Radar observations of prevailing winds and waves in the Southern Hemisphere mesosphere and lower thermosphere     

A. Phillips  R. A. Vincent 《Pure and Applied Geophysics》1989,130(2-3):303-318

HF radar stations (utilizing the spaced-antenna partial-reflection technique) located at Adelaide (35°S, 138°E) and Mawson Station (67°S, 63°E) have observed horizontal mesospheric winds continuously since mid-1984. Observations in the period 1984–87 are compared with the Northern Hemisphere [latitude conjugate] stations of Kyoto (35°N, 136°E) and Poker Flat (65°N, 147°W), and with satellite-derived circulation models. Particular reference is made to the equinoctial changeovers in zonal flow and to the temporal and altitude variations in the planetary wave activity at Mawson and Adelaide.  相似文献   

苏鲁超高压变质地体及其成因解释   总被引：29，自引：7，他引：29  

张儒媛  从柏林 《岩石学报》1993,9(3):211-226

  相似文献   

Southern margin of the Variscan belt: the north-western Gondwana mobile zone (eastern Morocco and Northern Algeria)     

A. Piqué  G. Bossière  J. -P. Bouillin  A. Chalouan  Ch. Hoepffner 《International Journal of Earth Sciences》1993,82(3):432-439

Stratigraphic and structural correlations between the Palaeozoic massifs of eastern Morocco and northern Algeria allow three tectonic domains to be distinguished: (1) The cratonic zone, i.e. the West African platform which remained outside the Variscan chain and its peripherical margin (Moroccan Anti-Atlas and Algerian Ougarta); (2) a WSW-ENE trending zone, over 1500 km from Marrakech to Kabylia and Calabria (in their assumed Palaeozoic location). — This zone was characterized during the Late Palaeozoic by a continuous instability indicated by the development of successive turbiditic basins and a major orogeny at the Devonian-Carboniferous boundary; and (3) central and western Morocco, which corresponds to the external zones of the European Hercynides.The Marrakech-Kabylia zone separates the Variscan domain from the stable and undeformed West African craton. During Early Palaeozoic times it began as an extensive or transtensive zone. It has been deformed by the Late Devonian orogeny and by Carboniferous and Permian reactivation. The zone represents the southern limit of the Hercynian chain and is distinguished by its transcurrent regime throughout the Late Palaeozoic. Correspondence to: A. Piqué  相似文献   

佳木斯地体深部构造特征     

张世红  施央申 《大地构造与成矿学》1993,17(1):93-101

本文通过重磁资料的数据处理和反演、天然地震震源的统计以及深断裂与火山活动关系的研究提出:佳木斯地体与两侧的造山带有着截然不同的地壳物质组成和构造类型,晚白垩世以来,其深部构造活动性较两侧更强。  相似文献   

耦合海气动力学短期变率的数值研究   总被引：1，自引：1，他引：1  

罗艳  姜达雍  刘屹岷 《热带气象学报》1994,10(2):97-106

为了探索全球性气候变化的年际变率，研制了一个复盖热带太平洋区域的耦合海气模式，并用来模拟ＥＮＳＯ变率的主要特征。数值试验结果与实况比较表明，对１９８２／１９８３年厄尔尼诺事件的主要特征模拟良好。基本结论是要考虑好关键要素和关键过程，即：平均风场和平均海温场；风和海温场的年循环；海洋表面层；三维海温平流；大气（水平方向）水汽辐合效应。  相似文献   

大别山前寒武纪变质地体基本组成   总被引：5，自引：0，他引：5  

桑隆康  游振东 《地质论评》1994,40(3):265-273

本文以新城－圻春断裂为界将大别山前寒武纪变质地体划分为华北陆块南缘和场子陆块北缘两个次级变质地体，两个次级地体不仅在地球物理，构造变形方面明显不同，而且在物质成分上有显著差异，它们有各自独立的变质地层系统，遭受了不同类型的变质作用，有完全不同的岩浆活动图象，上述差异均可指示华北，扬子两古陆碰掸对接时扬子陆块北缘向北俯冲至华北陆块南缘之下，这可能包括两次合作用，从元古代开始至中生代最终结束的长期复杂  相似文献   

The Zoulang Nanshan Caledonian Subduct ion Complex in the Northern Qilian Mountains and Its Dynamics   总被引：1，自引：0，他引：1  

Xu Zhiqin  Xu Huifen  Zhang Jianxin  Li Haibing  Zhu Zhizhi  Qu Jingchuan  Institute of Geology  Chinese Academy of Geological Sciences  BeijingChen Daizhang  Chen Jinlu  China University of Geosciences  Beijingand Yang KaichunNo. Q ilian Geological Party  Bureau of Geology  Mineral Resources of Q inghai Province  Q ilian County  Q inghai 《《地质学报》英文版》1994,68(3)

The front of the Zoulang Nanshan Caledonian volcanic island arc zone in the northern Qilian Mountains is a forearc accretionary terrane, composed of multiple accretionary volcanic island arcs, flysch accretionary wedges,high-pressure metamorphosed detachment zones and remnants of ophiolites. It resulted from the northeastward subduction of the Early Palaeozoic Qilan oceanic crust beneath the Alxa block. High-pressure metamorphism, which occurred during the subduction, progressed through three stages: the initial stage of medium T-high P,the main stage of temperature decrease and pressure increase, and the lag stage of pressure decrease and temperature increase. Finally the paper presents a retrotrench subduction dynamic model indicative of northward subduction of the central Qilian block and southward accretion of the Alxa block during the period of 450-500 Ma.  相似文献   

Mineral composition variation in Alpine Schist, Southern Alps, New Zealand: Implications for recrystallization and exhumation   总被引：1，自引：0，他引：1  

RodneyH.  Grapes Teruo  Watanabe 《Island Arc》1994,3(3):163-181

Abstract Compositional variation of silicates (plagioclase, K-feldspar, epidote, titanite, garnet, white mica, biotite, chlorite), ilmenite, carbonates (calcite, ankerite) and apatite, in quartzofeldspathic lithologies of the Alpine Schist, New Zealand, is discussed in terms of increasing metamorphic grade and possible isograd-producing reactions. The mineral data, in conjunction with geological considerations, are used to determine polychronous P-T arrays of an early high P/T event (c. 16°C/kb; 5°C/km) overprinted by a lower P/T event (c. 50°C/kb; 15°C/km) that provides an estimation of Mesozoic and Cenozoic exhumation of schist of 11 to 13 km and 19 to 22 km respectively. The effects of possible shear heating and recrystallization to form K-feldspar zone schist near the Alpine Fault is consistent with movement along a mid to lower crustal detachment surface during Cenozoic shortening, and near isothermal exhumation of the schists to form the Southern Alps.  相似文献   

湘南多金属矿床方解石形态及表面微形貌的研究     

李荣清 《湖南地质》1994,13(1):25-28

对湘南多金属成矿区方解石的研究表明，产于钨矿床中的方解石以层状晶体发育为特征，晶体形态主要为｛０００１｝和｛０１２｝＋｛１０１０｝，晶体表面具有菱形生长阶梯；产于铅锌矿床中的方解石一般不出现层解石，晶体形态主要为｛２１３１｝，｛０１１２｝＋｛１０１０｝和｛０００１｝＋｛１０１０｝＋｛０１１２｝，晶体表面平行纹发育；远矿正常灰岩内方解石晶体形态主要为｛４０４１｝。  相似文献   

Interpretation of aeromagnetic anomalies over part of Southeastern Nigeria using three-dimensional Hilbert transformation     

C. O. Ofoegbu  N. L. Mohan 《Pure and Applied Geophysics》1990,134(1):13-29

We present the results of the application of three-dimensional Hilbert transformation to the analysis of airborne total field magnetic anomalies over part of Southeastern Nigeria. This study not only substantiates the usefulness of 3-D Hilbert transforms in the interpretation of magnetic anomaly maps but also more clearly delineates the structural pattern of the area, of study. Results from the previous study are discussed in relation to the results of previous geological and geophysical studies of the area.  相似文献