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1.
华南花岗岩两个成岩成矿系列的演化   总被引:17,自引:0,他引:17  
华南花岗岩成岩成矿类型划分的研究,由来已久,如翁文灏(1920)、谢家荣(1936)、闻广(1950—1962)、徐克勤(1975—1981)、胡受奚(1976)、莫柱孙(1977—1981)、郭文魁(1979)、程裕淇(1979)、张炳禧(1980)、涂光炽(1980—1981)、杨超群(1981)、郭令智(1981)、李春煜(1981)等教授及江西地科所(1977—1981)、江西冶地所(1979—1981)、浙江地科所(1981)、章崇真(1980)、李逸群(1981)、周维勋(1980)、李宗裕(1981)、吴永兴(1981)等都从事过这方面的研究;初期的工作,多属一般性的论述,解放  相似文献   

2.
回顾了锶铁钛矿(crichtonite)族矿物在我国的研究历史,从产状、物理性质、化学成分以及晶体结构等方面重点介绍了锶铁钛矿族新成员——冕宁铀矿。锶铁钛矿族矿物属三方晶系,结构通式为A~ⅫB~ⅥC_(18)~ⅥT_2~Ⅳ(Φ)_(38)。冕宁铀矿是锶铁钛矿族第15个成员,产自牦牛坪稀土矿包子山煌斑岩破碎带中(N28°24'20″,E101°59'3″),经验化学式为[□_(0.322)(Pb_(0.215)Ba_(0.037)Sr_(0.036)Ca_(0.010))_(0.298)(Ce_(0.128)La_(0.077)Nd_(0.012))_(0.217)(Na_(0.127)K_(0.036))_(0.163)]_(1.000)(U_(0.447)~(4+)Mn_(0.293)U_(0.112)~(6+)Y_(0.091)Zr_(0.023)Th_(0.011))_(0.977)(Fe_(1.224)~(3+)Fe_(0.243)~(2+)Mg_(0.023)P_(0.008)Si_(0.006_□_(0.496))_(2.000)(Ti_(12.464)Fe_(5.292)~(3+)V_(0.118)~(5+)Nb_(0.083)Al_(0.026)Cr_(0.017)~(3+))_(18.000)O_(38.000);晶胞参数为a=1.03462(5)nm,c=2.08372(2)nm,V=1.93165(20)nm~3,Z=3,空间群R3;晶体多呈半自形板状,粒径1~2 mm,黑色,条痕黑色,半金属光泽,不透明,性脆,贝壳状断口,解理、裂开和荧光性均不发育;莫氏硬度约为6,密度为4.62(8)g/cm~3。由于铀等放射性元素的辐射,冕宁铀矿发育有不同程度的非晶质化。冕宁铀矿是锶铁钛矿族第一个A位以空位为主的矿物种。该矿物以其产地命名,已获得了国际矿物学会新矿物及矿物分类命名委员会(CNMNC-IMA)的正式批准(IMA 2014-072)。  相似文献   

3.
通过振动台试验,对钢锚杆(索)与玄武岩纤维塑料增强筋(BFRP)锚杆(索)的应变峰值分布规律进行了分析,并利用小波包工具对不同频带下锚杆(索)的应变响应情况进行研究。试验结果表明:(1) BFRP锚杆(索)与坡体协同变形的效果较钢锚杆(索)更加明显;(2) BFRP锚杆(索)上的应变值均要大于钢锚杆(索)上对应测点的应变值,且单独对钢锚杆(索)及BFRP锚杆(索)而言,锚杆(索)端部处的应变值均要大于锚杆(索)尾部处的应变值;(3)对应变起影响作用的主要频段为第一频带(0. 1~6. 26 Hz)和第二频带(6. 26~12. 51 Hz),土体对于高频(12. 51 Hz以上)地震波的吸收比较明显。其研究结果可为BFRP锚杆(索)加固高边坡的动力合理性设计提供科学依据。  相似文献   

4.
华夏古板块与扬子古板块结合带内的广丰、玉山红色碎屑沉积盆地均有橄榄玄粗岩产出,SHRIMP锆石UPb年代学研究表明,橄榄玄粗岩锆石U-Pb年龄为93±1 Ma,属晚白垩世早期的产物。广丰盆地橄榄玄粗岩(~(87)Sr/~(86)Sr)_i值为0.706 191~0.706 352,εNd(t)值为0.27~0.55,(~(206)Pb/~(204)Pb)_i值为18.045~18.080,(~(207)Pb/~(204)Pb)_i值为15.503~15.543,(~(208)Pb/~(204)Pb)_i值为38.240~38.256;玉山盆地橄榄玄粗岩(~(87)Sr/~(86)Sr)_i值为0.705 856~0.706 024,εNd(t)值为1.74~1.93,(~(206)Pb/~(204)Pb)_i值为17.956~18.063,(~(207)Pb/~(204)Pb)_i值为15.456~15.498,(~(208)Pb/~(204)Pb)_i值为38.195~38.232。在(~(87)Sr/~(86)Sr)_i-(~(206)Pb/~(204)Pb)_i、(~(143)Nd/~(144)Nd)_i-(~(206)Pb/~(204)Pb)_i和(~(143)Nd/~(144)Nd)_i-(~(87)Sr/~(86)Sr)i图解中,广丰、玉山盆地橄榄玄粗岩均位于亏损地幔(DMM)和EMⅡ型富集地幔之间,而且(~(87)Sr/~(86)Sr)_i和(~(206)Pb/~(204)Pb)_i呈正相关,(~(143)Nd/~(144)Nd)_i和(~(206)Pb/~(204)Pb)_i呈负相关,指示其源区中可能均有DMM和EMⅡ型地幔的贡献;玉山盆地橄榄玄粗岩更偏向DMM端员,指示其DMM端员所占的比例更高。广丰、玉山盆地橄榄玄粗岩具有EMⅡ型地幔的贡献,说明华夏古板块与扬子古板块结合带的岩石圈地幔与华夏古板块的岩石圈地幔属相同类型,为华夏古板块俯冲于扬子古板块之下提供了新的证据。  相似文献   

5.
《地质论评》2001,47(6):664-664
卜昌森(405)卜文瑞(108)陈斌(361)陈荣(602)陈柏林(111)陈炳辉(88)陈小明(317)陈衍景(261)程裕淇(1)崔军文(157)代世峰(383)单新建(648)董申保(356)董永观(397)费安玮(596)冯有良(278)葛宁洁(184)顾家裕(201)顾连兴(188)桂和荣(321)韩非(102)韩同林(382)贺义兴(82)赫英(500)洪友崇(345)侯增谦(344)黄思静(301)黄小龙(542)黄智龙(27)贾建业(250)江思宏(438)金章东(42)匡耀求(119)雷振宇(415)BU Changsen(410)BU Wenrui(108)CHEN Bin(367)CHEN Binghui(94)CHEN Bolin(111)CHEN Rong(607)CHEN Xiaoming(321)CHEN Yanjing(271)C…  相似文献   

6.
江苏白垩纪孢粉组合序列   总被引:9,自引:5,他引:4  
根据近年来获得的孢粉化石材料和前人资料 ,建立了江苏白垩纪的孢粉组合序列 ,它们是 :  1)贝里阿斯期至凡兰吟期 (Berriasian— Valanginian)的 Schizaeoisporites- Classopollis annulatus- Ginkgocycadophytus nitidus组合 (云合山组 ) ;  2 )阿普特期至阿尔必期 (Aptian— Albian )的 Cicatricosisporites- Classopollis annulatus-Psilatricolpites组合 (葛村组 ) ;  3)土伦期 (Turonian )的 Schizaeoisporites- Polycingulatisporites- Cycadopites-Cranwellia组合 (浦口组 ) ;  4)科尼亚克期至桑顿期 (Coniacian— Santonian)的 Schizaeoisporites- Classopolisannulatus- Lytharites组合 (赤山组 ) ;  5 )坎潘期 (Campanian )的 Schizaeoisporites- Tricolporopollenitesmicrocirculatus- Betpakdalina组合 (泰州组下部 ) ;  6 )马斯特里赫特期 (Maastrichtian)的 Pterisisporites-Exesipollenites- K urtzipites组合 (泰州组上部 ) ; 欧特里沃期至巴列姆期 (Hauterivian— Barremian)和塞诺曼期(Cenom ainan)的暂缺。  相似文献   

7.
基于前期调查,采集水稻籽实样品共50件,在选定的3处地块采集9组土壤和水稻组合样品,每组样品包括根系土、水稻根系、水稻茎和籽实,分析其各部位的重金属元素含量,探究重金属元素在植物不同部位的迁移与富集机理。研究区水稻不同部位的元素富集规律为根系富集系数F(As)>F(Cu)>F(Cd)>F(Zn)≈F(Hg)>F(Cr)≈F(Ni)≈F(Pb),茎部富集系数F(Hg)>F(Zn)≈F(Cu)>F(Cd)>F(As)>F(Cr)>F(Ni)>F(Pb),籽实富集系数F(Zn)>F(Cu)>F(Cd)>F(Ni)>F(As)≈F(Cr)>F(Pb),水稻植株内重金属元素含量分布规律为根系>>茎>籽实。重金属元素在该系统中的迁移系数和迁移模式可分为4类。研究结果对土壤环境修复与合理利用等有一定的借鉴意义。  相似文献   

8.
北京市区春季交通源大气颗粒物污染水平及其影响因素   总被引:18,自引:0,他引:18  
文中以PM_(2·5)和PM_(10)为研究对象,于2005年3月13日至19日前后6d的时间内,在成府路东口、前门2个地区设立采样点,研究分析了北京市春季交通源大气颗粒物的污染水平及其影响因素。研究表明:(1)PM_(2·5)和PM_(10)的质量浓度存在明显的日变化规律,在工作日所测得的PM_(2·5)和PM_(10)的质量浓度值要高于在周末所测得的质量浓度值;(2)PM_(2·5)和PM_(10)的质量浓度存在明显的时变化规律,在7:00~9:00,19:00~21:00和23:00之后,PM_(2·5)和PM_(10)的质量浓度分别达到三个峰值;(3)PM_(2·5)和PM_(10)的质量浓度随着温度的变化而存在明显的变化规律,PM_(2·5)和PM_(10)质量浓度的最大值与低温(0~5℃)有关,而PM_(2·5)和PM_(10)质量浓度的最小值在高温(11~15℃)时被观察到;(4)PM_(2·5)和PM_(10)的质量浓度的最大值与高湿度值(36%~46%)有关,而PM_(2·5)和PM_(10)质量浓度的最小值在低湿度值(11%~25%)时被观察到;(5)通过对成府路东口、前门采样点颗粒物浓度与风级比较,发现二者呈明显的反相关关系,由此可见,风力大小对特定区域的颗粒物浓度起决定性作用;(6)与国外一些城市的PM_(10)的污染水平相比,在北京成府路东口、前门所测得的PM_(10)的质量浓度都要比国外一些城市高,由此可见,汽车尾气仍是北京市区大气颗粒物的主要来源之一。  相似文献   

9.
中国南方现代块根块茎类植物淀粉粒形态分析   总被引:2,自引:0,他引:2  
为了研究块根块茎类植物的利用历史,对中国南方常见块根块茎植物天南星科(Araceae)、薯蓣科(Dioscoreaceae)、百合科(Liliaceae)、睡莲科(Nymphaeaceae)、莎草科(Cyperaceae)、菱科(Trapaceae)、姜科(Zingiberaceae)和豆科(Leguminosae)中...  相似文献   

10.
本文以野外土化学分析资料和室内原状土Ph(Ⅱ)、Cu(Ⅱ)和Hg(Ⅱ)的混合溶液淋滤实验资料为基础,以热力学基本原理为理论根据,建立Pb(Ⅱ)、Cu(Ⅱ)和Hg(Ⅱ)在土层系统中的迁移形式的数学模型。以此,评价Pb(Ⅱ)、Cu(Ⅱ)和Hg(Ⅱ)在包气带土层系统中的积累位置、积累方式及其迁移条件。确定配位体(∑HCO~-_3、∑Cl~-,∑SO~(2-)_4)浓度变化对于Pb(Ⅱ)、Cu(Ⅱ)和Hg(Ⅱ)稳定迁移形式和稳定迁移浓度大小的影响程度。  相似文献   

11.
A Barremian microflora is recorded in the terrigenous facies (Weald) of the Lower Cretaceous in the northern region of the Province of Valencia (Spain), these beds have been poorly dated up to now due to the absence of fossils. The Villar del Arzobispo microflora correspond unquestionably to the Barremian-Aptien period, but the numerical importance of derived forms from the Jurassic, the remarkable variety of forms of Cicatricosisporites, and the rareness of pollen of Angiosperms, indicate a Barremian age to be more likely.This discovery permits us to establish the stratigraphical relationship of this terrigenousfacies of Villar del Arzobispo with the dated “Weald” of other areas of the Iberian Chain and to give a complete chrono-stratigraphical interpretation to the different litho-stratigraphical units that constitute the Lower Cretaceous of this region.  相似文献   

12.
苏皖坡缕石粘土中蛋白石特征及其成因意义   总被引:1,自引:0,他引:1  
TEM和XRD研究表明,在苏皖坡缕石粘土矿床的蛋白石坡缕石层中存在0pal-A和0pal-CT两种结构的蛋白石。蛋白石坡缕石层主要含坡缕石、opal-A、opal-CT,以及少量白云石和其它矿物,由富opal-A层和富opal-CT层互层组成,交互层的厚度在几个厘米左右。蛋白石坡缕石层中的矿物基本是自生矿物,从蒸发湖水中化学沉淀形成。矿物组成特征研究表明,蛋白石坡缕石层的矿物组分(Si、Mg、Al)来源于盆地周围玄武岩淋滤的浅层地下水。根据Opal-A和Opal-CT溶解度图解和城缕石、白云石形成物理化学条件图解,当湖水具有高浓度溶解SiO2和Mg^2 时,有利于opal-A和坡缕石形成,当湖水具有低浓度溶解SiO2时,有利于opal-CT结晶。因此,沉淀SiO2的结构状态取决于地下水补给的湖水溶解SiO2浓度。富opal-A和富opal-CT交互层的形成是古气候、古水文周期性变化的指示。富opal-CT层指示高地下水补给流入量,低蒸发量,湖水低盐度和溶解组分,代表湿润气候时期;而富opal-A层代表低地下水补给流入量,高蒸发量,高溶解组分浓度,代表干旱气候时期。  相似文献   

13.
The investigation of the occurrence of lead in dated snow and ice from Greenland and Antarctica has played a major role in our understanding of the history of the pollution of the atmosphere of our planet by this metal. Such studies have however proved to be very demanding, mainly because of the extreme purity of polar snow and ice. Reliable measurements can be obtained only if ultra-clean and highly sensitive procedures are used, as pioneered by Clair Patterson. The Greenland data show evidence of large-scale pollution of the atmosphere of the Northern Hemisphere for lead as early as two millennia ago during Greco–Roman times, especially because of mining and smelting activities in southern Spain. It peaked at the end of the 1960s, with lead concentrations in snow about 200 times higher than natural values, before declining during recent times because of the fall in the use of leaded gasoline. Lead pollution in Antarctica was already significant at the end of the 19th century as a consequence of whaling activities, the traffic of coal-powered ships crossing the Cape Horn, and mining activities in South America, South Africa and Australia. After declining because of the opening of the Panama Canal, the great economic depression and World War II, it reached a maximum during the 1980s, with lead concentrations 20 times higher than natural values. Other studies focus on past natural variations of lead in ancient ice dated from the last climatic cycles. To cite this article: C. Boutron et al., C. R. Geoscience 336 (2004).  相似文献   

14.
Summary Finite element analyses were conducted to investigate the magnitude of tensile strains imposed on landfill liners due to the formation of subsurface cavities. The study incorporated the significance of using geogrids to reduce the magnitude of strains and possibly the potential for collapse of landfill liners. Variations of key parameters included depth of overburden (D) and diameter of the cavity (B). Estimated stress distributions were compared to theoretical values obtained from a model reported in the literature. Results indicated that, contrary to conventional wisdom, the critical area based on the mechanics of arching was above the edge of the cavity where stress concentration occurred. Incorporation of geogrid reinforcement reduced the magnitude of tensile strains. The tensile force in the geogrid was dependent upon the size of the cavity, the depth of the overburden, and the applied pressure.  相似文献   

15.
This paper concerns the evaporite units, depositional systems, cyclicity, diagenetic products and anhydritization patterns of the Calatayud Basin (nonmarine, Miocene, central Spain). In outcrop, the sulphate minerals of these shallow lacustrine evaporites consist of primary and secondary gypsum, the latter originating from the replacement of anhydrite and glauberite. In the evaporative systems of this basin, gypsiferous marshes of low salinity can be distinguished from central, saline lakes of higher salinity. In the gypsiferous marsh facies, the dominant, massive, bioturbated gypsum was partly replaced by synsedimentary chert nodules and siliceous crusts. In the saline lake facies, either cycles of gypsiferous lutite‐laminated gypsarenite or irregular alternations of laminated gypsum, nodular and banded glauberite, thenardite and nodular anhydrite precipitated. Early replacement of part of the glauberite by anhydrite also occurred. Episodes of subaerial exposure are represented by: (1) pedogenic carbonates (with nodular magnesite) and gypsiferous crusts composed of poikilitic crystals; and (2) nodular anhydrite, which formed in a sabkha. Additionally, meganodular anhydrite occurs, which presumably precipitated from ascending, highly saline solutions. The timing of anhydritization was mainly controlled by the salinity of the pore solutions, and occurred from the onset of deposition to moderate burial. Locally, a thick (>200 m) sequence of gypsum cycles developed, which was probably controlled by climatic variation. A trend of upward‐decreasing salinity is deduced from the base to the top of the evaporite succession.  相似文献   

16.
Relative percentages of sand, silt, and clay from samples of the same till unit are not identical because of different lithologies in the source areas, sorting in transport, random variation, and experimental error. Random variation and experimental error can be isolated from the other two as follows. For each particle-size class of each till unit, a standard population is determined by using a normally distributed, representative group of data. New measurements are compared with the standard population and, if they compare satisfactorily, the experimental error is not significant and random variation is within the expected range for the population. The outcome of the comparison depends on numerical criteria derived from a graphical method rather than on a more commonly used one-way analysis of variance with two treatments. If the number of samples and the standard deviation of the standard population are substituted in at-test equation, a family of hyperbolas is generated, each of which corresponds to a specific number of subsamples taken from each new sample. The axes of the graphs of the hyperbolas are the standard deviation of new measurements (horizontal axis) and the difference between the means of the new measurements and the standard population (vertical axis). The area between the two branches of each hyperbola corresponds to a satisfactory comparison between the new measurements and the standard population. Measurements from a new sample can be tested by plotting their standard deviation vs. difference in means on axes containing a hyperbola corresponding to the specific number of subsamples used. If the point lies between the branches of the hyperbola, the measurements are considered reliable. But if the point lies outside this region, the measurements are repeated. Because the critical segment of the hyperbola is approximately a straight line parallel to the horizontal axis, the test is simplified to a comparison between the means of the standard population and the means of the subsample. The minimum number of subsamples required to prove significant variation between samples caused by different lithologies in the source areas and sorting in transport can be determined directly from the graphical method. The minimum number of subsamples required is the maximum number to be run for economy of effort.  相似文献   

17.
18.
1 IntroductionThe term“Environmental Geochemical Baseline(EGB)”first appeared in the International Geochemi-cal Mapping Program (IGCP259) and the InternationalGeochemical Baseline Program (IGCP360) of Interna-tional Geography Contrast Program. The defin…  相似文献   

19.
Discontinuities such as fractures or cracks are common in geo-materials. Connectivity is a comprehensive parameter that includes the influence of length, orientation and density of the discontinuities. The main objectives of this paper are to define connectivity based on the statistical geometrical parameters of a network of random discontinuities and to quantify the hydraulic properties of the network using connectivity. An analytical method is first proposed to evaluate connectivity through the density of degree of freedom (DDOF). The analytically estimated DDOF is verified using numerical analysis. DDOF increases with the increases in the mean length, relative orientation and density of the random discontinuity network. Connectivity becomes better and the permeability becomes larger with increasing DDOF. The representative element volume (REV) of a random discontinuity network can be estimated based on connectivity. When a discontinuity network is poorly connected, a REV does not exist when the size of the discontinuity network is smaller than 10 times of the mean length of the discontinuities. When a discontinuity network is normally connected, a REV exists when the REV size is smaller than 10 times of the mean length of the discontinuities. When the discontinuity network is highly connected, the REV size is only 2–4 times of the mean length of the discontinuities. The results indicate that DDOF is a good indicator to quantify the connectivity of a random discontinuity network and the relationship between connectivity and permeability.  相似文献   

20.
Potato starch and dextrins resulting from thermolysis of potato starch in the absence of reagents and presence of -amino acids are promising depressants for separation of lead and copper minerals present in the Polish industrial copper concentrates. The polysaccharides were used for differential xanthate flotation of the final industrial concentrates produced by flotation with sulfhydryl collectors in the absence of depressants. The polysaccharides depressed galena and provided froth concentrate rich in chalcocite and other copper minerals as well as cell product containing lead minerals. The best results of separation were obtained in the presence of plain dextrin prepared by a thermal degradation of potato starch. The industrial concentrate containing 18.5% Cu and 5.5% Pb was divided into a froth product containing 38.1% Cu with 77% recovery of copper and a cell product assaying 7.3% Pb with 83% recovery of lead. It was accomplished using 2500 g/t of dextrin, 50g/t of potassium ethyl xanthate, and 50 g/t of frother (α-terpineol). The pH of flotation was 8.0–8.2.  相似文献   

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