凡口铅锌矿床地球化学特征及成矿作用分析

凡口铅锌矿床是发育于碳酸盐岩建造中的海底热泉喷溢沉积矿床,以“一大二富三集中”的特点和典型的地质地球化学特征吸引着中外矿床地质工作者。常量元素和矿化元素的分布、矿物包裹体特征、稀土元素组成和硫同位素组成反映出该矿床与外生作用有关。铅同位素组成具有壳源和地下地壳来源铅的特征,矿物包裹体水氢、氧同位素组成表明,成矿溶液可能与深层建造水有关,后期与大气降水有关。矿区主要矿层经历海底热泉喷溢沉积－成岩的演     

凡口铅锌矿床海底热泉喷溢成矿的地质地球化学特征

凡口铅锌矿是发育于海相碳酸盐岩建造中的海底热泉喷溢沉积矿床。在研究矿床地质特征和地球化学特征的基础上,总结了发育于同沉积断裂两侧的矿体的形态、产状,矿石组构,成矿元素、微量元素、稀土元素的组成与分布,成矿温度和流体的性质,提出了热泉成矿作用与海相碳酸盐沉积作用同时演化的结论。     

柞水银硐子银多金属矿床成因与成矿模式初步研究

氢氧同位素测定结果表明,成矿热水属深源热液性质,但在海底洼地成矿堆积时发生与海水的混合,使得成矿热液具有复合的特征。硫同位素分布直方图显示塔式效应不明显,显示出非单一来源的特征。铅同位素特征表明银硐子的铅来自地幔-下地壳。矿石与含矿地层的化学成分的比较也表明物质来源是不同的。热水大部分来自古海水下渗和下伏地层中的孔隙水(封存水)说明下伏地层亦是成矿物质的部分供给者。火山作用激发和强化了地壳内的热水循环萃取过程,同时也是银硐子矿床形成的强烈且稳定的动力系统。成矿物质来源于火山喷溢和热卤水。矿床产出受中泥盆统地层层位的严格限定,具同生沉积成因特征。同生断裂的演化,既是沉积盆地的主宰者,又沟通了地壳上部与更深处的成矿物质的交流,是银硐子矿床的主要控矿条件。矿床成因类型为:"火山-热卤水喷溢-同生沉积矿床"。并据此建立了该矿床的成矿模型。     

商县铁炉子金铅锌矿床稳定同位素研究

本文通过铁炉子金铅锌矿床硫、氢、氧、碳、铅同位素组成及矿床地质特征的研究,讨论了成矿地质环境和物理化学环境,成矿物质来源和成矿机理。认为该矿床属“海底流体下渗循环热液沉积改造”成因。     

粤北地区辉绿岩的特征及其地质意义

摘要：粤北地区辉绿岩脉发育于下石炭统顶界以下的地层中,与层控硫化物矿体伴生。辉绿岩化学成分、稀土元素组成和稳定同位素组成均具深源岩浆岩特点,侵位于早石炭世末期或中石炭世早期。辉绿岩的侵位是本区地壳运动性质发生变化、断裂系统由较浅层次向较深层次转化的结果,同时也是同沉积断裂作用及海底喷溢沉积成矿活动结束的信号     

贵州瓮福新元古代陡山沱期磷矿床铅同位素特征及来源探讨

贵州新元古代陡山沱期瓮福磷矿下矿层条纹-条带状磷块岩的磷条带、泥岩条带、上矿层磷块岩的磷质、白云质胶结物有各自不同的铅同位素组成特点。在Zartman铅构造模式图解中，下矿层磷条带和泥质磷块岩条带位于地幔铅、造山带铅和上地壳演化线之间，并呈很好的线性关系。上矿层块岩的白云质胶结物远离所有类型铅的演化线。下矿层的泥岩条带位于幔源铅和上志壳铅演化线之间，但与磷质不同，更偏向于白云质胶结物的分布区。在朱炳泉等（1998）的△γ-△β铅来源分类图上，上矿层和下矿层的甩磷质样品分布于地幔铅、上地壳与地幔混合俯冲带碎屑沉积作用铅和海底热水作用铅区。上矿层磷块岩的白云质胶结物分布于上地壳和地幔混合俯冲带岩浆作用铅、化学沉积型和海底热水作用型铅区。泥岩条带分布于地幔源和海底热水作用型铅区。因此，瓮福磷矿磷质样品的铅主要具地幔铅、上地壳铅和热水沉积作用的混合来源，以地幔为主。上矿层白云质胶结物铅同位素具有海源和海底热水作用的混合来源。下矿层泥岩条带铅同位素具地幔、上地壳和海源铅的混合特点。陡山沱期大规模磷质成矿的初始物质主要来源于地幔，预示着磷质的超常成矿与磷质生物的爆发可能与地幔体制的变化有某种成因联系。     

朝鲜检德矿田地质特征

文章总结了朝鲜检德矿田的区域地质特征、控矿层位、控矿构造及矿床特征,通过对矿床的同位素、包裹体特征及硅质岩特征的研究,提出检德矿床同生沉积和后期褶皱及变质作用改造重就位这两个阶段,层控特征明显,属于海底喷气(流)沉积变质型矿床。     

陕西柞水银洞子银,铅多金属矿床物质来源初探

银洞子矿床位于陕西省南部柞水县境内,是一个以银—铅为主的多金属矿床。矿区内钠长石、碧玉和重晶石条带很发育,岩石碎屑似凝灰质结构,矿带中可见凝灰岩出露。硫同位素以富集重硫为特征,δ~(34)S‰主要集中在2‰—20‰,其形态呈波浪式分布,矿石中的铅组成属正常铅,具有单阶段演化特征。矿石中和凝灰岩中的Rb/Sr值小于1,而Ag含量却相反,都大于1,即Ag含量和凝灰岩具有密切关系。其矿床特征可与麦根矿床、芒特艾萨矿床、霍各乞矿床等国内、外著名的火山成因矿床类比。笔者认为银洞子银、铅多金属矿床的矿质来源于海底火山喷溢。     

粤北地区辉绿岩的特生及其地质意义

粤北地区辉绿岩脉发育于下石炭统顶界以下的地层中，与程控硫化物矿体伴生。辉绿岩化学成分、稀土元素组成和稳定同位素组成均具深源岩浆岩特点，侵位于早石炭世末期或中石炭世早期。辉绿岩的位是本区地壳运动性质发生变化、断裂系统的由较浅层次向较深层次转化的结果，同时也是同沉积断裂作用及海底喷溢沉积成矿活动结束的信号。     

甘肃桦树沟（铁）铜矿床成因的地球化学制约

矿石及含矿岩系的稀土元素、微量元素、稳定同位素、流体包裹体以及同位素年代学等地球化学研究表明,桦树沟（铁）铜矿床形成于近大陆边缘的海底裂谷环境,成矿物质主要来自元古宙基性火山岩,硫、碳主要来自海水。火山一沉积岩系经深循环水一热系统的作用,成矿物质被浸出和搬运,并经海底喷溢作用沉淀于海盆洼地中形成含矿层,后期变质作用使成矿物质活化、转物和富集。矿床成因为喷气（流）沉积,变质改造型（铁）铜矿床。     

Chemical composition of wet precipitation at a developing urban site in southeastern China

A comprehensive study on the chemical composition of wet precipitation was carried out from January 2004 to December 2004 at Jinhua, China. All samples were analyzed for pH, electrical conductivity and major ions （F, Cl, NO3,. SO4^2-, K^＋, Na^＋, Ca^2＋, Mg^2＋. and NH4^＋）. The results showed that SO4^2- is one of the dominant anions, accounting for 66.1% of the measured anions in precipitation, while NH4^＋ and Ca^2＋ account for 56.6% and 33.4% of the measured cations, respectively. Even though the concentrations of SO4^2- and NO3^- were not high relative to those in the northern areas of China, rainwater in the studied area is typically acidic with a volume-weighted mean pH of 4.54 due to the lack of neutralization in precipitation. The fractional acidity value suggested that about 76% of acid was neutralized by alkaline constituents. On the other hand, H^＋ showed no significant correlation with other ionic species, which indicates that its acidity might be attributed to the comprehensive effect of all the acidifying and neutralizing ions rather than one major ion in precipitation. A good correlation between Ca^2＋ and Mg^2＋, as well as between Na^＋ and Cl^-, indicated these ions are commonly of crustal and marine origin, respectively. Other relatively good correlations were observed between NH4^＋ and SO4^2-, Ca^2＋ and SO4^2-, Mg^2＋ and SO4^2-, Mg^2＋ and NO3^-, and Mg^2＋ and Cl^-. These results were attributed to the atmospheric chemical reactions of the acids H2SO4, HNO3 and HCl with alkaline compounds such as NH3 and/or carbonate materials. High enrichment factor of marine source for SO4^2-, Ca^2＋ and K^＋ indicated that large amounts of these ions came mainly from a non-marine source. Similarly, a high enrichment factor of soil for SO4^2-, NO3^- and CI also suggested that most of these ions did not come from soil source.     

Comparison of the compositions of crystalline aluminosilicate rocks and their minerals in a planar triangular projection

The problem of comparison of the composition of crystalline rocks with the composition of the constituent minerals of these rocks is considered. It is proposed to present the composition of rocks and the compositions of the constituent minerals in the form of a triangle on the plane. The experience of presentation of compositions in phase diagrams was taken as a basis for the construction. Analysis of the crystallochemical characteristics of clinopyroxenes and garnets has shown that three parameters are enough for depicting the compositions of these and other minerals. For this purpose, similar composition components of rocks and their minerals are summarized in molecular proportions and are plotted on the triangle DO-1/2(R₂O3)-XO₂, where DO = (MgO + CaO + FeO + MnO + NiO + ...) + 1/4(Na₂O + Al₂O₃) + 1/4(K₂O + Al₂O₃), 1/2(R₂O₃) = 1/2(Al₂O₃ + Fe₂O₃ + Cr₂O₃ + ...) - (1/4(Na₂O + Al₂O₃) + 1/4(K₂O + Al₂O₃)), and XO₂ = SiO₂ + TiO₂. The compositions of minerals are expressed as the sums of their components: Ol = Fo + Fa + Lar + Neph + ..., Px = Di + En + Wol + Ged + Gip + Jd + Eg + ..., Ga = Pyr + Gross + Alm + Spe + Ski + Knr + Mj + ..., etc. A step-by-step calculation algorithm is proposed, which permits evaluation of the contents of bi- and trivalent iron during probe microanalyses of garnets and pyroxenes. Comparison of the compositions of deep-seated rocks and their minerals shows their good consistency. The proposed schematic projection permits a visual comparison of the compositions of rocks with low contents of carbonates and water, from ultrabasic (e.g., dunites) to acid (e.g., granites) ones.     

Stable carbon isotope characteristics of different plant species and surface soil in arid regions

The stable carbon isotope composition in surface soil organic matter (δ¹³Csoil) contains integrative information on the carbon isotope composition of the standing terrestrial plants (δ¹³Cleaf). In order to obtain valuable vegetation information from the δ¹³C of terrestrial sediment, it is necessary to understand the relationship between the δ¹³C value in modern surface soil and the standing vegetation. In this paper, we studied the δ¹³C value in modern surface soil organic matter and standing vegetation in arid areas in China, Australia and the United States. The isotopic discrepancy between δ¹³Csoil and δ¹³Cleaf of the standing dominant vegetation was examined in those different arid regions. The results show that the δ¹³Csoil values were consistently enriched compared to the δ¹³Cleaf. The δ¹³Cleaf values were positively correlated with δ¹³Csoil, which suggests that the interference of microorganisms and hydrophytes on the isotopic composition of surface soil organic matter during soil organic matter formation could be ignored in arid regions. The averaged discrepancy between δ¹³Csoil and δ¹³Cleaf is about 1.71%in Tamarix L. in the Tarim Basin in China, 1.50% in Eucalytus near Orange in Australia and 1.22% in Artemisia in Saratoga in the United States, which are different from the results of other studies. The results indicate that the discrepancies in the δ¹³C value between surface soil organic matter and standing vegetation were highly influenced by the differences in geophysical location and the dominant species of the studied ecosystems. We suggest that caution should be taken when organic matter δ¹³C in terrestrial sediment is used to extract paleovegetation information (C₃/C₄ vegetation composition), as the δ¹³C in soil organic matter is not only determined by the ratio of C₃/C₄ species, but also profoundly affected by climate change induced variation in the δ¹³C in dominant species.     

海水及淡水养殖珍珠的物质组成

采用偏光显微镜、X射线粉晶衍射仪、傅利叶红外光谱仪、电子顺磁共振谱仪、拉曼光谱仪、原子吸收光谱仪等测定了淡水珍珠、海水珍珠及部分贝壳的矿物及化学组成.研究表明: 珍珠矿物组成单一, 主要由文石构成, 仅含少量球文石或方解石; 淡水珍珠明显富含Mn, 而海水珍珠中明显富含Na、K、Mg、Sr; 这种富集特征与淡水、海水中元素的富集特征相似.此外, 各颜色品种之间化学成分也存在微小的差异, 白色珍珠比有色珍珠更纯净, 所含铁、锰、铬等致色元素更低.紫色珍珠略富含Mg、Mn, 橙色者明显富含Fe, 而黑色海水珍珠的颜色可能与有机组分有关.      

新疆和田碧玉的结构特征与组成矿物成分分析

采用扫描电子显微镜、电子探针、X射线粉晶衍射、红外光谱、拉曼光谱等测试方法对新疆和田-于田县矿区产出碧玉的结构特征、组成矿物成分进行了测试与分析,得到新疆和田碧玉的典型显微结构为纤维交织结构。组成矿物颗粒呈纤维状、粒状交织排列,进而形成了其手标本细腻的质地与高韧度。和田碧玉为闪石质玉石,主要矿物成分为透闪石,并且含有铬铁矿、绿泥石、蛇纹石、辉石、磷灰石等杂质矿物,透闪石随铁含量的增加向阳起石过渡。     

风化型和含煤建沉积型高岭土的物质组成对比研究

我国高岭土资源丰富,矿床类型多,其中风化和含煤建造沉积型是两类比较重要的高岭土矿床,对这两类高岭土矿床化学组成,矿物组成及高岭石矿物学特征的异同点进行研究和探讨,其结果表明,风化高岭土的化学成分一般属硅高铝低型,钾含量偏高,钛含量低,铁含量则随成矿线岩和风化条件的不同波动范围大,矿物组成主要为结晶度较差的高岭石、水云线和石英,以及极少量的管状埃洛石,含煤建造沉积型高岭土一般属铝高硅低型,钾含量低,钛含量明显偏高,矿物组成简单,高岭石含量〉９５％,结晶度较好。     

The identification of 9-n-alkyl fluorene-9-ols in the Alberta oil sands

Homologous series of 9-n-alkyl fluorene-9-ols and their nuclear methylated derivatives have been detected in the Alberta oil sands and their structure identified by infrared, field ionization and capillary gas chromatography-mass spectrometry and by comparison with synthetic standards.     

关于大陆地壳化学组成研究中某些问题的讨论

结合作者对中国东部的研究,探讨有关大陆地壳化学组成研究中存在的若干问题,包括深部地壳组成的研究方法,上地壳组成,地壳化学成分横向不均一性和元素相容性等问题。     

长江水中悬浮物含量与矿物和化学组成及其地质环境意义

在2003～2007年间,在长江干流的25个水文站及主要支流的13个水文站系统采样,对悬浮物的含量及其矿物与化学组成系统地进行了测定。根据这些数据,对长江悬浮物的矿物和化学组成的时空变化及其地质与环境意义进行了系统研究。 本次所采样品中悬浮物含量平均值为256.5mg/L,在世界各大河中居于中等水平。悬浮物含量呈现大幅度的时空变化,与水流速度、径流量及泥沙供给情况的变化相对应,受河床坡度、降雨量、风化强度、侵蚀情况及人工活动等多种因素的影响。近年来,长江悬浮物含量逐渐下降,与上游的退耕还林和水库建设密切相关。特别是三峡水库工程引起泥沙在库区大量沉积,显著降低河水的悬浮物含量,导致其下游河段堤岸冲刷加剧,洞庭湖、鄱阳湖和长江口的沉积减少。这种变化带来的环境效应巨大,需要慎重评估和应对。 长江水中悬浮物主要由粘土矿物、碎屑硅酸盐矿物和碎屑碳硅酸盐矿物组成,并含有少量重矿物、氢氧化物和有机物。与黄河悬浮物矿物组成的对比研究表明长江流域的化学风化作用明显强于黄河流域,而物理侵蚀作用明显弱于黄河流域。由上游到下游,长江悬浮物中粘土和碎屑硅酸盐矿物逐渐增高,而碎屑碳硅酸盐逐步降低,与中下游地区气候变得湿热,化学风化变强的情况相对应。 与上地壳岩石平均值相比,长江悬浮物的SiO2、CaO、K2O 、Na2O含量较低,而TFe2O3含量较高,反映硅酸盐矿物化学风化过程中部分硅、钾、钠、钙的流失和铁的富集。与全球河流悬浮物和黄河悬浮物相比,长江悬浮物的SiO2、Na2O含量较低,反映长江流域的化学风化作用较强。与长江水系沉积物相比,长江悬浮物的SiO2、Na2O含量较低,而Al2O3、K2O 、MgO、TFe2O3较高,反映悬浮物比较富含粒度较小的粘土与铁质成分。从上游往下游,长江悬浮物中CaO、MgO含量逐渐降低,SiO2 含量逐步升高,与粘土矿物含量增高和碳酸盐含量降低的趋势相对应。 长江悬浮物中Co、Ni、Cu、Zn、Pb、Cd含量均高于上地壳岩石的平均含量,可能由这些元素在风化过程优先为粘土所吸附所引起。在攀枝花、宜宾、九江、大通、南京等站悬浮物中发现的铜、铅、锌的高含量,可能均与相关地段采矿活动有关。2005年7月在富顺和长沙发现Cd的高异常值引人注目。悬浮物中Cu、Pb、Zn、Cd的含量较长江水系沉积物的平均含量高出数倍、乃至数十倍,可能反映近年来流域采矿活动加剧,其对流域环境的长远影响值得关注。 长江悬浮物的稀土总量与全球页岩的平均值相比略显偏高。长江悬浮物的REE分布形式于上地壳基本一致,表明长江流域出露的岩石的化学组成与上地壳岩石平均组成没有明显差别,而且岩石风化过程中稀土元素未出现明显分馏。