高氯酸-盐酸体系-火焰原子吸收光谱法测定铅精粉中的银

采用X射线衍射技术(XRD)对水镁石原矿和不同工艺条件生产的出口镁砂产品进行了物相组成分析,水镁石原矿粉中主相Mg(OH)2含量达到85.9%,杂质主要是Mg3Si2(OH)4O5、CaCO3和CaMg(CO3)2;轻烧镁砂中的Mg(OH)2大部分已经分解为MgO,但还有12.3%的Mg(OH)2未分解,并在低温煅烧的情况下生成了微量的新相Mg2SiO4;重烧镁砂中的Mg(OH)2已经完全分解为MgO,杂质主要存在形式是Mg2SiO4和CaCO3,占总量的18.5%。实验结果将成为提高水镁石矿煅烧生产的镁砂品质而改进提纯工艺的参考依据。     

西藏蛇绿岩豆荚状铬铁矿中简单氧化物矿物组合及其超高压成因

最近在西藏罗布莎蛇绿岩豆荚状铬铁矿中,发现包括金刚石、柯石英和某些简单氧化物,诸如SiO2、MgO、Fe2O3、Cr2O3、Al2O3以及(Si,Ti)O2等组成的矿物群。这些矿物是非常复杂的由70~80种矿物组成的地幔矿物群的一部分。这充分证实在地幔中存在简单氧化物。高压-高温相平衡实验表明,硅酸盐矿物在下地幔条件才可分解成FeO、MgO和SiO2等简单氧化物(>670km)。因此有理由认为罗布莎简单氧化物可能来自下地幔深部。     

南海北部陆架海域表层沉积物地球化学特征及地质意义

依据南海北部陆架海域225个站位表层沉积物粒度和常量元素的地球化学分析,探讨了常量元素的空间分布规律及地质意义。该区域沉积物主要为粉砂、细砂等细粒沉积,平均粒径5.38。沉积物常量元素组合以SiO2、Al2O3、Fe2O3、MgO、CaO、Na2O、K2O为主,约占沉积物总量的87.96%,其空间分布特征与沉积物类型密切相关。Al2O3、Fe2O3、MgO、K2O、Org.C等分布趋势相似,具有较好的相关性,倾向于富集在细粒沉积物中;SiO2、CaO、CaCO3与大多数元素呈负相关,倾向于富集在粗颗粒沉积物中,反映了“元素的粒度控制律”。元素总体分布规律显示沉积物的常量元素含量受细粒黏土矿物吸附作用、石英矿物和碳酸钙稀释作用的共同影响。元素统计结果表明,表层沉积物的常量元素大体可分为2类：第1类包括Al2O3、Fe2O3、MgO、TiO2、P2O5、MnO等,代表陆源较细粒碎屑沉积,是控制研究区沉积物化学成分的最主要因素;第2类主要包括CaO、CaCO3,代表海洋生物沉积。同时可将研究区分为3个沉积区域：I沉积区为粤西近岸及北部湾北部区域,具有明显陆源碎屑沉积特征;Ⅱ沉积区位于粤西陆架水深＞60 m海域,受海源生物作用明显;Ⅲ沉积区位于珠江口西南部水深40～60 m海域,为斑块状砾质粗粒沉积。     

异极矿加热过程的研究

实验所用的两块异极矿标本采自云南金硕铅锌矿氧化带中。对样品进行了湿法化学全分析、差热分析和失重分析。实验结果表明,所研究的样品化学式与Zn4Si2O7(OH)2·H2O相符。根据以上分析结果,分别在600℃、700℃、800℃、 900℃和1300℃进行恒温三小时热处理,并对热处理过的样品进行X光粉晶衍射和红外吸收光谱分析。异极矿大约在500℃失去结晶水,在700℃失去氢氧根。在600℃时,X光粉晶衍射数据表明它的结构与异极矿没有本质差别,仅仅是晶胞微微缩小,此时红外光谱分析表明样品中有结构水存在,因此说明这种结构水是一种“沸石水”。这时的样品是Zn4Si2O7(OH)2,即脱水异极矿,而非γ-Zn2SiO4。700℃处理样品与Taylor实验中的β-Zn2SiO4有完全一致的X光粉晶衍射数据,但它不是单一物相,而是以锌橄榄石为主,并含有部分脱水异极矿和硅锌矿,β-Zn2SiO4的结构是橄榄石型的。800℃、900℃和1300℃热处理异极矿保持硅锌矿物相。总体来看,γ-Zn2SiO4并不存在,也不会分解成为ZnO和SiO2。     

下地幔温压下(Mg, Fe)SiO3钙钛矿的相稳定性

在69～100 GPa冲击压力(估算温度为2600～4300 K)范围内进行了初始样品为(Mg0.92, Fe0.08)SiO3顽火辉石和MgO+SiO2的冲击压缩回收实验。对回收样品进行的X射线衍射(XRD)分析结果表明: 两发顽火辉石回收样品的主相均是单链状结构硅酸盐, 而非钙钛矿结构; 另外, 回收样品中均未观察到氧化物SiO2 和(Mg0.92, Fe0.08)O的XRD特征谱线; 两发MgO+SiO2回收样品中均观察到SiO2和镁橄榄石(Mg2SiO4)而没有氧化物MgO。实验结果表明: 在冲击压缩过程中样品处于钙钛矿结构, 在冲击卸载过程中样品发生了由钙钛矿结构向单链状结构的逆转相变; 在实验的温压范围内, 不可能发生由(Mg0.92, Fe0.08)SiO3向SiO2和(Mg0.92, Fe0.08)O的化学分解相变, 顽火辉石的高压相——钙钛矿结构是稳定的。高压加载或卸载过程引起的晶格畸变导致回收样品和原始样品的谱线差异, 而高压加载导致钙钛矿型(Mg0.92, Fe0.08)SiO3晶格畸变的可能性更大。     

南黄海沉积物常量元素组成及物源分析

通过对南黄海295个站位沉积物样品的常量元素含量分析,研究了南黄海沉积物常量元素组成的R-型聚类分析、R-型因子分析及与物质来源的关系。南黄海沉积物常量元素Al2O3、MgO、K2O、Fe2O3分布基本相似;SiO2分布与Al2O3、MgO、K2O、Fe2O3分布相反;中、西部CaO、CaCO3分布与黄河、长江物源有明显关系;Na2O分布与黄河物质供给有关;TiO2分布反映了长江物质的运移方向。现代黄河物质及老黄河物质主要沉积于南黄海的西部、中部和东南部;海区东部物质反映来自朝鲜半岛物质的对南黄海东部的作用。长江物质主要局限于南黄海的西南和南部区域沉积;TiO2和Ti/Al分布反映了长江物质可能对南黄海中部区域也有所影响。     

南黄海沉积物常量元素组成及物源分析

通过对南黄海295个站位沉积物样品的常量元素含量分析,研究了南黄海沉积物常量元素组成的R-型聚类分析、R-型因子分析及与物质来源的关系。南黄海沉积物常量元素Al2O3、MgO、K2O、Fe2O3分布基本相似;SiO2分布与Al2O3、MgO、K2O、Fe2O3分布相反;中、西部CaO、CaCO3分布与黄河、长江物源有明显关系;Na2O分布与黄河物质供给有关;TiO2分布反映了长江物质的运移方向。现代黄河物质及老黄河物质主要沉积于南黄海的西部、中部和东南部;海区东部物质反映来自朝鲜半岛物质的对南黄海东部的作用。长江物质主要局限于南黄海的西南和南部区域沉积;TiO2和Ti/Al分布反映了长江物质可能对南黄海中部区域也有所影响     

磁铁矿中磁性物成分的测定及可选性评价

对磁铁矿样品分别用磁选管和手工内磁选法进行磁选,并对原矿样品和样品的磁性物中TFe、P、S、V2O5、TiO2、SiO2、Al2O3、CaO、MgO、Sn、Cu、Pb、Zn的含量进行测定.分析结果表明,采用手工内磁选和磁选管对磁铁矿进行磁选所得的结果一致,为了简便操作,本文均采用手工内磁选法选出磁性物.A矿区磁性铁(mFe)含量(22.42％)比B矿区mFe含量(22.59％)低,但A矿区样品的磁性物中TFe含量(磁铁精矿品位)大于66％,比B矿区样品的磁性物中TFe含量(小于57％)高,A矿区的磁铁矿选矿效果明显好于B矿区,说明对磁性物中TFe含量的测定能够更好地反映矿石的可选性.原矿样品中P、S的含量分别为0.328％、0.271％,而样品的磁性物中P、S的含量为0.021％、＜0.005％,均达到铁矿石冶炼标准;原矿样品中V2O5、TiO2的含量分别为0.156％、1.37％,而样品的磁性物中V2O5、TiO2含量分别为0.823％、13.62％,达到了铁矿石冶炼标准.原矿样品的(CaO+MgO)/(SiO2 +Al2O3)值为0.876,为自熔性矿石,而其磁性物的(CaO+ MgO)/(SiO2+Al2O3)值为0.453,为酸性矿石.由此说明,单纯测定原矿样品中的各成分尚不能对磁铁矿的可选性进行科学性评价,只有进一步测定磁铁矿的磁性物中各成分的含量,才能够对磁铁矿进行可靠的评价.本文通过对磁铁矿中磁性物成分的测定,为磁铁矿的选冶性能提供了新的评价方法.     

X射线荧光光谱法测定含金石英石中7种成分

采用粉末直接压片,波长色散多道荧光光谱法快速测定含金石英石样品中SiO2、Al2O3、TFe2O3、CaO、MgO、Pb、Zn等7种成分。根据含金石英石中SiO2的含量范围,选取了与试样基体相匹配的含金石英生产样作为校准样品,采用化学法准确定值,确定了仪器的最佳分析参数。对于Si和Al轻元素,荧光强度随粒度变化较为显著;制作的校准样品应密封保存,粉末压片后需马上进行测试。方法操作简单,成本低,测定范围宽,灵敏度高,精密度(RSD,n=11)均小于2.5%。与化学法对照,结果符合较好。     

大别山区石英质玉宝石矿物学特征研究

大别山区石英质玉属新近发现的一种石英质玉（简称＂大别山玉＂）,具色彩绚丽、质地细腻温润等特点。利用偏光显微镜、扫描电子显微镜、X射线粉末衍射、化学分析、红外光谱分析等方法,重点对＂大别山玉＂的矿物组成、化学成分、物理光学性质、微结构、红外吸收光谱等特征进行研究。结果表明,＂大别山玉＂具较典型的微粒-细粒结构,主要矿物为石英,含少量的绢云母、绿泥石、萤石、黄铁矿及其它粘土矿物等次要矿物,实属石英质玉;其化学成分相对较纯,主成分为SiO2,含少量的Al2O3,CaO,MgO,Fe2O3,FeO,K2O等;其红外反射光谱以Si—O非对称伸缩振动致特征的1177,1104 cm-1谱带、Si—O—Si对称伸缩振动致800,781cm-1分裂谱带以及由Si—O弯曲振动致492 cm-1较强谱带和542 cm-1弱谱带为特征。同时,还对＂大别山玉＂的结晶度及水的赋存状态一并给予了探讨。     

The terrestrial fauna of the Late Triassic Pant-y-ffynnon Quarry fissures,South Wales,UK and a new species of Clevosaurus (Lepidosauria: Rhynchocephalia)

Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.     

Définition d'une limite multicritère ; stratigraphie du passage Campanien–Maastrichtien du site géologique de Tercis (Landes,SW France)Definition of a multi-criteria boundary; stratigraphy of the Campanian–Maastrichtian interval of the geological site at Tercis (Landes,SW France)

Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.     

The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts

The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H₂O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H₂O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.     

Quaternary stresses revealed by calcite twinning inversion: insights from observations in the Savonnières underground quarry (eastern France)

Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ₁ roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).     

NONMETALS DEPOSITS

正20141520 Bo Ying(Key Laboratory of Metallogeny and Mineral Assessment,MLR,Beijing 100037,China);Liu Chenglin Saline Spring Hydrochemical Characteristics and Indicators for Potassium Exploration in Southwestern and Northern Tarim Basin,Xinjiang(Acta Geoscientica Sinica,ISSN1006-3021,CN11-3474/P,34(5),2013,p.594-602,5 illus.,3 tables,28 refs.)     

MATHEMATICAL GEOLOGY

正20141243Chen Ge(Hangzhou Research Institute of Petroleum Geology,PetroChina,Hangzhou 310023,China);Si Chunsong Study on Sedimentary Numerical Simulation Method of Fan Delta Sand Body(Journal of Geology,     

PROSPECTING EXPLORATION

正20142599Chen Sanming(Guangxi Key Laboratory of Concealed Deposits Exploration,Guilin University of Technology,Guilin541004,China);He Yuzhou Block Model and Reserves Estimation of Panzhihua Iron Deposit Based on 3D Geological Modeling(Journal of Guilin University of Technology,ISSN1674-9057,CN45-1375/N,33(4),2013,p.610-615,9illus.,1table,15refs.)     

STRUCTURAL GEOLOGY

正20140594 Bai Daoyuan(Hunan Institute of Geology Survey,Changsha 410016,China);Zhong Xiang Faults in the Jingzhou Basin and Their Tectonic Settings(Geotectonica et Metallogenia,ISSN1001-1552,CN44-1595/P,37(2),2013,p.173-183,6illus.,59refs.)Key words:basin evolution,tectonic setting,South China In the Upper Paleozoic and Jurassic se-     

STRUCTURAL GEOLOGY

正20141912Cao Hui(State Key Laboratory for Continental Tectonics and Dynamics,Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China)Gravitational Collapse and Folding during Orogenesis:A Comparative Study of FIA Trends and Fold Axial Plane Traces(Geology in China,ISSN1000-3657,CN11-1167/P,40(6),2013,p.1818-1828,9illus.,35refs.,with