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191.
FY-2B由于杂散光的影响,其可见光通道的发射前定标存在较大误差。利用敦煌戈壁滩辐射校正场可进行FY-2B可见光通道的在轨绝对定标。由于FY-2B对于敦煌场区的卫星天顶角接近50°,需要进行场地的方向特性BRDF修正。2002年7月对FY-2B进行了场地地表反射率、大气消光、探空等项同步测量,并对场地的方向特性进行了测量。资料处理结果表明,FY-2B可见光通道杂散光可影响定标精度达20%。长期监视表明FY-2B可见光通道探测器输出十分稳定。该文将4个可见光通道探测器场地定标得出的定标查找表列出,供用户参考使用。 相似文献
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194.
许多物化探及地质成果资料以纸质图件保存,在资料的再利用时需对其进行数字化.这里简要介绍一种数字化功能强大的矢量化软件-R2V的功能,针对物化探图件的特点,探讨了R2V数字化的流程. 相似文献
195.
铜陵地区老鸦岭层状钼矿床铅同位素组成研究 总被引:1,自引:0,他引:1
安徽铜陵老鸦岭矿床中二叠系大隆组(P2d)顶部的含矿(钼矿化)黑色页岩以及附近(立新煤矿)同一层位不含矿黑色页岩的实测铅同位素组成分别为:^206Pb/^204Pb20.20~22.37,^207Pb/^204Pb15.67~15.82,^208Pb/^204Pb38.47~38.60和^206Pb/204Pb18.83~20.80,^207Pb/^204Pb15.65~15.76,^208Pb/^204Pb38.84~39.22。对137Ma的放射成因Pb进行校正后的铅同位素组成表明,含矿黑色页岩和不含矿黑色页岩均与燕山晚期火成岩无关,老鸦岭含矿黑色页岩可能具沉积成因。对沉积(约250Ma)以来的放射成因Pb进行校正后的铅同位素组成表明:不含矿黑色页岩的Pb源自上地壳,而含矿黑色页岩的Pb(因而推测其他成矿金属)可能源于上地壳物质(与不含矿黑色页岩的Pb源相似)与下地壳物质的混合。 相似文献
196.
吉林台水电站厂房高边坡稳定性及加固措施研究 总被引:2,自引:0,他引:2
吉林台水电站厂房后边坡开挖形成140~340m的高边坡,保证其长期运行稳定性至关重要。在结合地质资料对边坡的失稳模式进行初步判断的基础上,采用极限平衡分析方法对正常蓄水、暴雨影响、地震荷载等工况条件下边坡的整体抗滑稳定性进行分析,得出暴雨对边坡稳定影响较大的结论,据此提出以排水结合预应力锚索为主的边坡加固增稳措施,实践证明该措施是有效的。 相似文献
197.
EWART A.; MARSH J. S.; MILNER S. C.; DUNCAN A. R.; KAMBER B. S.; ARMSTRONG R. A. 《Journal of Petrology》2004,45(1):59-105
The bimodal NW Etendeka province is located at the continentalend of the Tristan plume trace in coastal Namibia. It comprisesa high-Ti (Khumib type) and three low-Ti basalt (Tafelberg,Kuidas and Esmeralda types) suites, with, at stratigraphicallyhigher level, interstratified high-Ti latites (three units)and quartz latites (five units), and one low-Ti quartz latite.Khumib basalts are enriched in high field strength elementsand light rare earth elements relative to low-Ti types and exhibittrace element affinities with Tristan da Cunha lavas. The unradiogenic206Pb/204Pb ratios of Khumib basalts are distinctive, most plottingto the left of the 132 Ma Geochron, together with elevated 207Pb/204Pbratios, and SrNd isotopic compositions plotting in thelower 143Nd/144Nd part of mantle array (EM1-like). The low-Tibasalts have less coherent trace element patterns and variable,radiogenic initial Sr ( 相似文献
198.
The Solubility of Sulphur in Hydrous Rhyolitic Melts 总被引:1,自引:1,他引:1
Experiments performed at 2 kbar, in the temperature range 8001000°C,with fO2 between NNO2·3 and NNO+2·9 (whereNNO is the nickelnickel oxide buffer), and varying amountsof sulphur added to hydrous metaluminous rhyolite bulk compositions,were used to constrain the solubility of sulphur in rhyolitemelts. The results show that fS2 exerts a dominant control onthe sulphur solubility in hydrous silicate melts and that, dependingon fO2, a rhyolitic melt can reach sulphur contents close to1000 ppm at high fS2. At fO2 below NNO+1, the addition of ironto a sulphur-bearing rhyolite magma produces massive crystallizationof pyrrhotite and does not enhance the sulphur solubility ofthe melt. For a given fO2, the melt-sulphur-content increaseswith fS2. For fixed fO2 and fS2, temperature exerts a positivecontrol on sulphur solubilities, at least for fO2 below NNO+1.The mole fraction of dissolved sulphur exhibits essentiallylinear dependence on fH2S at low fO2 and, although the experimentalevidence is less clear, on fSO2 at high fO2. The minimum insulphur solubility corresponds to the redox range where bothfH2S and fSO2 are approximately equal. A thermodynamic modelof sulphur solubility in hydrous rhyolite melts is derived assumingthat total dissolved sulphur results from the additive effectsof H2S and SO2 dissolution reactions. The model reproduces wellthe minimum of sulphur solubility at around NNO+1, in additionto the variation of the sulphide to sulphate ratio with fO2.A simple empirical model of sulphur solubility in rhyoliticmelts is derived, and shows good correspondence between modeland observations for high-silica rhyolites. KEY WORDS: sulphur; solubility; rhyolite; thermodynamics; fO2; fS2 相似文献
199.
CLIFFORD TOM N.; BARTON ERIKA S.; STERN RICHARD A.; DUCHESNE JEAN-CLAIR 《Journal of Petrology》2004,45(4):669-691
The O'okiep Copper District is underlain by voluminous 10351210Ma granite gneiss and granite with remnants of metamorphosedsupracrustal rocks. This assemblage was intruded by the 1030Ma copper-bearing Koperberg Suite that includes jotunite, anorthosite,biotite diorite and hypersthene-bearing rocks ranging from leuconoriteto hypersthenite. New sensitive high-resolution ion microprobeage data demonstrate the presence of 17002000 Ma zirconas xenocrysts in all of the intrusive rocks, and as detritalzircon in the metasediments of the Khurisberg Subgroup. Thesedata are consistent with published SmNd model ages ofc. 1700 Ma (TCHUR) and c. 2000 Ma (TDM) of many of the intrusivesthat support a major crust-forming event in Eburnian (Hudsonian)times. In addition, UThPb analyses of zirconsfrom all major rock units define two tectono-magmatic episodesof the Namaquan Orogeny: (1) the O'okiepian Episode (11801210Ma), represented by regional granite plutonism, notably theNababeep and Modderfontein Granite Gneisses and the Concordiaand Kweekfontein Granites that accompanied and outlasted (e.g.Kweekfontein Granite) regional tectonism [F2(D2)] and granulite-faciesmetamorphism (M2); (2) the Klondikean Episode (10201040Ma), which includes the intrusion of the porphyritic RietbergGranite and of the Koperberg Suite that are devoid of regionalplanar or linear fabrics. Klondikean tectonism (D3) is reflectedby major eastwest-trending open folds [F3(D3a)], andby localized eastwest-trending near-vertical ductilefolds [steep structures; F4(D3b)] whose formationwas broadly coeval with the intrusion of the Koperberg Suite.A regional, largely thermal, amphibolite- to granulite-faciesmetamorphism (M3) accompanied D3. This study demonstrates, interalia, that the complete spectrum of rock-types of the KoperbergSuite, together with the Rietberg Granite, was intruded in ashort time-interval (<10 Myr) at c. 1030 Ma, and that therewere lengthy periods of about 150 Myr of tectonic quiescencewithin the Namaquan Orogeny: (1) between the O'okiepian andKlondikean Episodes; (2) from the end of the latter to the formalend of Namaquan Orogenesis 800850 Ma ago. KEY WORDS: UPb, zircon; O'okiep, Namaqualand; granite plutonism; granulite facies; Koperberg Suite; Namaquan (Grenville) Orogeny 相似文献
200.
Sensitive high-resolution ion microprobe UPb dating showsthat a biotite orthogneiss from the Hercynian belt of westerncentral Iberia contains 1000300 Ma zircon. Older, 1000570Ma ages within this range represent inherited, detrital materialamong which four age components may be recognized: 相似文献