世界海相钾盐矿床特征定量化分析及其意义

通过对世界26个主要的海相钾盐矿床进行详细的特征描述和定量化分析,获得了较为完善的海相钾盐矿床的特征参数值。结果表明钾矿区面积占盆地面积4.47%、矿区含矿密度为1.616×106 t/km2、盆地含矿密度值为0.045×106 t/km2、钾盐层最大厚度与总盐层最大厚度的比值为7.2%;按构造类型分类,相对活动区盆地含有最丰富的钾盐资源量,其矿盆比为6.87%、矿区含矿密度值是5.068×106 t/km2、盆地含矿密度值为0.063×106 t/km2、钾/总盐值为12.27%,其中后三项特征参数值在盆地构造类型中均属最大。讨论了世界海相钾盐矿床定量化研究的意义,不同类型钾盐矿床的特征参数有助于对我国海相盆地成钾条件研究,并可以对海相盆地中未发现钾资源储量进行远景预测与评估。     

陕西省旬阳县甘沟铅锌矿地质特征及成因

通过对甘沟铅锌矿的地质矿产勘查,已初步查明区内铅锌矿含矿层位为下志留统梅子垭组,圈定了4条铅锌矿体,已获铅锌矿资源量9.78×10^4t。该含矿层矿体单个长180-580 m,平均厚度1.22-1.79 m,平均锌品位5.42%-8.37%,平均铅品位1.93%-11.04%。认为该矿床成因属沉积-变形变质热液改造型矿床。     

2011年全球发现的新矿物种

在系统梳理2011年度全球发现并经国际矿物学协会(IMA)新矿物与矿物分类命名专业委员会(CNMNC)批准的122个新矿物种资料的基础上,从矿物名称、晶体化学式、晶系和空间群、晶胞参数、主要粉晶数据、物理性质、光学性质、产地与产状、与其他矿物种的关系、矿物名称来源、化学反应和光谱学特征等方面归纳总结了这些新矿物的重要矿物学特征。并按照中国新矿物及矿物命名专业委员会颁布的《矿物种汉名审订条例》,对122个新矿物种的中文名称进行了审订。通过适时公布国际新矿物工作的新进展和新成果,并逐步完善和规范矿物种中文译名体系,为我国新矿物的发现和研究提供有科学价值的参考和借鉴,不断推动矿物种中文译名规范化与标准化的进程。     

山东省昌邑市南任铁矿地质特征及成因初探

南任铁矿床位于莱州-安丘铁成矿带西北部,对其矿床成因认识存在较多争议。矿区内地层广布,构造、岩浆岩不发育。铁矿体呈透镜状产于滹沱纪粉子山群小宋组的底部层位,无穿插或交代围岩现象;围岩蚀变以蛇纹石化、绿泥石化为主,愈近矿体矿化蚀变愈强。矿石矿物以磁铁矿为主,少量黄铁矿、黄铜矿;脉石矿物主要为蛇纹石、绿泥石。矿石的结构构造主要为浸染状构造,半自形—他形粒状结构。岩矿石稀土元素含量表明磁铁矿主要为火山深成岩浆结晶分异形成,部分与火山沉积作用有关;磁铁矿化学成分特征也反映了这一点,综合认为其成因可能属海相火山岩型之火山岩浆-热液和火山沉积复合类型。在此基础上,总结了莱州-安丘铁成矿带上不同成因铁矿床的分布规律,为今后该地区铁矿勘查指明了方向。     

山东省东平汶上地区铁矿矿床成因探讨

山东省东平-汶上铁矿成矿带是鲁西重要的成矿带,区内已发现李官集、彭集等多个大中型铁矿床,探明了铁矿石资源量超过12亿t。通过收集东平-汶上地区基础地质调查、区域重磁、矿产勘查、科研成果等资料,分析了区内地层、构造、岩浆岩及区域航磁异常特征、重力异常特征与铁矿床的对应耦合关系,提出了矿床的3个控矿因素:即控矿地层(泰山岩群雁翎关组、山草峪组,地层控矿专属性)、控矿构造(同斜复式背斜构造)、控矿岩浆岩(改造和破坏了铁矿带的完整性),通过对成矿区带样品采集测试,分别从主量元素、稀土元素、微量元素、原岩恢复、变质岩构造背景等方面进行系统分析对比,探讨了该区铁矿床为海相岛弧火山——沉积变质成因。     

Secular light curve of 2P/Encke, a comet active at aphelion

We present the secular light curve of Comet 2P/Encke in two phase spaces, the log plot, and the time plot. The main conclusions of this work are: (a) The comet shows activity at perihelion and aphelion, caused by two different active areas: Source 1, close to the south pole, active at perihelion, and Source 2, at the north pole, centered at aphelion. (b) More than 18 physical parameters are measured from the secular light curves, many of them new, and are listed in the individual plots of the comet. Specifically we find for Source 1 the location of the turn on and turn off points of activity, RON=−1.63±0.03 AU, ROFF=+1.49±0.20 AU, TON=−87±5 d, TOFF=+94±15 d, the time lag, LAG(q)=6±1 d, the total active time, TACTIVITY=181±16 d, and the amplitude of the secular light curve, ASEC(1,1)=4.8±0.1 mag. (c) From this information the photometric age and the time-age defined in Ferrín [2005a. Icarus 178, 493-516; 2006. Icarus 185, 523-543], can be calculated, and we find P-AGE = 97 ± 8 comet years and T-AGE = 103 ± 9 comet years (cy). Thus Comet 2P/Encke is an old comet entering the methuselah stage (100 cy < age). (d) The activity at aphelion (Source 2), extends for TACTIVITY=815±30 d and the amplitude of the secular light curve is ASEC(1,Q)=3.0±0.2 mag. (e) From a new phase diagram an absolute magnitude and phase coefficient for the nucleus are determined, and we find RNUC(1,1,0)=15.05±0.14, and β=0.066±0.003. From this data we find a nucleus effective diameter DEFFE=5.12(+2.5;−1.7) km. These values are not much different from previous determinations but exhibit smaller errors. (f) The activity of Source 1 is due to H₂O sublimation because it shows curvature. The activity of Source 2 might also be due to H₂O due to the circumstantial situation that the poles point to the Sun at perihelion and aphelion. (g) We found a photometric anomaly at aphelion, with minimum brightness between +393 and +413 days after perihelion that may be an indication of topography. (h) We have re-reduced the 1858 secular light curve of Kamel [1991. Icarus 93, 226-245]. There are secular changes in 7 physical parameters, and we achieve for the first time, an absolute age calibration. We find that the comet entered the inner Solar System and began sublimating in 1645±40 AD. (i) It is concluded that the secular light curve can place constraints on the pole orientation of the nucleus of some comets, and we measure the ecliptic longitude of the south pole of 2P/Encke equal to 213.2±4.5°, in excellent agreement with other determinations of this parameter, but with smaller error. (j) Using the observed absolute magnitude of 1858 and 2003 and a suitable theoretical model, the extinction date of the comet is determined. We obtain ED=2056±3 AD, implying that the comet's lifetime is 125±12 revolutions about the Sun after entering the inner Solar System.     

中国地裂缝的发育特征及成因机制研究 ——以汾渭盆地、河北平原、苏锡常平原为例

地裂缝的发育特征及成因机制研究是正确认识地裂缝的关键一环,也是科学防灾减灾的必要前提。本文吸收了汾渭盆地、河北平原、苏锡常平原在近年里涌现出的一系列重要成果,并以这三地为例,分析总结了中国地裂缝的发育特征和成因机制。文章最后还对地裂缝分析研究方法的最新进展进行了梳理和介绍。研究结果表明:①中国地裂缝以汾渭盆地、河北平原以及苏锡常平原的最为典型,三地地裂缝的空间分布受地质构造和古地理因素作用和影响,各具特点;②中国地裂缝的形成发育既受控于地质条件,又与抽水活动动态响应,不同成因的地裂缝在几何形态上具有不同表现;③"断层蠕滑"和"抽水活动"是主导中国地裂缝形成的最基本和最重要的两种动力条件,相应的两种成因机制分别在构造活动较强的地区和地下水超采的地区应用良好。     

Preliminary study on enamel microstructure of Yuanmou Miocene hominoids of China

Late Miocene hominoid fossils found in Yunnan Province, China are of great importance in exploring hominid origins and hominoid phylogeny, and in recent years palaeoanthropologists have been paying great attention to them. The Yuanmou hominoid site is on…     

鄂尔多斯盆地北部奥陶系碳酸盐岩层序地层研究

碳酸盐岩的物源性质、形成背景、沉积机理和扩散方式都与碎屑岩有很大的差异．对于碳酸盐岩层序地层，需要从成因上、从台地的性质与演化、海不的进退、台地的淹没与暴露等方面进行研究．在总结露头层序地层工作方法的基础上，阐述了密集段、首次洪泛面和层序边界的识别标志，建立了高分辨率层序地层格架．鄂尔多斯盆地早奥陶世三道坎组沉积时，为碳酸盐岩－碎屑岩混合缓坡背景；桌子山组及克里摩里组沉积时为镶边陆架与末端陡倾缓坡的背景；乌拉力克组及中奥陶世时，转化为拗拉槽背景．由此分别建立了碳酸盐岩－碎屑岩缓坡模式和镶边陆架与末端陡倾缓坡的综合模式     

深源与浅源气体震前异常变化的差异性

本文根据１９９３年６月至１９９４年１月滇西及其邻近地区数次中强以上地震前ＣＯ２，Ｎ２，Ａｒ，Ｒｎ等气体组分释放动态的观测结果，研究了气体的物质迁移对其前兆异常变化的影响，发现深，浅源气体的震前趋势性异常释放和短临突跳异常的发生时间具有明显的有序性，基本模式是源自深部的气体组分的震前异常变化总是上先于浅源气体，这种现象在强震发生前更为明显。作者认为，导致深一浅源气体异常变化有序发生的原因与气体物质迁