New paleontological evidence on time determination of the east part of the Eastern Kunlun Mélange and its tectonic significance     

ZHANG Kexin  LIN Qixiang  ZHU Yunhai  YIN Hongfu  LUO Mansheng  CHEN Nengsong  WANG Guocan 《中国科学D辑(英文版)》2004,47(10):865-873

New paleontological evidence suggests that the composition of the matrix and slices from the middle and the south of the Eastern Kunlun Melange Belt is very complex, ranging from Proterozoic to Mesozoic in geological time. A Cambrian acritarch assemblage has been discovered from the middle part of the Eastern Kunlun Melange, a Neoproterozoic to the early Paleozoic acritarch assemblage has been discovered from the south of the Eastern Kunlun Melange,and so has been an Early Permian radiolarian from the A'nyemaqen Melange in Buqingshan.In addition, some sporopollen has been obtained from the Mesozoic tectonic slices. The above-mentioned paleontological evidence indicates that the Eastern Kunlun Orogenic Belt experienced two episodes from ocean to continent from the Neoproterozoic to the Early Paleozoic and in the Late Paleozoic respectively. In the process of intracontinent development in Mesozoic, because of heavy thrust-nappe, strike-slip sheer and crust shortening, the Mesozoic formation was intercalated in melange by slices and the Eastern Kunlun Orogenic Belt became more complex.  相似文献   

东昆仑造山带东段清水泉高级变质岩片的变质岩石学研究   总被引：15，自引：0，他引：15       下载免费PDF全文

陈能松  朱杰  王国灿  侯光久  张克信  朱云海  拜永山 《地球科学》1999,24(2):116-120

清水泉高级变质岩片位于东昆仑造山带东段昆中多旋回俯冲碰撞构造混杂岩带内,由高角闪岩相—麻粒岩相变质的麻粒岩、斜长角闪岩、片麻岩、变粒岩和大理岩组成,地球化学特征显示为一套形成于后太古宙以来的火山－沉积岩系．顶峰期典型矿物共生组合为石榴石＋蓝晶石＋钾长石＋斜长石＋黑云母＋石英＋金红石和石榴石＋紫苏辉石＋斜长石＋石英,属中压相系,变质温度压力条件为（８５０±５０）℃和高于１．０ＧＰａ．石榴石中ｘ（Ｓｐｓ）成分剖面平坦,近边缘略为上升,ｘ（Ａｌｍ）,ｘ（Ｐｙｒ）和ｘ（Ｇｒｓ）仍保留了较好的生长环带特点．ｐ－ｔ轨迹为顺时针型,记录了古－中元古代之交或晋宁运动期间强烈的碰撞构造事件．  相似文献   

中、下地壳中长石的塑性变形机制及其证据——长石的显微构造研究综述     

王国灿 《地质科技情报》1993,12(3):18-24

综述了有关长石的碎裂流动、位错蠕变、扩散蠕变、颗粒边界滑动及超塑性流动的特点及有关现象,并指出了长石塑性变形机制研究的重要意义。  相似文献   

控制长石塑性变形机制转换的主要环境因素     

王国灿 《地质科技情报》1994,13(2):17-22

根据近年来有关长石的实验变形和自然变形研究的新成果，综述了环境因素对长石塑性变形机制转制约条件，并指出这类研究为分析中，下地壳或中，深变质岩区岩石变形环境开辟了新的途径和线索。  相似文献   

准噶尔西北部塔尔巴哈台组早石炭世植物和遗迹化石的发现及其古地理意义*   总被引：1，自引：0，他引：1       下载免费PDF全文

纵瑞文  范若颖  赵龙  龚一鸣  王国灿 《古地理学报》2014,16(3):319-334

首次在准噶尔西北部塔尔巴哈台组上部发现了早石炭世维宪期植物化石 Archaeocalamites scrobiculatus,Sublepidodendron grabaui,S. mirabile,S. cf. mirabile,Sublepidodendron sp., Lepidodendropsis sp., Mesocalamites sp., Sigillaria sp., Rhodiopteridium?sp.,Knorria sp.,证实了该组的时代可延续到早石炭世。根据研究区塔尔巴哈台组和上覆黑山头组的生物组合面貌及二者的接触关系,论证了塔尔巴哈台组顶部和黑山头组在准噶尔西北部具有明显的穿时性,前者从杜内期延续到维宪期,后者从杜内期延续到谢尔普霍夫期。与植物化石共同保存的深水相遗迹化石指示了塔尔巴哈台地区在早石炭世早中期为半深海-深海沉积环境,不同于东部吉木乃地区同期的滨浅海沉积环境,说明准噶尔西北部在早石炭世存在着不同的沉积体系。北疆地区早石炭世广泛的海侵活动以及额尔齐斯-斋桑洋向南侧哈萨克斯坦板块俯冲是造成这种沉积差异的主控因素,同时也造成了塔尔巴哈台组和黑山头组在区域上具穿时性。  相似文献   

TM50在跨断层水平位移(短程)测量中的应用   总被引：1，自引：0，他引：1       下载免费PDF全文

易天阳  王伟力  温军军  卓如峰 《地震工程学报》2016,38(6):1010-1015

对于短程跨断层水平位移测量,采用高精度光电测距仪是较好的选择,就目前的测量技术与作业方法而言,徕卡测量机器人TM50无论在测量精度还是作业速度上都具有很好的表现。通过两个跨断层场地的实例展现了TM50在跨断层水平位移测量中的应用,并对多周期实例数据进行了比较分析。  相似文献   

2592~1225aB.P.湖北神农架石笋氧同位素记录及区域气候意义     

张春霞  张茂恒  李偏  孔兴功  朱正坤  姜修洋  汪永进 《地理科学》2010,30(6):950-954

选择处于典型季风区中国内部湖北神农架地区青天洞一支具有连续清晰年纹层发育的石笋样品(QT6),通过精确的年纹层计数,结合高精度²³⁰Th年龄,建立2 592~1 225 a B.P.期间长达1 367 a的石笋δ¹⁸O时间序列。石笋δ¹⁸O记录的17个持续时间在80 a左右的峰谷旋回,与格陵兰冰芯δ¹⁸O记录具有非常好的一一对应关系,说明在年代际尺度上石笋δ¹⁸O同样能反映区域性气候变化,可能的机制是北高纬温度的变化通过大气传输影响热带辐合带(ITCZ)的迁移,从而影响东亚季风的强弱变化。  相似文献   

东昆仑造山带前陆盆地的叠加褶皱及其变形机制   总被引：4，自引：1，他引：3       下载免费PDF全文

侯光久  王国灿  张克信  陈能松  朱云海  拜永山 《地球科学》1999,24(2):42

在东昆仑造山带的三叠纪洪水川群复理石岩系中,发育着两组斜歪－倒转褶皱：一组轴迹方向为北西向,与造山带主体构造线近一致;另一组为新发现的北东向,与造山带主体构造线近垂直,形成叠加褶皱．每一组褶皱均是压扁、纯剪切、纯剪切＋简单剪切三种变形机制的产物．北西向褶皱轴面的南西倒和北东向褶皱轴面的北西倒,与国内外典型的前陆盆地中的褶皱形态不尽相同,反映了动力基础是板块碰撞之后的近于垂直的北东及北西方向挤压应力相继作用下形成的叠加褶皱．北东向褶皱的发现,揭示了造山带中构造应力场的转换．  相似文献   

A New Understanding on the Emplacement of Ophiolitic Mélanges and its Tectonic Significance: Insights from the Structural Analysis of the Remnant Oceanic Basin-Type Ophiolitic Mélanges     

WANG Guocan  ZHANG Pan 《《地质学报》英文版》2020,94(Z1):60-62

  相似文献   

Late Neogene Mountain Building of Eastern Kunlun Orogen: Constrained by DEM Analysis     

Wang An  Wang Guocan  Zhang Kexin  Xiang Shuyuan  Li Dewei  Liu Demin 《中国地质大学学报(英文版)》2009,20(2)

Topography, as a net result of the dynamic interaction between endogenesis and exogenesis, holds immense information on tectonic uplift, surface erosion and thus mountain building. The eastern Kunlun (昆仑) orogen, which experienced significant Late Neogene tectonic uplift and is located in an arid environment, is advantageous for morphotectonlc analysis based on well-preserved tectonic landforms. The digital elevation model (DEM) analysis was carried out for the central segment of the eastern Kunlun orogen based on shuttle radar topography mission (SRTM) data. River longitudinal profile analysis indicates that major rivers across the orogen are characterized by high river gradient indexes and intensive tectonic uplift. Differential uplift was also identified in swath-topography analysis in the studied area, which can be divided into three major tectonic-geomorphic units by orogenicstrike-parallel faults. It is indicated that the most active region is located to the south of the Xidatan (西大滩) fault with significant differential uplift. Another identified fault with differential uplift is the Middle Kuninn fault; however, the timing of which is suggested to be much older than that of the Xidatan fault. These analyses are eoneordantly supported by both field survey and studies of thermochronology, which in turn indicates that the DEM analysis bears great potential in morphotectonic analysis.  相似文献