新疆普鲁一带下古生界地层岩石组合及构造环境   总被引：1，自引：0，他引：1  

王洁明  肖丽君 《陕西地质》2003,21(1):52-60

西昆仑地块是西昆仑造山带的重要组成部分，南北边界分别为康西瓦—苏巴什华力西期缝合带和库地—其曼于特加里东期缝合带。新疆普鲁一带下古生界地层，分布于西昆仑地块东部，主要由一套海相火山岩和浅海陆棚相细碎屑岩组成，并遭受了绿片岩相的变质作用。通过1：25万《于田一伯力克幅)区调工作，将新疆普鲁一带下古生界地层厘定为下古生界奥陶—志留系，认为形成的大地构造环境为大陆活动边缘。  相似文献   

辽西北票(金-羊)盆地中生代砂岩碎屑组分对区域构造演化的响应   总被引：2，自引：1，他引：2  

闫义  林舸  李自安  贺世杰  徐政语 《沉积学报》2003,21(3):441-447

根据北票 (金-羊 )盆地中生界砂岩碎屑组分分析,综合区域构造演化背景、盆地沉积充填序列及砾岩特征,对盆地中生代物源及构造演化进行了示踪 :晚三叠世为盆地构造活化的起始阶段,盆地物源应主要来自周缘隆升蚀源区的前中生代碎屑沉积物;早侏罗世辽西地区发生了明显的差异升降,北票 (金-羊 )盆地相对伸展陷落,盆地范围有所扩大;晚侏罗世北西-南东向逆冲推覆作用成为盆地的主要控制因素,北票 (金-羊 )盆地具有明显前陆盆地特征,盆地西缘太古代变质岩系出露剥蚀而成为盆地的主要物源之一;早白垩世辽西地区发生构造反转,北票 (金-羊 )盆地相对萎缩。Dickinson模型并不完全适用于辽西地区。  相似文献   

冀北地区金矿床He、Ar、Pb同位素组成及其成矿物质来源   总被引：13，自引：0，他引：13  

王宝德  牛树银  孙爱群  李红阳 《地球化学》2003,32(2):181-187

成矿物质来源一直是成矿理论研究和找矿实践的焦点问题。选择了冀北地区3个幔枝构造金矿集中区11个金矿床黄铁矿及部分围岩进行了He、Ar同位素测定。研究表明,冀北地区主要金矿的3He/4He的值域为(0.93～7.30)×10-6,平均3.55×10-6;R/Ra=0.66～4.93,平均2.53;40Ar/36Ar=426～2073,40Ar平均为8.20×10-7cm3/g,4He/40Ar平均为2.17。矿区外围片麻岩和花岗岩的3He/4He值仅为(0.001～0.55)×10-6,反映来源上有明显差别。3He和4He在He同位素浓度图上落于地幔区附近。64个Pb同位素数据表现为矿质以幔源为主,确有部分壳源物质加入。研究认为,本区成矿物质应源于地球深部,随地幔柱多级演化,深部成矿流体由地球深部迁移到浅部,期间不可避免地存在壳幔流体的混合作用,故其值域往往界于地幔和地壳之间。  相似文献   

Optimization of the Sampling Technique for the Determination of Dissolved Hydrogen in Groundwater     

Axel Heimann  Silke Marczinek  Karin Kloosb  Stefan Peiffer 《洁净——土壤、空气、水》2003,31(6):491-500

In this study a field‐sampling technique for dissolved hydrogen (H₂) in groundwater will be presented which allows the transport of gaseous samples into the laboratory for further analysis. The method consists of transferring the headspace trapped in a gas‐sampling bulb which is continuously purged by groundwater into previously evacuated vials using a gas‐tight syringe. Three transfer steps with preceding evacuation of the vial led to a H₂‐recovery of 100 % in laboratory experiments. The method has been applied to determine H₂ concentrations in an aquifer contaminated with chlorinated solvents. Tests concerning the effect of different pumping techniques on H₂ concentrations revealed that most reliable values were obtained with a bladder pump, while an electrically driven submersible pump generated considerable amounts of hydrogen due to electrochemical interactions with the sampled water. Concentrations of dissolved hydrogen in field and laboratory samples were about two orders of magnitude higher when sampling was performed with the electrically driven submersible pump compared to sampling with the bladder pump and a peristaltic pump. Lab experiments with a Plexiglas reservoir to produce H₂‐enriched water were used to study the effect of two tubing materials (PVC, polyamide) on H₂ losses. PVC tubing turned out to allow transfer of H₂‐enriched water over 25 m without significant losses, while PA‐tubing was not suitable for sampling of H₂.  相似文献   

时频测控技术的发展   总被引：11，自引：1，他引：11  

周渭  王海 《时间频率学报》2003,26(2):87-95

目前，在所有的物理量中时间与频率标准的物理实现具有最高的准确度和稳定度，它们的发展不但在计量技术中，而且在几乎整个高科技领域中起着十分重要的作用。这方面的发展一直受到发达国家的高度重视。根据近年来与国外同行的技术交流和了解的情况，对时频测控技术的发展和影响等作了介绍。  相似文献   

Compositional Geometry and Mass Conservation   总被引：1，自引：0，他引：1  

Robert F. Shurtz 《Mathematical Geology》2003,35(8):927-937

A geometrical structure is imposed on compositional data by physical and chemical laws, principally mass conservation. Therefore, statistical or mathematical investigation of possible relations between data values and such laws must be consistent with this structure. This demands that geometrical concepts, such as points that specify both mass and composition in linear space, and lines in projective space that specify composition only, be clearly defined and consistent with mass conservation. Mass thus becomes the norm in composition space in place of the Euclidean norm of ordinary space. Coordinate transformations inconsistent with this geometry are accordingly unnatural and misleading. They are also unnecessary because correlation arising from the constant mass presents no unusual difficulty in the analysis of the underlying quadratic form.  相似文献   

Tectonic controls on metamorphism, partial melting, and intrusion: timing and duration of regional metamorphism and magmatism in the Ni de Massif, Turkey     

Donna L. Whitney  Christian Teyssier  Annia K. Fayon  Michael A. Hamilton  Matt Heizler 《Tectonophysics》2003,376(1-2):37-60

Mafic high-pressure granulite, eclogite and pyroxenite xenoliths have been collected from a Mesozoic volcaniclastic diatreme in Xinyang, near south margin of the Sino-Korean Craton (SKC). The high-pressure granulite xenoliths are mainly composed of fine-grained granoblasts of Grt+Cpx+Pl+Hbl±Kfs±Q±Ilm with relict porphyritic mineral assemblage of Grt+Cpx±Pl±Rt. P–T estimation indicates that the granoblastic assemblage crystallized at 765–890 °C and 1.25–1.59 GPa, corresponding to crustal depths of ca. 41–52 km with a geotherm of 75–80 mW/m². Calculated seismic velocities (V_p) of high-pressure granulites range from 7.04 to 7.56 km/s and densities (D) from 3.05 to 3.30 g/cm³. These high-pressure granulite xenoliths have different petrographic and geochemical features from the Archean mafic granulites. Elevated geotherm and petrographic evidence imply that the lithosphere of this craton was thermally disturbed in the Mesozoic prior to eruption of the host diatreme. These samples have sub-alkaline basaltic compositions, equivalent to olivine– and quartz–tholeiite. REE patterns are flat to variably LREE-enriched (La_N/Yb_N=0.98–9.47) without Eu anomaly (Eu/Eu*=0.95–1.11). They possess 48–127 ppm Ni and 2–20 ppm Nb with Nb/U and La/Nb ratios of 13–54 and 0.93–4.75, respectively, suggesting that these high-pressure granulites may be products of mantle-derived magma underplated and contaminated at the base of the lower crust. This study also implies that up to 10 km Mesozoic lowermost crust was delaminated prior to eruption of the Cenozoic basalts on the craton.  相似文献   

THE OPTIMAL GRAINSIZE COMPOSITION OF SUSPENDED SEDIMENT OF HYPERCONCENTRATED FLOW IN THE MIDDLE YELLOW RIVER     

XU Jiongxin Professor  Institute of Geography  Chinese Academy of Sciences  Beijing  China 《国际泥沙研究》1997,(3)

LINTRODUCTIONThetributariesofmiddleYellowRiverarefamousintheworldforthehighestsuspendedsedimentconcentrationandsedimentyield.Forexample,atWenjiachuanstationofKuyeheRiverthemeasuredhighestsuspendedconcentrationis1700kg/m',andthemeanannualsedimentyieldis25000t/(kln'.a).Theformationofhyperconcentratedflowsandtheirinfluenceonerosionprocessesareofgreatimportancenotonlyfromatheoreticalpointofviewbutalsoforpracticalpurposes.Therefore,scientistsfromChinaandallovertheworldhavedrawntheirintensio…  相似文献   

云南老王寨金矿区煌斑岩的源区成分模拟   总被引：2，自引：1，他引：2  

黄智龙  王联魁 《矿物学报》1997,17(3):316-320

本文在总结云南老王寨金矿区煌斑岩的主要元素、过渡元素、亲石元素、稀土元素和同位素地球化学特征的基础上．利用岩石学混合计算方法对其源区成分进行了模拟，进而讨论了矿区这类岩石的成因。地球化学和模拟计算均表明，老王寨金矿区煌斑岩来源于交代富集地幔，板块俯冲（印度板块向欧亚板块俯冲）富含ALK、LREE及不相容元素的海底沉积物被带入地幔脱水形成的流体是引起本区地幔交代作用的主要因素。  相似文献   

湘西沃溪金锑钨矿床中石英的矿物学研究          下载免费PDF全文

邵靖邦  樊江  王濮  翁玲宝  陈代璋 《岩石矿物学杂志》1997,(1)

通过对矿床中不同世代及不同地质产状石英的颜色、形态、物理性质、化学成分、晶胞参数、结晶度的研究及Ｘ射线分析及红外光谱、电子顺磁共振谱等近代物理分析方法的测试，找出了矿化石英与非矿化石英及不同类型矿化石英的标型特征，这些标型特征具有重要的找矿勘探意义  相似文献