中国西南天山西域砾岩的磁性地层年代与地质意义^*   总被引：11，自引：5，他引：11  

陈杰  R.V.Heermance  D.W.Burbank  K.M.Scharer  王昌盛 《第四纪研究》2007,27(4):576-587

西域组是我国西部一重要并广泛引用的晚新生代地层,关于其年代和成因至今尚存争议。在西南天山喀什远源盆地喀什-阿图什褶皱带不同构造部位选择有代表性的5~6个晚新生代地层剖面开展了详细的沉积学、磁性地层年代学对比研究,据此限定了不同构造的起始变形时间以及西域砾岩的沉积年代。西域砾岩并非一年代地层单位,作为一岩石地层单位,其底界具有穿时特征,从山体(北)向喀什前陆盆地(南)逐渐变新。其底界年龄在盆地北部近源区约为15.5Ma^[1],在盆地中部中源区约为8.6Ma^[1],在盆地南部远源区的阿图什背斜为1.9Ma,喀什背斜为1.6~0.7Ma。这一穿时的砾岩沉积楔体的起始堆积起因于盆地北部边界逆冲断层(KBT)的活动。构造变形是由北南脉冲式迁移扩展的,其速率是非均匀的,在约15.5Ma至4.0Ma期间为1.4~3.4mm/a,在约4.0Ma以来剧增至>10mm/a。西域砾岩沉积前缘向南进积速率与构造变形前缘迁移速率有很好的一致性,但在时间上较构造变形可能滞后2.0Ma。这表明构造变形前缘向南的脉冲式扩展是西域砾岩进积并发生侧向和垂向上岩相突变的主因。  相似文献   

Seismogenic destruction of the Kamenka medieval fortress, northern Issyk-Kul region, Tien Shan (Kyrgyzstan)     

Andrey M. Korjenkov  J. Ramon Arrowsmith  Christopher Crosby  Ernes Mamyrov  Lyubov A. Orlova  Irina E. Povolotskaya  Kubatbek Tabaldiev 《Journal of Seismology》2006,10(4):431-442

A paleoseismological study of the medieval Kamenka fortress in the northern part of the Issyk-Kul Lake depression, northern Tien Shan in Kyrgyzstan, revealed an oblique slip thrust fault scarp offsetting the fortification walls. This 700 m long scarp is not related to the 1911 Kebin Earthquake (Ms 8.2) fault scarps which are widespread in the region. As analysis of stratigraphy in a paleoseismic trench and archaeological evidence reveal, it can be assigned to a major twelfth century a.d. earthquake which produced up to 4 m of oblique slip thrusting antithetic to that of the nearby dominant faults. The inferred surface rupturing earthquake apparently caused the fortress destruction and was likely the primary reason for its abandonment, not the Mongolian–Tatar invasions as previously thought.  相似文献   

龙门山前陆褶皱冲断带构造解析与川西前陆盆地的发育   总被引：57，自引：2，他引：55  

贾东  陈竹新  贾承造  魏国齐  李本亮  张惬  魏东涛  沈扬 《高校地质学报》2003,9(3):402-410

通过详细的野外地质调查和精细的地震剖面构造解析。揭示了龙门山前陆褶皱冲断带的基本构造特征。对比分析了龙门山北段与南段构造变形几何学和运动学的差异。提出龙门山北段主要表现为一系列复杂的逆冲推覆构造,晚三叠纪变形强于新生代;龙门山南段则以基底卷入的叠瓦状冲断为特点,晚白垩纪-早第三纪变形尤为突出。与前陆褶皱冲断带相对应的是,川西晚三叠纪时期的周缘前陆盆地主要表现在整个龙门山褶皱冲断带的前渊地区;而晚白垩纪-早第三纪再生前陆盆地却局限在川西盆地的南部,并且印-藏碰撞的持续挤压作用使得晚新生代构造变形不断向东扩展进入川西盆地南部。  相似文献   

六盘山弧形构造带铜多金属矿床的成矿环境   总被引：1，自引：0，他引：1  

张韬  林畅松  丁孝忠  杜玉良  翟刚毅  张文秦 《地球学报》2002,23(6):553-558

六盘山弧形构造带位于青藏高原东北缘,自震旦-寒武纪以来,经历了“威尔逊旋回“构造演化。在陆内裂谷和板块俯冲阶段,成矿类型主要为海底火山块状硫化物型和与韧性剪切作用有关的构造蚀变岩型,而在碰撞造山和陆内造山阶段,成矿类型演变为与大型推覆体构造有关的似层状热液型,显示出不同构造演化阶段所反映的成矿环境不同。  相似文献   

Late-Stage Ductile Deformation in Xiongdian-Suhe HP Metamorphic Unit, North-Western Dabie Shan, Central China     

SuoShutian ZhongZengqiu ZhouHanwen YouZhendong 《中国地质大学学报(英文版)》2004,15(3):262-274

New structural and petrological data unveil a very complicated ductile deformation history of the Xiongdian-Suhe HP metamorphic unit, north-western Dabie Shun, central China. The finegrained symplectic amphibolite-facies assemblage and coronal structure enveloping eclogite-facies garnet,omphacite and phengite etc., representing strain-free decompression and retrogressive metamorphism,are considered as the main criteria to distinguish between the early-stage deformation under HP metamorphic conditions related to the continental deep subduction and collision, and the late-stage deformation under amphibolite to greenschist-facies conditions occurred in the post-eclogite exhumation processes.Two late-stages of widely developed, sequential ductile deformations D3 and D4, are recognized on the basis of penetrative fabrics and mineral aggregates in the Xiongdian-Suhe HP metamorphic unit, which shows clear, regionally, consistent overprinting relationships. D3 fabrics are best preserved in the Suhe tract of low post-D3 deformation intensity and characterized by steeply dipping layered mylonitic amphibolites associated with doubly vergent folds. They are attributed to a phase of tectonism linked to the initial exhumation of the HP rocks and involved crustal shortening with the development of upright structures and the widespread emplacement of garnet-bearing granites and felsic dikes. D4 structures are attributed to the main episode of ductile extension (D^24) with a gently dipping foliation to the north and common intrafolial, recumbent folds in the Xiongdian tract, followed by normal sense top-to-the northductile shearing (D^24) along an important tectonic boundary, the so-called Majiawa-Hexiwan fault (MHF), the westward continuation of the Balifan-Mozitan-Xiaotian fault (BMXF) of the northern Dabie Shan. It is indicated that the two stages of ductile deformation observed in the Xiongdian-Suhe HP metamorphic unit, reflecting the post-eclogite compressional or extrusion wedge formation, the subhorizontal ductile extension and crustal thinning as well as the top-to-the north shearing along the high-angle ductile shear zones responsible for exhumation of the HP unit as a coherent slab, are consistent with those recognized in the Dabie-Sulu UHP and HP metamorphic belts, suggesting that they were closely associated in time and space. The Xiongdian-Suhe HP metamorphic unit thus forms part of the Triassic(250-230 Ma) collision orogenic belt, and can not connect with the South Altun-North Qaidam-North Qinline UHP metamorphic belt formed durin~ the Early Paleozoic (500-400Ma).  相似文献   

Late Cenozoic Tectonics Along the Northwestern Margin of the Tarim Basin: Interactions Between the Tarim Basin and the Southern Tian Shan, West China     

Chen Jie  Qu Guosheng  Shen Jun  Edward Sobel  Nan Ling  Tian Qinjian  Yin Jinhui 《地学前缘》2000,(Z1)

LATE CENOZOIC TECTONICS ALONG THE NORTHWESTERN MARGIN OF THE TARIM BASIN: INTERACTIONS BETWEEN THE TARIM BASIN AND THE SOUTHERN TIAN SHAN, WEST CHINAgrants 4 98340 50and 4 9732 0 90fromtheNSFofChina;;andproject96 913 0 7 0 1fromtheMinistryofSci enceandTechnology ,China…  相似文献   

大别山双河和碧溪岭超高压变质岩流体包裹体研究   总被引：9，自引：2，他引：7  

傅斌  肖益林 《岩石学报》2000,16(1):119-126

对大别山双河和碧溪岭含柯石英榴岩和硬玉石英岩进行了详细的流体包裹体研究。根据流体包裹体的成分和盐度的不同,可以划分出至少五种类型不同的气液包裹体;（１）Ｎ２包裹体;（３）高盐度流体包裹体;（３）ＣＯ２包裹体;（４）ＣＯ２－Ｈ２Ｏ包裹体;（５）低盐度流体包裹体。本仅见于含柯石英榴辉岩,而高盐度流体包裹体则几乎存在于所有的榴辉岩和硬玉石英岩中。ＣＯ２包裹体沿榴辉岩中微剪切带分布,或存在于强变形的硬玉石  相似文献   

STUDY ON PALEOEARTHQUAKES ALONG THE JINGHE SECTION OF BOLOKENU-AQIKEKUDUKE FAULT          下载免费PDF全文

HU Zong-kai  YANG Xiao-ping  YANG Hai-bo  WU Guo-dong  LI Jun  ZHOU Ben-gang 《地震地质》1979,42(4):773-790

The Bolokenu-Aqikekuduk fault zone(B-A Fault)is a 1 000km long right-lateral strike-slip active fault in the Tianshan Mountains. Its late Quaternary activity characteristics are helpful to understand the role of active strike-slip faults in regional compressional strain distribution and orogenic processes in the continental compression environment, as well as seismic hazard assessment. In this paper, research on the paleoearthquakes is carried out by remote sensing image interpretation, field investigation, trench excavation and Quaternary dating in the Jinghe section of B-A Fault. In this paper, two trenches were excavated on in the pluvial fans of Fan2b in the bulge and Fan3a in the fault scarp. The markers such as different strata, cracks and colluvial wedges in the trenches are identified and the age of sedimentation is determined by means of OSL dating for different strata. Four most recent paleoearthquakes on the B-A Fault are revealed in trench TC1 and three most recent paleoearthquakes are revealed in trench TC2. Only the latest event was constrained by the OSL age among the three events revealed in the trench TC2. Therefore, when establishing the recurrence of the paleoearthquakes, we mainly rely on the paleoearthquake events in trench TC1, which are labeled E1-E4 from oldest to youngest, and their dates are constrained to the following time ranges: E1(19.4±2.5)~(19.0±2.5)ka BP, E2(18.6±1.4)~(17.3±1.4)ka BP, E3(12.2±1.2)~(6.6±0.8)ka BP, and E4 6.9~6.2ka BP, respectively. The earthquake recurrence intervals are(1.2±0.5)ka, (8.7±3.0)ka and(2.8±3)ka, respectively. According to the sedimentation rate of the stratum, it can be judged that there is a sedimentary discontinuity between the paleoearthquakes E2 and E3, and the paleoearthquake events between E2 and E3 may not be recorded by the stratum. Ignoring the sedimentary discontinuous strata and the earthquakes occurring during the sedimentary discontinuity, the earthquake recurrence interval of the Jinghe section of B-A Fault is ~1~3ka. This is consistent with the earthquake recurrence interval(~2ka)calculated from the slip rate and the minimum displacement. The elapsed time of the latest paleoearthquake recorded in the trench is ~6.9~6.2ka BP. The magnitude of the latest event defined by the single event displacement on the fault is ~M_W7.4, and a longer earthquake elapsed time indicates the higher seismic risk of the B-A Fault.  相似文献   

Metamorphic veins with kyanite, zoisite and quartz in the Zhu-Jia-Chong eclogite, Dabie Shan, China   总被引：13，自引：0，他引：13  

Daniele Castelli  Franco Rolfo  Roberto Compagnoni  & Shutong Xu 《Island Arc》1998,7(1-2):159-173

  相似文献   

双峰山金矿床地质特征及成因探讨   总被引：4，自引：0，他引：4  

席小平 《矿产与地质》1999,13(1):28-33

双峰山金矿产于双峰山背斜核部下石炭统巴塔玛依内山组第二亚组陆相火山岩内。即金矿化赋存于次生石英岩及蚀变安山岩中。金矿化与硅化、黄铁矿化关系密切,矿床具有Ａｕ、Ａｇ、Ａｓ、Ｓｂ、Ｈｇ等元素组合异常,表现出浅成低温热液矿化蚀变特征。提出了双峰山金矿为浅成低温热液型冰长石—绢云母金矿亚型矿床的成因认识。  相似文献