Computation of seismograms and atmospheric oscillations by normal-mode summation for a spherical earth model with realistic atmosphere   总被引：2，自引：0，他引：2  

Philippe Lognonné  Eric Clévédé  & Hiroo Kanamori 《Geophysical Journal International》1998,135(2):388-406

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河北平泉光头山碱性花岗岩的时代、Nd-Sr同位素特征及其对华北早中生代壳幔相互作用的意义   总被引：20，自引：13，他引：20  

韩宝福  加加美宽雄  李惠民 《岩石学报》2004,20(6):1375-1388

光头山碱性花岗岩产出在华北北部的前寒武纪基底变质岩系之中,造岩矿物组合为石英 碱性长石 纳铁闪石 霓辉石 钠铁非石±星叶石,副矿物有锆石、钛铁矿、硅钛铈铁矿等。晚期的伟晶岩囊状体由颗粒粗大的石英、碱性长石和纳铁闪石等组成,全岩Rb-Sr等时线年龄为T=200±16Ma,(~(87)Sr/~(86)Sr)_i=0.705±0.008,MSWD=11.2,代表冷却年龄,单颗粒锆石U-Pb谐和年龄为220±1Ma,代表岩体侵位时代。光头山碱性花岗岩以A/CNK<1和A/NK<1,Al_2O_3、MgO、CaO和Ba、Sr含量低,全碱含量、MnO和Rb、Ga等含量高,负Eu异常特别显著等为特征。矿物学和地球化学完全符合A型花岗岩的特征。光头山碱性花岗岩是华北地区早中生代后造山环境下岩浆活动的产物。光头山碱性花岗岩的ε_(Nd)(T=220Ma)平均值为-8.9,明显高于华北前寒武纪下地壳岩石的范围,而冀北地区前寒武纪高压麻粒岩地体虽具有大陆地幔的特征,但未经历过部分重熔,表明至少前寒武纪下地壳不可能是岩浆主要的或唯一的来源同样,现今华北下地壳由于时代较新,也不可能成为岩浆的源岩,对比时代相近的超镁铁岩和煌斑岩的Nd同位素特征,推测最可能的源区是1.8～1.9Ga形成的富集的岩石圈地幔。光头山碱性花岗岩和华北北缘早中生代侵入岩带规模很大,以富集地慢来源的岩浆为主,反映了当时的岩浆活动已经具有相当的规模和强度,如果130Ma前后中国东部大规模岩浆活动之时,是岩石圈减薄已经达到最大程度之际,那么,此前一定时间段内的幔源岩浆活动都有可能与岩石圈减薄从开始到鼎盛的过程有关,所以,华北北缘早中生代岩浆活动可能是华北中生代岩石圈减薄过程早期阶段的产物。与岩石圈减薄过程有关的早中生代岩浆活动还在中国东北地区东部和阿拉善北部形成了后造山A型花岗岩。与岩石圈减薄过程相关的早中生代侵入岩在一定范围内的带状分布,表明当时岩石圈减薄过程可能并没有涉及到整个中国东部地区只有到了侏罗纪-白垩纪,岩石圈减薄过程才在更大的区域内广泛发生。所以说,中国东部中新生代岩石圈减薄过程是在时间上从早中生代就已经开始、在空间上从华北北缘-中国东北地区东部开始向外逐渐扩展的一个深部过程。这个深部过程对应的地表表现是,先在华北北缘和中国东北东部地区形成规模很大的早中生代侵入岩带。而后,当岩石圈减薄过程扩展到整个中国东部时,岩浆活动才达到鼎盛时期,这可能就是中国东部侏罗纪-白垩纪大规模岩浆活动的深部原因所在。而以富集地幔源区为主的岩浆活动还导致了华北北缘地壳垂向生长。  相似文献   

Day care services and activity patterns of women in Japan     

Hiroo Kamiya 《GeoJournal》1999,48(3):207-215

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闽粤晚白垩世古地磁学研究   总被引：1，自引：0，他引：1       下载免费PDF全文

森永速男  井口博夫  宫田隆夫 《地球科学》1999,24(2):142-144

在福建沙县至上杭、广东兴宁至河源上白垩统采集古地磁学定向样品３９０个（３９个采点）,进行了古地磁学研究,研究表明,闽粤两地的晚白垩世地磁学数据具有廊的重合性,福建：古地磁偏角１１．７°,地磁倾角４２．９°,地磁极位置北纬７９．４°,东径２１０．３°;广东;古地磁偏角１０．７°,古地磁倾角４４．０°,古地磁有位置北纬８０．１°,东径１９３．４°,该古寺磁学数据反映了中国华南地区自晚白垩世至今曾经厍过  相似文献   

Model Space Exploration for Determining Landslide Source History from Long-Period Seismic Data     

Juan Zhao  Laurent Moretti  Anne Mangeney  Eléonore Stutzmann  Hiroo Kanamori  Yann Capdeville  Eliza S. Calder  Clément Hibert  Patrick J. Smith  Paul Cole  Anne LeFriant 《Pure and Applied Geophysics》2015,172(2):389-413

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Paleomagnetism of Cretaceous Red beds from Eastern Part of South China Block     

Hayao Morinaga  Hiroyuki Kashimura 《中国地质大学学报(英文版)》1999,10(3)

INTRODUCTIONCollisionofIndiawithAsiaappearstohavebroughtaboutlargetectonicdeformationofAsia,especiallyEastAsia(Tapponnieretal.,1986).Post-Cretaceousdeformation(translationand/orrotation)ofSimaoandIndochinablocks,whicharelocatedatthesouthernsideofRedRiverfault(RRF),hasbeenreportedfromCretaceouspaleomagneticin-vestigations(Yangetal.,l995;HuangandOpdyke,l993IYangandBesse,1993).AlsoinSouthChinablock(SCB)locatedatnorthsideoftheRRF,localdeformationofsomeregionsneartheRRFhasbeendocum…  相似文献   

Determination of Selenium in Marine Aquatic Products by Hydride Generation-atomic Fluorescence Spectrometry （HG-AFS）     

ZHANG Zhaohui GAO Xin Tashiro Yuri Hiroo Ogawa 《中国海洋大学学报(英文版)》2005,4(3):252-256

A method for the analysis of selenium in marine aquatic products by HG-AFS has been investigated. The method is based on the reduction of inorganic selenium to volatile SeH2 which is bubbled out by carrier gas of pure argon, and then swept to Ar-H2 flame quarts atomizer to measure its fluorescence intensity. The hydride generation, transportation, atomization and some instrumental parameters were studied by a kind of orthogonal design. The optimum conditions selected are as follows： reactive acidity, 20% HC1; the amount of NaBH4, 4.9mL; gas flow of argon, 600mLmin^-1; atomizing temperature, 200 ℃ ; negative high voltage, - 300V; light current, 100 mA; integral time, 7s. The detection limit of the presented method is 0.072μgL^-1 for selenium. The calibration curve shows a satisfactory line inthe concentration range from 0.000 to 1.000μgL^-1 Se. The recovery is 95.8%-102.2%.  相似文献   

从悬浮质和沉降质的观点描述中国云南湖泊的化学动态变化     

杉山雅人  佐佐木淳也  吉田宽郎  坂本充  宋学良  张子雄 《云南地理环境研究》2002,14(2):20-33

在对云南抚仙湖、星云湖和洱海3个高原湖怕进行地球化学和湖沼学调查，确定湖水中微粒的溶解浓度和化学成分，对沉降质和沉积物进行分析的基础上，对这些湖泊的化学动态变化进行了讨论。  相似文献   

Shear velocity and density of an attenuating earth     

Robert S. Hart  Don L. Anderson  Hiroo Kanamori 《Earth and Planetary Science Letters》1976,32(1):25-34

The dispersion that must accompany absorption is taken into account in many recent body-wave investigations but has been largely ignored in surface-wave and free-oscillation studies. In order to compare body-wave and free-oscillation data a correction must be made to travel times or periods to account for absorption-related physical dispersion. The correction depends on the frequency and Q of the data and can be as high as 1% which is much larger than the uncertainty of the raw data. Corrected toroidal mode data is inverted to obtain shear velocity and density versus depth. The average shear velocity in the upper 600 km is ～2% greater than obtained from the uncorrected data. The resulting shear-wave travel times oscillate about the Jeffreys-Bullen values with an average baseline of only +0.5 second. Thus, the discrepancy between body-wave and free-oscillation studies is eliminated.  相似文献   

Variation of seismic source parameters and stress drops within a descending slab and its implications in plate mechanics   总被引：1，自引：0，他引：1  

Wai-Ying Chung  Hiroo Kanamori 《Physics of the Earth and Planetary Interiors》1980,23(2):134-159

A least-squares searching technique has been developed to estimate the source dimensions of intermediate and deep focus earthquakes using azimuthal variations of body wave pulse-widths. With this method and also amplitude data, modes of rupture propagation, seismic moments, and stress drops of 17 intermediate and deep focus earthquakes in the Tonga-Kermadec region have been determined in order to investigate variations in source properties and the state of stress within the descending slab there. Three different modes of rupture; unilateral, bilateral, and circular faults, are compared and tested against observations. Results indicate that the unilateral fault is the best model for most of the earthquakes studied. Stress drops of the 17 events vary within a very large range, from 20 bar to about 4.6 kbar, and change significantly with depth. The magnitude of stress drops for depths between 220 and 430 km is very much higher than at shallower depths. This change in stress drop magnitude at about 220 km-depth seems to reflect a change in material properties both in the mantle and within the slab. Two regions of high stress drop are observed at depths of about 360 and 640 km. A relative minimum of stress drop is found at about 450–560 km where the earthquake frequency is particularly high. Earthquakes at the northern end to the Tonga arc, where the Benioff zone is laterally bent, show systematically higher stress drops than other events at comparable depths, but away from the bend. Also, events in regions of low seismicity appear to have higher stress drops than those in regions of high seismicity. The upper bound of seismic efficiency is found to decrease with depth, implying an increase of frictional force with depth at the earthquake source.  相似文献