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1.
E.E.Milanovsky 《《幕》》2004,27(2):101-106
Editorial note--The International Commission on the History of Geological Sciences has undertaken to organize a series of short articles for Episodes on the history of the different Sessions of the International Geological Congress. These were held as follows:France (1878), Italy (1881), Germany (1885), UK (1888), USA(1891), Switzerland (1894), Russia (1897), France (1900), Austria(1903), Mexico (1906), Sweden (1910), Canada (1913), Belgium(1922), Spain (1926), South Africa (1929), USA (1933), USSR(1937), UK (1948), Algeria (1952), Mexico (1956), Denmark/Finland/Norway/Sweden/Iceland (1960), India (1964), Czechoslovakia(1968), Canada (1972), Australia (1976), France (1980), USSR(1984), USA (1989), Japan (1992), China (1996), Brazil (2000). Any authors wishing to offer contributions on the meetings in Mexico(1906), Canada (1913), Belgium, Denmark, India, Canada (1972),and Brazil are invited to contact the INHIGEO Secretary-General at: doldroyd@optushome.com.au. The papers will not appear inchronological order.  相似文献   

2.
显生宙全球气候变化与生物绝灭事件的联系   总被引:3,自引:1,他引:3  
根据显生宙各地质时期全球气候敏感沉积物和生物地理单元数据库,显生宙(寒武纪至中新世)可识别出24次全球范围内不同级别的气候变化事件。有些事件与全球生物事件有着密切的联系,而不少则并无重要联系,即使这两种事件发生的时间和规模上存在着明显的一致性,也并不一定就存在着因果关系。这24次事件根据二者的一致性和不一致性,可归纳为两类:(1)早寒武世末(一致);(2)晚寒武世末(不一致);(3)早奥陶世末(Ibexian末,不一致);(4)奥陶纪末(一致);(5)志留纪兰多维列世(不一致);(6)志留纪文洛克世早期(不一致);(7)志留纪文洛克世末(不一致);(8)志留纪罗德洛世末(不一致);(9)志留纪普利道里世末(不一致);(10)早泥盆世埃姆斯期初(不一致);(11)中泥盆世艾菲尔期末(一致);(12)中泥盆世吉维特期末(一致);(13)晚泥盆世弗拉斯期末(一致);(14)泥盆纪末(不一致);(15)早石炭世末(一致);(16)晚石炭世维斯发期末(一致);(17)早二叠世萨克马尔晚期(一致);(18)二叠纪末(一致);(19)早三叠世(一致);(20)中—晚三叠世(不一致);(21)早侏罗世赫塘期(不一致);(2?  相似文献   

3.
海拉尔盆地海参1井伊敏组孢粉组合的地层意义   总被引:3,自引:0,他引:3  
海参1井伊敏组孢粉化石异常丰富,自下而上可以划分出3个孢粉组合:Impardecispora-Cyathidites-Clavatipollenites组合,Stereisporites-Deltoidospora-Asteropollis组合,Appendicisporites-Asteropollis-Tricolpites组合,分别分布于伊敏组一段、二段和三段,组合特征明显,是海拉尔盆地乌尔逊凹陷划分伊敏组与大磨拐河组的重要生物依据之一,更是伊敏组内三段划分和井间对比的生物依据之一。3个孢粉组合中见有属种繁多的海金沙科孢子及其他繁盛于早白垩世中晚期的孢子花粉,结合在绝大多数样品中发现的早期被子植物花粉的情况分析,推测含这3个孢粉组合的伊敏组地质时代为早白垩世巴列姆期—早阿尔必期(Barremian—Early Albian)。  相似文献   

4.
Pan-sharpening is the process of transferring the spatial resolution of panchromatic (PAN) image to a multispectral (MS) image for producing a single image with high spatial detail and rich spectral information. In this study, PAN and MS imagery of Quickbird-2 and Landsat-8 are fused separately, using ten different pan-sharpening methods such as principal component analysis (PCA), modified-intensity hue saturation (M-IHS), multiplicative, brovey transform (BT), wavelet-principal component analysis (W-PCA), hyperspectral color space (HCS), high-pass filter (HPF), Gram-Schmidt (GS), Fuze Go, and non-subsampled contourlet transform (NSCT). The effectiveness of these techniques is assessed and compared by qualitative analysis and 14 quantitative analysis methods including bias, correlation coefficient (CC), difference in variance (DIV), relative dimensionless global error in synthesis (ERGAS), universal image quality index (Q), relative average spectral error (RASE), root mean square error (RMSE), structural similarity index method (SSIM), signal-to-noise ratio (SNR), peak SNR (PSNR), spatial correlation coefficient (SCC), image entropy (E), and gradient and quality with no reference image (QNR). The results of both analysis types show that the Fuze Go and NSCT produced the best fused image with high spatial detail and rich spectral information followed by the HPF and GS.  相似文献   

5.
In accordance with the set of species-defining chemical elements in minerals, n-component systems (where n = 1, 2, 3, 4, 5, 6, 7, 8, 9, 10) for all mineral species (4952) known to 2014 inclusive were distinguished. Seventy chemical elements have been established to be species-defining, which are distributed by mineral systems as follows: 1 (29), 2 (62), 3 (68), 4 (61), 5 (61), 6 (55), 7 (49), 8 (38), 9 (28), and 10 (19). The number of mineral species in which certain chemical elements are species-defining has been specified. Oxygen (4041), hydrogen (2755), silicon (1448), calcium (1139), sulfur (1025), aluminum (960), iron (917), sodium (914), copper (616), phosphorous (580), arsenic (575), and magnesium (550) are the leading elements in minerals in the Earth’s crust. It has been found that the most species-defining elements are normally distributed by mineral systems. The distributions of mineral species in various systems from the Khibiny and Lovozero, Kola Peninsula, Russia; and Mont Saint-Hilaire, Quebec, Canada peralkaline plutons were compared and the characters of species-defining element distribution in these localities were compared. Si, Na, K, C, F, Ti, Ce, Zr, Nb, Sr, and Th are “excess” species-defining elements in minerals from the plutons compared to the total number of mineral species, whereas S, Cu, Pb, Cl, B, Te, Ag, Ni, and Be are “scarce” elements.  相似文献   

6.
李伍平  李献华 《地球科学》2005,30(6):761-770
根据全岩K-Ar年龄(287.5~243.6Ma), 辽西朝阳长茂河子辉绿岩墙群形成于晚古生代.这些辉绿岩分为低铁钛辉绿岩和高铁钛辉绿岩2种, 以低铁钛辉绿岩为主.低铁钛辉绿岩以低TiO2(< 2%)、FeOt(12.39%~15.33%)、V(227~335μg/g)、Sc(24~36μg/g) 含量和高的SiO2 (45.61%~47.72%)、Al2O3(12.51%~16.71%)、MgO(6.66%~9.31%)、K2O(0.57%~2.39%)、Cr(107~177μg/g)和Ni(96~235μg/g) 含量, 以及低Ti/Y(327~496)和Ti/Zr (69~114) 比值为特征, 类似于大陆拉斑玄武质岩石; 高铁钛辉绿岩以高的TiO2 (5%~6%)、FeOt(22.13%~22.16%)、V(850~859μg/g)、Sc(51~52μg/g) 含量和低的SiO2 (42.88%~44.90%)、Al2O3(11.53%~11.57%)、MgO (5.15%~5.29%, Mg#=0.32)、K2O (0.48%~0.51%)、Cr(< 2μg/g)和Ni(< 30μg/g) 含量及高的Ti/Y(1046~1106)、Ti/Zr(250~263) 比值为特征, 类似于Skaergaard侵入体.这些辉绿岩相对富集Rb、Th、U、Pb、Ti和轻稀土元素, 而相对亏损Ba、Sr、P和Nb、Ta.εNd(t) (-6.43~-4.12)、εSr(t) (42.94~64.19) 显示Sr-Nd同位素组成较为均匀, 并反映它们源于富集岩石圈地幔.认为长茂河子辉绿岩形成于富集岩石圈地幔的部分熔融, 经历了岩浆结晶分异与地壳混染作用.高铁钛辉绿岩和低高铁钛辉绿岩形成环境不同, 前者形成于相对低氧逸度或相对封闭的结晶环境中.   相似文献   

7.
Trace amounts of three halogens (chlorine, bromine and iodine) in seventeen U.S. Geological Survey (USGS) geochemical reference materials were determined by radiochemical neutron activation analysis (RNAA). The materials analysed were AGV‐2 (andesite), BCR‐2, BHVO‐2 and BIR‐1a (basalts), CLB‐1 (coal), COQ‐1 (carbonatite), DGPM‐1 (disseminated gold ore), DNC‐1a (dolerite), DTS‐2b (dunite), GSP‐2 (granodiorite), Nod‐A‐1 and Nod‐P‐1 (manganese nodules), QLO‐1a (quartz latite), SBC‐1 (marine shale), SDC‐1 (mica schist), SGR‐1b (shale rock) and W‐2a (diabase). The chlorine, bromine and iodine contents were determined to be 5.64 mg kg?1 (BIR‐1a) to 4410 mg kg?1 (Nod‐A‐1), 0.039 mg kg?1 (BIR‐1a) to 52.1 mg kg?1 (CLB‐1), and 0.041 mg kg?1 (BIR‐1a) to 599 mg kg?1 (CLB‐1), respectively. The RNAA data of the three halogens were compared with the corresponding data in the literature.  相似文献   

8.
张麻井铀钼矿床是中国北方最大的与火山岩有关的热液铀矿床,围岩蚀变广泛发育,其中黄铁矿化在该矿床分布虽 较为局限,但是与铀钼成矿关系密切。为了研究黄铁矿化蚀变与铀、钼成矿的亲缘关系,文章对张麻井的黄铁矿化蚀变岩 进行主、微量元素分析,并选择Yb作为不活动组分,使用质量平衡迁移计算方法, 利用Grant公式对其组分迁移进行定量 计算。岩石地球化学特征显示,黄铁矿化蚀变岩的TFeO含量极高,介于11.24%~24.57%之间(平均18.45%),其中Fe2O3含量 10.78%~25.25% (平均18.64%)、FeO含量1.43%~1.90% (平均1.69%),Fe2O3/FeO比值平均为10.99,有可能受到后期氧 化。黄铁矿化蚀变岩在Isocon图解上等浓度线斜率小于1,表明整体发生了组分的带入,带入的主要组分为大量的TFeO (131倍),成矿元素Mo(884倍)、Pb(11倍)、U(4.9倍)、V(2.8倍)、Ta(0.44倍)、Cu(0.64倍),碱金属Na2O(0.45 倍),以及Cd(424倍)、Bi(13倍) 等;带出的主要组分有碱金属Li(-0.73)、K2O(-0.17),成矿元素Zn(-0.38)、Cr (-0.37),以及Eu(-0.58)、Sc(-0.25) 等。其中SiO2略微减少(-0.03),带入的Mo含量远大于U的含量,据此认为黄铁 矿化与钼成矿关系更为密切。  相似文献   

9.
张麻井铀钼矿床是中国北方最大的与火山岩有关的热液铀矿床,围岩蚀变广泛发育,其中黄铁矿化在该矿床分布虽 较为局限,但是与铀钼成矿关系密切。为了研究黄铁矿化蚀变与铀、钼成矿的亲缘关系,文章对张麻井的黄铁矿化蚀变岩 进行主、微量元素分析,并选择Yb作为不活动组分,使用质量平衡迁移计算方法, 利用Grant公式对其组分迁移进行定量 计算。岩石地球化学特征显示,黄铁矿化蚀变岩的TFeO含量极高,介于11.24%~24.57%之间(平均18.45%),其中Fe2O3含量 10.78%~25.25% (平均18.64%)、FeO含量1.43%~1.90% (平均1.69%),Fe2O3/FeO比值平均为10.99,有可能受到后期氧 化。黄铁矿化蚀变岩在Isocon图解上等浓度线斜率小于1,表明整体发生了组分的带入,带入的主要组分为大量的TFeO (131倍),成矿元素Mo(884倍)、Pb(11倍)、U(4.9倍)、V(2.8倍)、Ta(0.44倍)、Cu(0.64倍),碱金属Na2O(0.45 倍),以及Cd(424倍)、Bi(13倍) 等;带出的主要组分有碱金属Li(-0.73)、K2O(-0.17),成矿元素Zn(-0.38)、Cr (-0.37),以及Eu(-0.58)、Sc(-0.25) 等。其中SiO2略微减少(-0.03),带入的Mo含量远大于U的含量,据此认为黄铁 矿化与钼成矿关系更为密切。  相似文献   

10.
内蒙古海拉尔盆地大磨拐河组孢粉组合   总被引:13,自引:1,他引:13  
海拉尔盆地大磨拐河组自下而上可以划分出两个孢粉组合 :哈氏三角孢 -微细云杉粉 ( Deltoidospora hallii-Piceaepollenites exilioides)组合和澳洲无突肋纹孢 -卵形光面单缝孢 ( Cicatricosisporites australiensis- L aevigato-sporites ovatus)组合 ,分别分布于大磨拐河组一段和二段 ,组合特征明显 ,可以作为研究区内地层划分对比的生物地层学依据之一。两个孢粉组合中见有属种繁多的海金沙科孢子及其他繁盛于早白垩世的孢子花粉 ,结合在数以千计的岩心样品中没有发现可靠的早期被子植物花粉的情况分析 ,推测产这两个孢粉组合的大磨拐河组的地质时代为早白垩世凡兰吟期—欧特里沃期 ( Valanginian— Hauterivian) ,不排除部分进入巴列姆期 ( Barrem ian)的可能  相似文献   

11.
This paper describes the occurrence and significance of hydrocarbons present in two bituminous marl layers and one distinct gypsum layer from a Messinian sedimentary basin, where hypersaline conditions prevailed. Several new compounds were detected and tentatively identified: of these 20R and 20S 4α, 24-dimethyl-5α(H),14β(H),17β(H) and 20R and 20S 4β,24-dimethyI-5α(H),14β(H),17β(H) cholestanes; 4-methylspirosterenes; 4,4-dimethyl-5α(H),14β(H),17β(H) pregnanes and homopregnanes are discussed in this paper. Several of these compounds might be considered as biological markers for a (hyper)saline environment. The short side chain 4-desmethylsteranes, 5α(H),14β(H),17β(H), 5α(H),14β(H),17α(H) and 5α(H),14α(H), 17α(H) pregnanes and homopregnanes, are the most abundant compounds in the extract from the gypsum sample. It is suggested that in this case these compounds do not reflect the stage of diagenesis but are related to certain organisms exclusively occurring in hypersaline environments. In addition the very low pristane/phytane ratio, often considered as an indicator for anoxicity, could also be interpreted as a useful indicator for hypersalinity.  相似文献   

12.
The authors develop an integrated method using geochemistry and micromorphology to examine the use of archaeological features at Dust Cave, a Paleo‐Indian through Middle Archaic (10,650–3600 cal. B.C.) site in northwest Alabama. Samples analyzed using ICP‐AES for aluminum (Al), barium (Ba), calcium (Ca), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), sodium (Na), phosphorous (P), strontium (Sr), sulfur (S), and zinc (Zn) and suggest that cultural features differ chemically from geogenic sediments in several ways: (a) K‐means cluster analyses indicate that features of known origin and suspected features of the same origin cluster together, thereby allowing for a preliminary separation into discrete functionalities; (b) phosphorus serves as an indicator of human occupation intensity; and (c) Sr/Ca and K/P ratios help identify anthropogenic materials. Micromorphological observations allow for a finer subdivision of feature types and help highlight postdepositional processes affecting cave sediments, and interpretation of activity at the site. These findings show that feature diversity and occupation intensity increased through time, peaking during the Middle Archaic. © 2006 Wiley Periodicals, Inc.  相似文献   

13.
Lal. Kumar  Joshi  G.  Agarwal  K. K. 《Geotectonics》2020,54(3):410-427
Geotectonics - Study of morphometric parameters such as stream length (Lu) and stream length ratios (Rl), bifurcation ratio (Rb), drainage density (D), form factor (Rf), circularity ratio (Rc),...  相似文献   

14.
为了解周边国家的地质构造特征,经实地调研与前人资料整理,将缅甸构造单元边界确认为9条断裂.即:那加山-若开山逆冲断裂(F1)、平梨铺-卑谬伸展断裂(F2)、实皆-勃固右行平移断裂(F3)、葡萄-格杜逆冲断裂(F4)、英昆-八莫伸展断裂(F5)、南坎-抹谷右行平移断裂(F6)、曼德勒-垒固左行平移断裂(F7)、锡当-三塔左行平移断裂(F8)、孟宾-清迈逆冲断裂(F9).这9条断裂构成钦邦-若开邦结合带(E-N1)(Ⅰ1)、西克钦邦结合带(E-N1)(Ⅰ2)、蒙育瓦-勃生岛弧带(E-N1)(Ⅱ1)、瑞保-仰光弧后盆地(E-N1)(Ⅱ2)、密支那岛弧带(E-N1)(Ⅱ3)、八莫陆缘弧(T3-K)(Ⅲ1)、毛淡棉陆缘弧(T3-K)(Ⅲ2)、德林依达地块(Pz2)(Ⅲ3)、保山-掸邦陆块(C-T2)(Ⅳ)、昌宁-孟连-清莱结合带(C-T2)(Ⅴ)10个一级、二级大地构造单元的边界.  相似文献   

15.
中国铁矿成矿地质特征和资源潜力   总被引:6,自引:1,他引:6  
中国铁矿主要分为七大类型时常同积变质型磁铁-赤铁矿床,基性侵入体岩型钡钛磁铁矿床,矽卡岩型磁铁矿床,火山岩型磁铁-赤铁矿床,沉积型赤铁-菱铁矿床,多因复合-迭加型磁铁-赤铁矿床,风化淋滤褐铁-赤铁矿床。  相似文献   

16.
Flash floods are responsible for loss of life and considerable property damage in many countries.Flood susceptibility maps contribute to flood risk reduction in areas that are prone to this hazard if appropriately used by landuse planners and emergency managers.The main objective of this study is to prepare an accurate flood susceptibility map for the Haraz watershed in Iran using a novel modeling approach(DBPGA) based on Deep Belief Network(DBN) with Back Propagation(BP) algorithm optimized by the Genetic Algorithm(GA).For this task, a database comprising ten conditioning factors and 194 flood locations was created using the One-R Attribute Evaluation(ORAE) technique.Various well-known machine learning and optimization algorithms were used as benchmarks to compare the prediction accuracy of the proposed model.Statistical metrics include sensitivity,specificity accuracy, root mean square error(RMSE), and area under the receiver operatic characteristic curve(AUC) were used to assess the validity of the proposed model.The result shows that the proposed model has the highest goodness-of-fit(AUC = 0.989) and prediction accuracy(AUC = 0.985), and based on the validation dataset it outperforms benchmark models including LR(0.885), LMT(0.934), BLR(0.936), ADT(0.976), NBT(0.974), REPTree(0.811), ANFIS-BAT(0.944), ANFIS-CA(0.921), ANFIS-IWO(0.939), ANFIS-ICA(0.947), and ANFIS-FA(0.917).We conclude that the DBPGA model is an excellent alternative tool for predicting flash flood susceptibility for other regions prone to flash floods.  相似文献   

17.
基于可拓评判法的黑土肥力质量评价   总被引:1,自引:0,他引:1  
根据黑土肥力的实验特点及前人研究成果,选取与养分和理化性质相关的10个评价指标,包括有机质(SOM)、全氮(TN)、速效磷(AP)、速效钾(AK)、阳离子交换量(CEC)、酸碱度(pH)、容重(BD)、黏粒(CP)、>0.25mm水稳性团聚体(WSA>0.25)和分散率(DR),通过这些指标建立了新的黑土肥力质量评价体系。以该评价体系为参照,采用主成分分析法确定权重,运用可拓学理论对吉林省农业黑土的肥力质量进行综合评判。结果表明:WSA>0.25、BD和AP 3项指标权重最大,说明黑土肥力的主要限制因子可能为土壤的物理性质及有效磷肥含量;吉林省农业黑土的肥力质量以中等为主,占整个样品数的73%。  相似文献   

18.
This study addresses a framework to evaluate and map environmental hazard with reference to spatial distribution of major and trace metal contamination and its relationship with lithology in Chandrapur district of Maharashtra, India using geospatial, statistical and GIS tools. In all, 208 ground water and 35 surface water samples were collected using global positioning system (GPS) synoptically with satellite imagery IRS P6 LISS III and were analyzed in ICP-AES. Analytical results reflect the presence of major and trace metals in ground water in terms of % as Fe (48%), Mn (12%), Zn (9%), Al (8%), Pb (7%), Cu (6%), Ni (4%), Cd (3%) and Cr (3%) of the total average concentration. The contamination is attributed to weathering of rocks and also to mining activities. Similarly, surface water contribution of major and trace metals was found as Al (47.8%), Fe (42.8%), Mn (5.5%), Zn (2.3%), Pb (0.56%), Ni (0.42%), Cu (0.16%), Cr (0.16%) and Cd (0.10%) of the total average concentration. Ordinary kriging interpolation method was adopted to assess the spatial distribution of different major and trace metals in groundwater samples with their best model fit variogram Classical statistical method like principal component analysis (PCA) was carried out in order to establish correlation between spatial pattern of metal contamination and geology of the area in GIS environment. Various surface and subsurface aspects like landuse/land cover, structural features, hydrogeology, topography etc were also considered to ascertain their impact to supplement the inference of the study.  相似文献   

19.
The composition of accessory minerals from granites of the second phase, quartz-muscovite (+fluorite), and quartz-muscovite-topaz greisens from the Primorsky rapakivi granite complex, West Baikal region, were studied using backscattered scanning electron microscopy. Ilmenite from granites contains inclusions of cassiterite, titanocolumbite, fergusonite-(Y), polycrase-(Y), and betafite. Allanite-(Ce), bastnaesite-(Ce), xenotime-(Y), Y- and Zr-thorite, zircon, and cyrtolite have been identified in granites. Greisens contain cassiterite, ferrocolumbite (Ta/Nb = 0.02−0.06), pyrochlore-group minerals, ilmenorutile, rutile, wolframite, polycrase-(Y), monazite-(Ce), fluocerite-(Ce), bastnaesite-(Ce), cerphosphorhuttonite, thorite, and other minerals. The ferrocolumbite + ilmenorutile assemblage is typical of quartz-muscovite greisen, whereas the rutile + ilmenorutile + wolframite + W-columbite assemblage is contained in the quartzmuscovite-topaz greisen as a result of an increase in Eh and decrease in pH and potassium activity of solution in the back zone. The compositions of Th- and REE-bearing minerals indicate the important role of phosphate and fluorine complexes in the transport of these elements.  相似文献   

20.
通过对大别造山带前陆北淮阳地区石炭纪高煤级煤的X射线荧光光谱分析,探讨了不同变形-变质类型煤中常量元素的分布规律及其影响因素。结果表明:构造-热作用具有使Al3+、K+、Si4+、Ti4+在煤体中富集,P5+、Fe2++Fe3+、Mn2+Na+、Ca2+、Mg2+向煤体外迁移的趋势;在弱应力带富集Al3+、K+、Ti4+、Na+、Ca2+;在强应力带富集Si4+、P5+、Fe2++Fe3+、Mg2+。岩浆热变质类型煤和构造-热变质类型煤的w(SiO2)/w(Al2O3)和w(K2O)/w(Na2O)值显著增大,与岩浆岩中SiO2及K2O质量分数偏高有重要的成因联系。   相似文献   

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