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1.
覆盖层下三维异常体对垂直磁偶极源的电磁响应   总被引:1,自引:0,他引:1  
针对地下半空间存在三维异常体及覆盖层情况,计算了垂直磁偶极子的场,计算结果表明,σ1与σ2接近时,覆盖层影响减小σ1增加覆盖层影响增大,对于不同的σ2/σ1值,场幅值对高频(f≥2kHz)和低频(f≤10Hz)都明显减小,只在2kHz≥f≥10Hz之间,场幅值可达最大,还表明垂直磁偶极子的场具有较强的岩性识别和分层能力。  相似文献   

2.
辽吉内生硼矿分布于宽甸群的高小岭组(Pt1kn4)、老营沟组(Pt1kn6)和砖庙组(Pt1kn7)地层中。在硼矿床中,硼镁铁矿-硼铁矿系列的矿物有富镁硼铁矿、富铁硼镁铁矿和富镁硼镁铁矿。它们的矿物学特征取决于j值[FeO/(FeO+MgO)],f值增大,硼镁铁矿的反射色、反射多色性和偏光色明显;红外光谱则表现为ν2和ν4的振动频率低移;晶胞参数a0和c0增大。f值减小,颜色、多色性变化明显。从Pt1kn4→Pt1kn6→Pt1kn7,硼镁铁矿的f值逐渐减小,氧化系数增大,其形成向着富镁、氧化程度高的方向演化。硼镁铁矿的矿物学特征具有含硼层的指示意义。  相似文献   

3.
本文论述双频透射电磁波电导率层析成象方法。设|E1|,|E2|为在远场区观测的同一电偶极天线的两个辐射电场强度。如地质介质的电导率连续变化,观测场强的辐射频率ω1,ω2之差较小,则有如下的电导率层析成象方程|E1|-|E2|=20log(ω1/ω2)+20log(e)μ/2(ω2-ω1)∫σ~(r)dr式中σ^=σ,σ为介质的电导率。双频透射电磁波电导率层析成象方法克服了长期困扰电磁波吸收层析成象的初始辐射场强计算问题,应用实例表明它可获得更精确的层析图。  相似文献   

4.
冀西北麻粒岩是我国北方麻粒岩带的重要组成部分,其年龄对探讨我国地壳早期演化历史具有重要价值。本文报道了采自赤城伙房村和崇礼上新营变质岩样品的地球化学特征和Sm-Nd同位素年龄。赤城伙房村变质岩年龄为2513±55(2σ)Ma,INd=0.50944±5(2σ),εNd(t)=+1.2±0.5;崇礼上新营变质岩年龄为2667±90(2σ)Ma,INd=0.50930±8(2σ),εNd(t)=+2.4±0.7。冀西北变质岩可能存在两个系列,其原岩分别形成于2900~2800Ma和2700~2600Ma。该区最早地壳可能形成于2932±84(σ)Ma  相似文献   

5.
本文用强功率四圆单晶衍射仪精确地修正了独居石和磷钇矿的晶体结构。独居石[Monazite-(Ce),CePO4]属单斜晶系,a=6.7843(17),b=6.9891(12),c=6.4592(10),β=103.626(16)°,Z=4,空间群为P21/n。使用1106个[F≥3σ(F)]的独立衍射点,经多轮最小二乘法修正后,最终获得偏离因子R=0.060。独居石的结构由孤立的[PO4]四面体构成,Ce位于[PO4]四面体包围之中,Ce的配位数为9,独居石的Ce—O平均键长为2.552,P—O平均键长为1.528。磷钇矿(Xenotime,YPO4)属四方晶系,其晶格常数为:a=6.8791(24),c=6.0147(19),Z=4,空间群为I4I/amd(No.141)。使用142个[F≥3σ(F)]的独立衍射点,经多轮最小二乘法修正后,最终获得偏离因子R为0.0483。磷和氧形成四面体配位,其P—O平均键长为1.543;稀土钇与氧原子相连构成八次配位,其Y—O平均键长为2.333。  相似文献   

6.
碲在官田黄铁矿矿床中的聚集及地球化学   总被引:1,自引:0,他引:1  
黄富荣 《地球学报》1998,19(1):50-58
碲是官田黄铁矿矿床中的重要伴生组分,高度聚集在寄主矿物黄铁矿中,含碲矿物是楚碲铋矿、赫碲铋矿和碲铋矿。成碲和聚碲的物理化学条件是:压力低于10MPa,温度140~220℃,含碲流体的盐度低于12ω(NaCl),离子类型为SO2-4-K+-Ca2+型,pH值为4.4~5.8,Eh值为-0.5V,fO2<10-25×105Pa,fCO2<101.8×105Pa,fS2为(10-21.34~10-15.72)×105Pa,fTe2为(10-11.93~10-8.72)×105Pa。含碲热液具多来源,成碲和聚碲时期以天水为主导。碲的可能迁移形式是[TeS3]2-和[AuTeS3]-。文章最后与大水沟独立碲矿床进行了综合对比。  相似文献   

7.
针对岩层中介电常数和磁导率随深度变化的情况,给出了水平磁偶极子源电磁场的频率域特征及相应的变化规律。采用Kong给出的汉克尔J0变换线性滤波器(241点)和汉克尔J1变换线性滤波器(241点)算法,选用若干个地电模型,讨论了介质的磁导率和介电常数变化时的水平磁偶极子电磁场响应特征。计算结果表明,磁场的Hx、Hy分量幅值基本没有受到磁导率变化的影响,而磁场Hz和电场Ex、Ey分量幅值却随着磁导率的增大而增大;当频率低于106Hz时,介电常数变化对电磁场幅值基本没有影响,但在频率高于107 Hz时,介电常数变化对电磁场幅值受到不同程度的影响。  相似文献   

8.
横岭关铜矿床地球化学研究   总被引:1,自引:0,他引:1  
对横岭关铜矿床中稀土元素、同位素和矿物包裹体地球化学研究表明,矿床形成温度为350℃±30℃;压力为38×10~5Pa~240×10~5Pa;盐度为30wt%~42wt%;logfo_2为-30.41~-31.47;logfs_2为-5.4~-8;pH值为7.3;logfco_2为-2.49;铜的溶解度(logm_(Cu))为-5.87~-2.21。围岩的铅-铅同位素年龄为1775×10~6a,矿石的铅-铅同位素年龄为1845×10~6a;矿石硫同位素组成,δ~(34)S为-8.1‰~36.9‰,显示出硫同位素为非平衡特征;碳酸盐岩的碳同位素组成,δ~(13)C为-7.1‰~-2.6‰,δ~(13)C_(∑C)为-5.3‰;成矿流体的氢氧同位素组成具有变质热卤水的特点,认为该矿床属于变质热卤水成矿。  相似文献   

9.
泥河湾地区晚新生代生物地层带   总被引:7,自引:0,他引:7       下载免费PDF全文
本文根据岩石地层,哺乳动物化石及古地磁资料的综合分析研究,将泥河湾地区晚新生代生物地层划分为5个生物地层时限带,并推算出每个带的年限,它们是:(1)Hipparion houfenense时限带,?-3.30Ma;(2)Mimomys orientalis时限带,3.30-2.48Ma;(3)Mimomys youhenicus时限带,2.48-1.87Ma;(4)Allophainoys cf.  相似文献   

10.
重点研究了414矿床石英流体包裹体特征及成矿物理化学条件,其成矿温度490~530℃;成矿压力为1080×10 ̄5Pa;成矿溶液的pH值为4.82~4.83;Eh值为-0.425~-0.436伏特,fo_2:为10 ̄(-30.44)~1O ̄(-30.09)。  相似文献   

11.
Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.  相似文献   

12.
Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.  相似文献   

13.
Robert L. Linnen   《Lithos》2005,80(1-4):267-280
The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H2O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H2O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.  相似文献   

14.
15.
Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ1 roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).  相似文献   

16.
正20141520 Bo Ying(Key Laboratory of Metallogeny and Mineral Assessment,MLR,Beijing 100037,China);Liu Chenglin Saline Spring Hydrochemical Characteristics and Indicators for Potassium Exploration in Southwestern and Northern Tarim Basin,Xinjiang(Acta Geoscientica Sinica,ISSN1006-3021,CN11-3474/P,34(5),2013,p.594-602,5 illus.,3 tables,28 refs.)  相似文献   

17.
正20141243Chen Ge(Hangzhou Research Institute of Petroleum Geology,PetroChina,Hangzhou 310023,China);Si Chunsong Study on Sedimentary Numerical Simulation Method of Fan Delta Sand Body(Journal of Geology,  相似文献   

18.
正20142599Chen Sanming(Guangxi Key Laboratory of Concealed Deposits Exploration,Guilin University of Technology,Guilin541004,China);He Yuzhou Block Model and Reserves Estimation of Panzhihua Iron Deposit Based on 3D Geological Modeling(Journal of Guilin University of Technology,ISSN1674-9057,CN45-1375/N,33(4),2013,p.610-615,9illus.,1table,15refs.)  相似文献   

19.
正20140594 Bai Daoyuan(Hunan Institute of Geology Survey,Changsha 410016,China);Zhong Xiang Faults in the Jingzhou Basin and Their Tectonic Settings(Geotectonica et Metallogenia,ISSN1001-1552,CN44-1595/P,37(2),2013,p.173-183,6illus.,59refs.)Key words:basin evolution,tectonic setting,South China In the Upper Paleozoic and Jurassic se-  相似文献   

20.
正20141912Cao Hui(State Key Laboratory for Continental Tectonics and Dynamics,Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China)Gravitational Collapse and Folding during Orogenesis:A Comparative Study of FIA Trends and Fold Axial Plane Traces(Geology in China,ISSN1000-3657,CN11-1167/P,40(6),2013,p.1818-1828,9illus.,35refs.,with  相似文献   

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