A theory of spectral analysis based on the characteristic property of a linear dynamic system   总被引：3，自引：1，他引：2  

M. Kumazawa  Y. Imanishi  Y. Fukao  M. Furumoto  A. Yamamoto 《Geophysical Journal International》1990,101(3):613-630

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鲁西铜石中生代复式岩体岩石谱系单位划分及成因   总被引：1，自引：0，他引：1       下载免费PDF全文

孔令广  甘延景 《山东国土资源》2001,17(2):23-27

铜石岩体就位于燕山早期,有五次脉动侵入活动,相应地可建立五个单元,归并为铜石超单元;岩浆末期形成细晶岩、霏细岩,热膨胀形成隐爆角砾岩、侵入角砾岩及沉陷角砾岩等.铜石岩体具有花岗岩类高位深成复式岩体特征.  相似文献   

Humic Acid and Iron Chelation Modified Anode Improves the Electrochemical Performance of Marine Sediment Microbial Fuel Cell     

FU Yubin  CHEN Jiaqi  CHEN Yan  HUANG Xiang  LI Yang  ZHANG Huaijing  ZAI Xuerong 《中国海洋大学学报(英文版)》2022,21(2):388-394

Marine sediment microbial fuel cell(MSMFCs)can be utilized as a long lasting power source to drive small instruments to work for long time on ocean floor and its higher power has a significant meaning for practical application.Anode modification can greatly improve the performance of MSMFCs.Herein,humic acid(HA)and humic acid-iron ion complex(HA-Fe)were used to modify the anode for constructing a better MSMFCs.The results indicated that HA-Fe modified anode,better than HA modification,significantly improved the MSMFCs cell power output.The maximum power density of HA-Fe modified MSMFCs is 165.3 mW m?2,which are 6.5-folds of blank MSMFCs.The number of microorganisms on anode,redox activity,and relative kinetic activity were 1.8-,6.1-,and 13.1-folds of blank MSMFCs,respectively.The MSMFCs improvement would be attributed to the electron transfer media of HA and the valence conversion of Fe ions.A synergistic interaction between the naturally occurring HA and Fe ions on the anodic surface in marine sediments would make the modified anodes have‘renewable’characteristics,which is beneficial for the MSMFCs to maintain its long-term higher power.  相似文献   

ESR/U-series chronology of the Neanderthal occupation layers at Galería de las Estatuas (Sierra de Atapuerca,Spain)     

《Quaternary Geochronology》2022

The Galería de las Estatuas is a Mousterian site located within the Cueva Mayor-Cueva del Silo karstic system at the Sierra de Atapuerca (Burgos, Spain). This site is characterised by an important Upper Pleistocene stratigraphic sequence in which a large number of lithic artefacts exhibiting clear Mousterian affinities and a rich assemblage of faunal remains have been found.Additionally, this site has yielded a foot phalanx of a clear Neanderthal affinities and its sediment has yielded Neanderthal mitochondrial and nuclear DNA.Two test pits, GE-I and GE-II, have been excavated since 2008 which have been divided in 5 and 2 lithostratigraphical units, respectively. A minimum age of 45 ka cal BP for this site was obtained by radiocarbon dating in GE-II. This chronology was refined using single-grain Optically Stimulated Luminescence (OSL: 80–112 ka in GE-I and 70–79 ka in GE-II) and single-grain thermally transferred OSL (TT-OSL). Although in all case TT-OSL ages were systematically older than their single-grain counterparts. The detrital sequence is sealed by a flowstone whose base is dated to 53.7 ± 3.5 ka cal BP using U-series dating.In order to better constrain the age of this site, nine herbivorous teeth were collected from the whole sedimentary sequence to be dated by the ESR/U-series dating method though only seven provided modelled ages. Six of them were collected from levels 2 to 5 of the GE-I test pit while the last tooth was taken from level 2 of the GE-II test pit. Our results, ranging between 80 and 110 ka, are in agreement with those obtained by single grain TT-OSL and suggest that the sedimentological levels containing Mousterian lithic artefacts and faunal and human remains began to be deposited during the second part of the MIS5. These results fill a temporal gap in the chronology of the Atapuerca sites for which no contemporary MIS5 date was obtained until recently.  相似文献   

三氯乙烯污染土壤的复电阻率特征和频谱参数研究     

张振宇  许伟伟  邓亚平  任静华  施小清  吴吉春 《地学前缘》2021,28(5):114-124

复电阻率法(complex resistivity, CR)由于其对孔隙水化学性质、固-液界面和流体含量的敏感性已成为具有良好前景的污染物识别工具。本研究选取三氯乙烯(trichloroethylene, TCE)作为典型有机污染物,利用频谱激电仪对TCE污染土壤进行了复电阻率测量,讨论孔隙水盐度、水饱和度和土壤类型对污染土壤的复电阻率特征和频谱参数影响。试验结果表明:污染土样的复电阻率均随水饱和度的降低和孔隙水盐度的减小而增大;土壤黏土含量影响孔隙水连续性,当孔隙水出现不连续状态时,实部和虚部出现大幅度变化。总充电率M随着孔隙水盐度的增加而增加,随水饱和度的降低先减后增。黏土颗粒重排导致的比表面积减小使得总充电率M减小,双电层极化加强使总充电率M升高;平均弛豫时间常数随孔隙水盐度的升高而降低,二者呈对数相关,随水饱和度变化的主要原因为可极化孔隙尺寸的变化。本研究探讨了地球物理参数与水文地质参数间的关系,为SIP方法在实际有机污染场地调查与评估提供了理论依据。  相似文献   

中祁连西段石板墩堆晶岩的地球化学特征及构造意义     

马蓁  刘铮  刘懿馨  王金荣 《现代地质》2018,32(4):667

石板墩堆晶岩位于中祁连地块西段党河断裂带北侧,主要由橄榄岩、蛇纹石化橄辉岩和辉长岩组成,具有多旋回、多韵律层的产出特征。辉长岩LA ICP MS锆石U Pb年龄为(4865 ± 33) Ma。岩石地球化学结果显示,蛇纹石化橄辉岩和辉长岩配分型式十分相似,具有富集大离子亲石元素、亏损高场强元素、LREE相对富集、HREE平坦型分布以及正Eu异常(Eu/Eu*=097~304)的特点。研究结果表明,蛇纹石化橄辉岩、辉长岩为同源岩浆作用的产物,源区为被俯冲流体交代过的软流圈地幔,形成于火山弧环境,是在岩浆作用过程中不断发生堆晶作用,并在堆晶之后再次泵入混合大量新的玄武岩浆反复进行所形成。结合区域大地构造背景,认为中祁连西段是早古生代早期在残留的微陆块基础上形成的一个火山弧增生杂岩地体。  相似文献   

Formation Time of the Kalaqin Metamorphic Core Complex: Constraints from Zircon DatingEI北大核心CSCD     

Lin S.  Xie C.  Xiang B.  Zhao T. 《大地构造与成矿学》2018,(3):570-586

The Kalaqin metamorphic core complex, located on the northern margin of the Yanshan Tectonic Belt, is an important structure to understand the Late Mesozoic destruction processes of the North China Craton. In this study, structural analysis and geochronological investigation were conducted for the Anjiayingzi pluton and associated granodiorite dikes that intruded the core complex. Field observations demonstrated that emplacement of the pluton and dikes took place after the early stage extensional deformation, and intrusions are products of syn-tectonic magmatism during the late stage extension deformation. LA-ICP-MS zircon U-Pb dating yielded ages of 133-131 Ma for the Anjiayingzi pluton and 135 Ma for the dike, which demonstrated that the early extensional deformation took place at 156-135 Ma, rather than the Early Cretaceous as proposed previously. By integrating with other dating results, the early extensional deformation occurred at 156-150 Ma (Late Jurassic) and led to the exhumation of the core complex. The core complex was overprinted by a late extension in the Early Cretaceous. The revision of formation time for the Kalaqin metamorphic core complex further confirms that the extensional deformation took place in the Late Jurassic in the Yanshan tectonic belt, and therefore, it is likely that the northern margin of the North China Craton might have destructed since the Late Jurassic. © 2018, Science Press. All right reserved.  相似文献   

北部湾盆地演化及局部构造成因机制研究   总被引：1，自引：0，他引：1  

李才  杨希冰  范彩伟  胡林  代龙  赵顺兰 《地质学报》2018,92(10):2028-2039

为解决北部湾盆地区域构造演化及成因机制研究不足,局部构造认识存在差异等问题。文中利用二维、三维地震,结合重力、钻井等资料,阐明了北部湾盆地构造演化过程,明确了典型构造发育的成因机制。结果表明：①北部湾盆地具有两坳一隆的构造格局,即北部坳陷带、南部坳陷带和中部隆起带。控凹边界断层为大型低角度拆离正断层,分割变质核杂岩与上盘岩石,其中下盘穹隆状变质核杂岩由地壳中-高级古老变质岩及晚期岩浆岩组成（包括被拆离断层切割的含糜棱状岩石的剪切带,如碎裂岩、角砾岩、糜棱岩和片麻岩等）;②受断裂伸展拆离,同时叠加晚期伸展应力旋转,乌石凹陷东区发育大型断层掀斜反转构造;③新提出“三明治”式地层充填模式下发育的顺层剪切走滑构造的形成机理。“三明治”式刚柔性岩石呈层状分布,在反转掀斜及后期应力场旋转叠加力的作用下,地层非常容易失衡,特别是在其界面处（刚柔界面、柔性界面内部）存在明显的物理力学差异性,二维层状滑动面摩擦阻力非常小,极易造成岩石的顺层剪切走滑。  相似文献   

Field evidence,mineral chemical and geochemical constraints on mafic-felsic magma interactions in a vertically zoned magma chamber from the Chotanagpur Granite Gneiss Complex of Eastern India     

Bibhuti Gogoi  Ashima Saikia  Mansoor Ahmad 《Chemie der Erde / Geochemistry》2018,78(1):78-102

The Nimchak granite pluton (NGP) of Chotanagpur Granite Gneiss Complex (CGGC), Eastern India, provides ample evidence of magma interaction in a plutonic regime for the first time in this part of the Indian shield. A number of outcrop level magmatic structures reported from many mafic-felsic mixing and mingling zones worldwide, such as synplutonic dykes, mafic magmatic enclaves and hybrid rocks extensively occur in our study domain. From field observations it appears that the Nimchak pluton was a vertically zoned magma chamber that was intruded by a number of mafic dykes during the whole crystallization history of the magma chamber leading to magma mixing and mingling scenario. The lower part of the pluton is occupied by coarse-grained granodiorite (64.84–66.61?wt.% SiO₂), while the upper part is occupied by fine-grained granite (69.80–70.57?wt.% SiO₂). Field relationships along with textural and geochemical signatures of the pluton suggest that it is a well-exposed felsic magma chamber that was zoned due to fractional crystallization. The intruding mafic magma interacted differently with the upper and lower granitoids. The lower granodiorite is characterized by mafic feeder dykes and larger mafic magmatic enclaves, whereas the enclaves occurring in the upper granite are comparatively smaller and the feeder dykes could not be traced here, except two late-stage mafic dykes. The mafic enclaves occurring in the upper granite show higher degrees of hybridization with respect to those occurring in the lower granite. Furthermore, enclaves are widely distributed in the upper granite, whereas enclaves in the lower granite occur adjacent to the main feeder dykes.Geochemical signatures confirm that the intermediate rocks occurring in the Nimchak pluton are mixing products formed due to the mixing of mafic and felsic magmas. A number of important physical properties of magmas like temperature, viscosity, glass transition temperature and fragility have been used in magma mixing models to evaluate the process of magma mixing. A geodynamic model of pluton construction and evolution is presented that shows episodic replenishments of mafic magma into the crystallizing felsic magma chamber from below. Data are consistent with a model whereby mafic magma ponded at the crust-mantle boundary and melted the overlying crust to form felsic (granitic) magma. The mafic magma episodically rose, injected and interacted with an overlying felsic magma chamber that was undergoing fractional crystallization forming hybrid intermediate rocks. The intrusion of mafic magma continued after complete solidification of the magma chamber as indicated by the presence of two late-stage mafic dykes.  相似文献   

西昆仑北缘沙拉吾如克铜铅矿地质特征及矿床成因浅析     

黄建国 《地质与勘探》2018,54(1):1-8

西昆仑北缘沙拉吾如克铜铅矿是区域内较为典型的矿床类型之一,矿体主要赋存于加里东期阿勒玛勒克杂岩体中,受沙拉吾如克断裂的控制。矿石矿物主要有黄铜矿、方铅矿、黄铁矿等,矿石铜铅品位相对较贫,一般Cu含量为0.50%~1.33%(平均0.7%),Pb为0.60%~5.99%(平均0.9%)。铜铅矿石的稀土总量(ΣREE)为83.5×10~(-6)~122×10~(-6),相对围岩(ΣREE为257×10~(-6)~342×10~(-6))来说,明显偏低。铜铅矿石的δEu为0.90~1.04,δCe为0.95~0.96,表现为铕和铈的无异常。含矿岩系稀土元素含量及配分模式显示出成矿元素直接来源于阿勒玛勒克杂岩体,特别是来自晚序次的似斑状石英二长岩或二长花岗岩(均为埃达克岩),矿床类型属于斑岩型矿床,为区域上加里东期成矿事件的产物,与大同一带加里东期铜钼矿的形成具有一致的大陆动力地质学过程,即原特提斯洋(西昆仑北洋)向南俯冲消减,进而引起花岗质岩浆活动并成矿。  相似文献