱山西段的小龙口-九个青羊地段可能是个与海相火山岩有关的块状硫化物矿床潜在远景找矿地段。 相似文献
12.
The middle Qilian orogenic belt and Lajishan orogenic belt, both of which were formed in the Caledonian, strike NW-SE direction across southeast Qilian Mountains and their basement consists of pre-Caledonian metamorphic rocks with lozenge-shaped ductile shear zones in the crystalline base- ment. The blunt angle between the conjugated ductile shear zones ranges from 104° to 114°, indicating approximate 210° of the maximum principal stress. The plateau ages of muscovite 40Ar/39Ar obtained from the mylonitized rocks in the ductile shear zones of Jinshaxia-Hualong-Keque massif within the middle Qilian massif are (405.1±2.4) Ma and (418.3±2.8) Ma, respectively. The chronology data confirm the formation of ductile shear zones in the Caledonian basement metamorphic rocks during the Cale- donian orogeny. Furthermore, on the basis of basement rock study, precise timing for the closing of the Late Paleozoic volcanic basin (or island-arc basin) and Lajishan ocean basin is determined. This pro- vides us a new insight into the closing of ocean basin in the structural evolution of orogenic belt. 相似文献
13.
从弧后盆地到前陆盆地——北祁连造山带奥陶纪—泥盆纪的沉积盆地与构造演化 总被引：4，自引：0，他引：4
北祁连加里东期造山带是在新元古代Rodinia联合大陆(Pangea-850)基础上裂解,经由寒武纪裂谷盆地、奥陶纪初期成熟洋盆、奥陶纪中晚期北祁连活动大陆边缘、志留纪—早、中泥盆世碰撞造山而形成的。奥陶纪中、晚期,北祁连、走廊地区中、上奥陶统发育洋壳-岛弧-弧后火山岩,形成典型的沟-弧-盆体系的沉积。志留纪—早、中泥盆世是北祁连-走廊沉积盆地的转换时期。除天祝、古浪、景泰及肃南等局部地区发育下志留统钙碱性系列火山岩以外,全区志留系均以碎屑岩沉积为主。志留系底部多见一套砾岩层。下—中志留统为典型复理石相的浊流沉积。上志留统变为滨浅海相磨拉石沉积。早、中泥盆世雪山群为典型的陆相粗碎屑磨拉石沉积。从空间分布上看,志留系—泥盆系在走廊—北祁连地区也有自北向南厚度加大、粒度变粗的特征,古流以由南向北、来自造山带的古流为特征。北祁连-河西走廊奥陶纪弧后盆地火山岩—志留系复理石-海相磨拉石—中、下泥盆统陆相磨拉石的充填序列以及空间分布特点,反映为典型的弧后盆地向前陆盆地转化的沉积序列。 相似文献
14.
祁连山东南段加里东造山期构造变形年代的精确限定及其意义 总被引：8，自引：0，他引：8
祁连山东南段呈北西-南东向展布着加里东期中祁连造山带和拉脊山造山带, 其基底为前加里东变质岩系, 在该变质结晶基底岩系中发育着菱形网格状韧性剪切带, 共轭韧性剪切带面对缩短方向的夹角为104°~114°, 其最大主应力方位为SW210°左右.在中祁连地块金沙峡和化隆地块科却两处韧性剪切带中的糜棱岩化岩石, 获取变质矿物白云母40Ar-39Ar坪年龄分别为(405.1±2.4) Ma和(418.3±2.8) Ma.这一年代学结果不仅确定了加里东基底变质岩系中韧性剪切带是加里东造山作用过程中形成, 更重要的是通过对基底韧性剪切带中变质变形岩石的年代学研究, 精确地限定了祁连山东南段的早古生代火山盆地(或岛弧盆地)、拉脊山小洋盆关闭的构造年代.这为造山带构造演化过程中盆地关闭时间的确定开辟了新的途径. 相似文献
15.
北祁连山俯冲杂岩带的构造演化 总被引：76，自引：2，他引：76
北祁连位位于华北克拉西部阿拉善地块与中祁连－柴达木泛地块之间是我国最具特色的大陆造山带之一。带内发育有震旦纪－中寒武世的裂谷火山岩，晚寒武世－奥陶纪蛇绿岩，中晚奥陶世岛弧火山岩，晚奥陶世弧后拉张盆地火山－沉积岩，志留纪残余海盆相复理石和泥盆纪山间磨粒石等，中间夹两条变质和变形特征不同的加里东期俯冲杂岩带；南带为深层俯冲，北带为浅层俯冲杂岩；这两条杂岩石可能形成于同一俯冲带的不同深度，俯冲杂岩带中岩 相似文献
16.
天水渭北地区的变质花岗岩类地质特征 总被引：1，自引：1，他引：1
天水渭北地区地处祁连与北秦岭造山带结合部位。通过详细的岩石学特征、接触关系、形变及变质特征研究，从变质地层中识别和解体出众多的变质花岗岩体。主要成岩期及代表性岩类有：中元古界为片麻状花岗闪长岩-二长花岗岩，震旦纪为片理化闪长岩。采用多种构造判别图解，获得了重要的构造环境信息。中元古界的花岗岩类是板块碰撞前过渡性结晶基底上局部熔融花岗岩类。震旦纪花岗岩类与板块碰撞作用密切有关，是碰撞造山一碰撞后抬升这一过程形成的花岗岩类。花岗岩类记录了祁连地块与秦岭地块碰撞的重要证据。 相似文献
17.
DuYuansheng WangJiasheng HanXin ShiGR 《中国地质大学学报(英文版)》2003,14(1):1-7
The Late Caledonian to Early Hercynian North Qilian orogenic belt in northwestern China is an elongate tectonic unit situated between the North China plate in the north and the Qaidam plate in the south. North Qiilan started in the latest Proterozoic to Cambrian as a rift basin an the southern mar-gin of North China, and evolved later to an archipelagic ocean and active continental margin during the Ordovician and a fardand basin from Silurian to the Early and Middle Devonian. The Early Silurian fly-sch and sulmmrine alluvial fan, the Middle to Late Silurian shallow marine to tidal flat deposits and the Early and Middle Devonian terrestrial.molasse are developed along the corridor Nansimn. The shallo-wing-upward succession from subabyssal flysch, shallow marine, tidal flat to terrestrial molasse and its gradually narrowed regional distribution demonstrate that the foreland basin experienced the transition from flysch stake to molasse stake during the Silurian and Devonian time. 相似文献
18.
19.
北祁连造山带是一条多旋回的造山带,其最大特点是早古生代岩系中镶嵌有众多大小不一的由前震旦系变质岩系所组成的陆壳残块群,它们源于晋宁期末,统一的巨型华北古大陆早古生代初的裂解。寒武 奥陶纪西段演化为裂谷系,陆壳残块群组成裂谷系的正性隆起构造单元;中段发育微洋盆沟弧盆体系,在南缘的陆壳残块群处于奥陶纪活动大陆边缘张裂带上,并构成被晚期弧后盆地及裂谷分开后的陆壳基底部位,少数陆壳残块为沟弧盆体系中的孤岛隆起。它们不是由中祁连推覆来的飞来峰或是外来移置的滑覆体,而是由统一的巨型华北古大陆西南缘古阿拉善地块于早古生代初裂解后向洋或裂谷演化过程中残留其中的大小不一的陆壳残块。北祁连早奥陶世海域与现在加拿大北部巴芬湾及伊丽莎白女王群岛的构造格局相似。 相似文献
20.
The North Qilian orogenic belt is an elongate tectonic unit that lies between the North China plate to the north and the Middle
Qilian microplate to the south, and is formed by a collision of the two plates in the Caledonian. The Shihuigou Section from
Yongdeng County, Gansu Province, is in the eastern sector of the North Qilian Mountains, spanning the Ordovician island-arc
zones. The Zhongpu Group is distributed in the Shihuigou area and composed of medium-basic volcanic rocks and volcanic clastic
rocks interspersed with cherts, limestones, slates, and metamorphic sandstones. The geochemistry of chert from the Zhongpu
Group reveals that all cherts coexisting with island-arc volcanic rocks formed in a continental margin basin environment.
Research results of the rare earth elements reveal that these cherts formed in a relatively deep-water basin with no significant
terrestrial interference. Therefore, it is inferred that the North Qilian orogenic belt was previously an archipelagic ocean
in the Ordovician.
Translated from Geological Review, 2006, 52(2): 184–189 [译自: 地质论评] 相似文献