福建锦城187Ma花岗岩的发现——对华南沿海早侏罗世构造演化的制约   总被引：7，自引：2，他引：5  

刘潜  于津海  苏斌  王勤  唐红峰  许海  崔翔 《岩石学报》2011,27(12):3575-3589

本文对福建沿海福清地区的锦城花岗岩和牛头尾花岗闪长岩进行了岩石地球化学、锆石U-Pb-Hf同位素分析.LA-ICP-MS锆石U-Pb定年结果显示锦城花岗岩的年龄为187±1Ma,为福建沿海首次发现的早侏罗世岩浆活动;牛头尾花岗岩形成时代为130±1Ma,代表燕山晚期(白垩纪)的一期岩浆活动.锦城花岗岩具有高5iO2、偏碱、高Fe2OT3等特征,为高钾钙碱性系列,岩石相对富集轻稀土,亏损Nb、Ta、Ti等高场强元素,富集Ba、Sr等大离子亲石元素,具高Rb/Sr( 1.31 ～ 1.93)比值及低Rb/Ba(0.26 ～0.29)、Eu/Eu*(0.30 ～0.56)、La/Yb(5.69 ～ 18.39),Sr/Y(2.24 ～2.29)比值,为典型的Ⅰ型花岗岩,且具有火山孤花岗岩的地球化学特征,很可能形成于与俯冲相关的构造背景.牛头尾花岗岩相比锦城花岗岩低SiO2,贫钾,而富镁、钙,属于花岗闪长岩.其更亏损Nb、Ta及富集Ba、Sr,具较低Rb/Sr(0.27)、Rb/Ba(0.09)比值和较高的Eu/Eu*(0.98)、La/Yb( 16.87),Sr/Y( 19.08)比值,同样为具有弧特征的钙碱性Ⅰ型花岗岩,也形成于与大洋俯冲有关的构造背景.锦城花岗岩和年头尾花岗闪长岩具有相似的锆石Hf同位素组成,εHf(t)分别为2.18～4.73和1.25 ～4.15,tDMC均为～ 1.0Ga,表明二者起源于相同的新元古代新生地壳.结合已有的资料,本次研究发现锦城花岗岩与南岭地区同时代岩浆岩( 194 ～ 172Ma)在成因上有密切的联系,暗示古太平洋板决的俯冲很可能自早侏罗世开始.这样,华南古特提斯构造域向古太平洋构造域的转换很可能发生在早侏罗世之前,大致在205 ～ 190Ma期间.  相似文献   

卡姆斯特煤田侏罗系八道湾组地层层序及聚煤特征          下载免费PDF全文

吴天伟田继军  木合塔尔·扎日 陈 斌 马 帅 柳 磊 《中国地质》2011,38(5):1312-1323

综合利用卡姆斯特煤田钻孔测井、野外露头及古生物化石等资料,应用经典层序地层学基本理论和方法,对卡姆斯特煤田八道湾组进行了层序地层划分,共识别出SQ1和SQ2两个三级层序,并根据地层叠置样式、沉积旋回特征细分为6个体系域。通过沉积基础图件、沉积环境的分析明确了研究区八道湾组沉积演化主要受古地形起伏、古气候条件等古地理因素的综合影响。确定研究区内目的层段主要在高位和低位时期聚煤,湖侵时期不利于聚煤。通过详细研究卡姆斯特煤田八道湾组的沉积环境和聚煤特征,为今后寻找和开发卡姆斯特地区煤炭资源提供地质依据。  相似文献   

青海省天峻县木里煤田聚乎更矿区构造轮廓和地层格架     

文怀军  邵龙义  李永红  鲁静  张少林  王文龙  黄曼 《中国区域地质》2011,(12):1823-1828

木里煤田聚乎更矿区是全球陆上中纬度、高海拔冻土带天然气水合物的发现地,也是当前青藏高原地质研究的热点地区之一。依据近年来的煤炭地质勘查资料,对聚乎更矿区的构造轮廓、含煤地层、沉积相和聚煤作用进行深入分析．认为聚乎更矿区位于祁连坳褶带西段,受大通山北缘和托莱山南缘对冲断裂组的制约,构造线总体方向为北西一南东向,构造轮廓表现为南北2个向斜,其中北向斜的煤炭赋存条件优于南向斜。聚乎更矿区含煤地层为中侏罗统木里组和江仓纽。主要可采煤层赋存于木里组上段,聚煤作用主要发生于木里组沉积期的辫状河淤浅之后发育的泥炭沼泽和湖泊、水下三角洲淤浅而发育的泥炭沼泽。  相似文献   

江苏江都市大桥镇晚更新世晚期—全新世有孔虫动物群的发现及其地质意义     

韦一  韩芳  魏乃颐  于庆文  张智勇  张克信 《地质科技情报》2011,30(3):41-47

在江苏省江都市ZKA4钻孔孔深4.0～42.6 m岩心段中发现有孔虫化石,鉴定识别出有孔虫38属56种,其中9个未定种,根据有孔虫动物群在钻孔剖面上的分布规律,建立了 3个有孔虫化石组合,自上而下为:Ammonia beccarii Linne)vars.-Orbulina universa组合,Ammonia bec...  相似文献   

西藏冈底斯带中南部与俯冲有关的早侏罗世花岗闪长岩:锆石U-Pb年代学及地球化学证据   总被引：1，自引：0，他引：1  

陈炜  马昌前  宋志强  龙桃成  夏天齐  蔡立元  王彤 《地质科技情报》2011,30(6):1-12

肖打松多花岗闪长岩位于西藏冈底斯花岗岩带中段以南,主要岩石类型有:细中粒黑云母(角闪石)花岗闪长岩、细中粒含斑黑云母(角闪石)花岗闪长岩、细中粒斑状黑云母(角闪石)花岗闪长岩,岩石具钙碱性特征,w(SiO2)=61.58％～72.16％,w(K2O)/w(Na2O) =0.64～1.15,相对富钠,A/CNK=1.25...  相似文献   

塔里木盆地侏罗系层序地层特征     

刘辰生  郭建华 《地质科技情报》2011,30(5):5-11

通过野外露头资料、测井资料和地震资料分析,塔里木盆地侏罗系可识别出8个层序边界,除层序边界JSB6和JSB7为Ⅱ型外,其他均为Ⅰ型.层序界面上下常表现为沉积相突变或地层缺失.根据8个三级层序边界可识别出7个三级层序,即JSQ1～JSQ7,各层序在盆地内的分布却不均匀.JSQ1和JSQ2层序分布在阿克库勒凸起的于奇地区、...  相似文献   

Description and Phylogenetic Position of Dinosaur Eggshells from the Luanchuan Area of Western Henan Province, China     

Kohei TANAKA  Lü Junchang  Yoshitsugu KOBAYASHI  Darla K. ZELENITSKY  XU Li  JIA Songhai  QIN Shuang  TANG Min’an 《《地质学报》英文版》2011,85(1):66-74

Here, we examine 145 dinosaur eggshells from a new fossil locality in the Qiupa Formation (Upper Cretaceous) of the Luanchuan area in western Henan Province, China. The eggshells display elongatoolithid macro- and microstructures, including ridges and nodes on the outer surface, two ultrastructural layers, and an undulatory boundary between the mammillary and continuous layers. A phylogenic analysis shows that the Luanchuan eggshells belong to the ooclade Elongatoolithidae. Within Elongatoolithidae, the thickness ratio of the mammillary layer to the entire eggshell, and the porosity of the Luanchuan eggshells are comparable to the oogenera Macroolithus and Elongatoolithus. There is no direct evidence for the taxonomic identity of the Luanchuan eggshells; however, they were likely laid by oviraptorids based on their phylogenetic position and their similarities with known oviraptorid eggs.  相似文献   

U-Pb Dating of Volcanic Rocks and Granites along the Wuyishan Belt: Constraints on Timing of Late Mesozoic Tectonic Events in Southeast China     

XU Xianbing  ZHANG Yueqiao  JIA Dong  SHU Liangshu 《《地质学报》英文版》2011,85(1):130-144

Five volcanic rock samples and two granite samples taken from the volcanic basins in western Fujian and southern Jiangxi were dated by using the zircon laser albation-inductively coupled plasma mass spectrometry U-Pb method. Together with previously dated ages, the dates obtained provide important constraints on the timing of late Mesozoic tectonic events in SE China. The volcanic rock samples yield ages of 183.1±3.5 Ma, ca. 141 Ma to 135.8±1.1 Ma, 100.4±1.5 to 97.6±1.1 Ma, confirming three episodes of late Mesozoic volcanic activities, which peaked at 180±5 Ma, 140±5 Ma and 100±5 Ma, respectively, along the Wuyishan belt. Moreover, based on field investigations of these volcano-sedimentary basins, we have recognized two compressional tectonic events along this belt. The early one was characterized by Upper Triassic to Middle Jurassic NNE-trending folds that were intruded by late Jurassic granites; and the late one caused the Lower Cretaceous volcano-sedimentary layer to be tilted. The dated age 152.9±1.4 Ma of the granitic samples from the Hetian granitic pluton in the Changting Basin and that from the Baishiding granitic pluton, 100.2±1.8 Ma, in the Jianning Basin, give the upper boundaries of these two tectonic events respectively. Hence, the late Mesozoic tectonic evolution of SE China was alternated between extension and compression.  相似文献   

A New Darwinopterid Pterosaur from the Middle Jurassic of Western Liaoning, Northeastern China and its Ecological Implications   总被引：2，自引：0，他引：2  

Lü Junchang  XU Li  CHANG Huali  ZHANG Xingliao 《《地质学报》英文版》2011,85(3):507-514

A new species of Darwinopterus, D. robustodens sp. nov. is described and named. Based on the new specimen, the diagnostic characters of Darwinopterus are amended and include: rostral dentition composed of well-spaced, spike-like teeth; the longest teeth are confined to the anterior half of the tooth row; tooth alveoli have raised margins; nasoantorbital fenestra confluent; inclined quadrate; elongate cervical vertebrae with low neural spine and reduced or absent ribs; long tail of more than 20 caudals partially enclosed by filiform extensions of the pre- and postzygapophyses; short metacarpus less than 60 per cent length of humerus, fifth toe with two elongate phalanges and curved second pedal phalanx of the fifth toe with the angle between the proximal and distal segments about 130 degrees. The complete specimen of the new pterosaur D. robustodens sp. nov. provides much more osteological information. The differences in tooth morphologies between Darwinopterus modularis and D. robustodens sp. nov. suggest that they filled different ecological niches. The hard integument-bearing Coleoptera may have been the main food source of Darwinopterus robustodens.  相似文献   

Changes of Late Mesozoic Tectonic Regimes around the Ordos Basin (North China) and their Geodynamic Implications   总被引：4，自引：0，他引：4  

ZHANG Yueqiao  SHI Wei  DONG Shuwen 《《地质学报》英文版》2011,85(6):1254-1276

A synthesis is given in this paper on late Mesozoic deformation pattern in the zones around the Ordos Basin based on lithostratigraphic and structural analyses. A relative chronology of the late Mesozoic tectonic stress evolution was established from the field analyses of fault kinematics and constrained by stratigraphic contact relationships. The results show alternation of tectonic compressional and extensional regimes. The Ordos Basin and its surroundings were in weak N-S to NNE-SSW extension during the Early to Middle Jurassic, which reactivated E-W-trending basement fractures. The tectonic regime changed to a multi-directional compressional one during the Late Jurassic, which resulted in crustal shortening deformation along the marginal zones of the Ordos Basin. Then it changed to an extensional one during the Early Cretaceous, which rifted the western, northwestern and southeastern margins of the Ordos Basin. A NW-SE compression occurred during the Late Cretaceous and caused the termination of sedimentation and uplift of the Ordos Basin. This phased evolution of the late Mesozoic tectonic stress regimes and associated deformation pattern around the Ordos Basin best records the changes in regional geodynamic settings in East Asia, from the Early to Middle Jurassic post-orogenic extension following the Triassic collision between the North and South China Blocks, to the Late Jurassic multi-directional compressions produced by synchronous convergence of the three plates (the Siberian Plate to the north, Paleo-Pacific Plate to the east and Lhasa Block to the west) towards the East Asian continent. Early Cretaceous extension might be the response to collapse and lithospheric thinning of the North China Craton.  相似文献