华南陆相二叠—三叠系界线地层研究新进展

近3年通过对滇东黔西地区陆相二叠-三叠系界线地层的研究，获得了许多新的进展：1）证实滇东黔西地区是陆相二叠-三叠系界线研究的良好地区；2）发现并证明研究区有连续的陆相二叠-三叠系界线地层；3）发现陆相二叠-三叠系界线附近存在事件成因的“界线粘土岩”；4）丰富了研究区二叠-三叠系界线附近的古生物资料；5）分析研究了宣威组露头地层层序；6）进行了华南海相和陆相二叠-三叠系地层界线之间的对比。     

论两种二叠-三叠系界线

<正> 近年来许多地质学家围绕着二叠-三叠系界线的划分问题做了大量的工作,关于二叠-三叠系之间界线定义,尚未取得一致意见。目前议论较多的主要是两条界线:1.Otoceras层之底——传统界线     

中国天山地区二叠—三叠系界线磁性特征的初步研究

天山地区二叠─三叠系地层发育齐全、沉积连续、化石丰富、出露良好，是研究和建立非海相二叠─三叠系界线层型剖面的理想地区之一。通过对吉木萨尔县三台大龙口背斜北翼、南翼剖面及乌鲁木齐县芦草沟二叠─三叠系界线剖面古地磁特征研究，提供了二叠─三叠系界线划分的古地磁依据。国内二叠─三叠系海、相非海相剖面研究表明，在海相或非海相二叠─三叠系界线附近均有频繁极性倒转，即伊拉瓦次（Illawarra）极性间隔的存在，为全球性二叠─三叠系界线划分与对比奠定了基础。     

华南二叠—三叠系界线处的磁化率特征及其对比意义

目前界线层型的确定多以生物标定,但在国际地层委员会二叠－三叠系界线工作组确定的４个二叠－三叠系界线层型候选剖面中,生物地层界线却较难精确对比。因此,其他具有广泛对比意义的事件地层标志也被用来作为确定二叠－三叠系界线的辅助标志。本文把磁化率特征（古气候的代用指标）运用二叠－三叠系界线地层研究中,发现华南许多剖面上高精度的磁化率在二叠－三叠系界线处具有同步的变化趋势,因而,磁化率特征可以作为二叠－三叠     

湘西北地区二叠-三叠系界线地层与牙形石分带

本文主要从生物地层学角度探讨湘西北地区二叠-三叠系界线划分。笔者对该区上二叠世地层进行了重新划分;以牙形石地层分布、百分比丰度和演化关系为基础,将该区二叠系栖霞阶顶部至三叠系格里斯巴赫阶划分为13个牙形石带,并与区内其它门类化石带和国内外同期牙形石带做了详细对比;界线层夹有多层海底火山喷发物成因的伊利石-蒙脱石粘土岩,界线上见有“过渡层”或生物“混生层”,证明该区界线地层为连续沉积。据界线上下“二叠型”与“三叠型”生物的盛衰和演替,以菊石Hypophiceras带或“过渡层”的底部为该区二叠-三叠系界线。     

二叠系-三叠系界线的事件地层学标志

<正> 传统的二叠-三叠系界线,是以喜马拉雅山的Otoceras层的底作为三叠系底界(Die-ner 1912)。70年代以来,国际上提出了多种方案(Waterhouse 1973,1976;Kozur 1977;Newell 1978),我国80年代出现了分歧意见(李子舜、姚建新1984;李子舜、詹立培等1986)。1986年在意大利举行的“西特提斯南阿尔卑斯的二叠系及二叠-三叠系界线国际     

浙江长兴煤山二叠—三叠系界线年龄测定

本文报道了用高灵敏度高分辨率离子探针,测定的浙江长兴煤山二叠—三叠系临界层位,斑脱岩中锆石的U-Pb年龄,结果为351.3±3.4Ma(2σ)。这是国际上首次直接从界线层位准确测定的二叠—三叠系界线的同位素年龄。长兴煤山二叠—三叠系界线剖面是迄今所发现的地层剖面连续,所含化石门类众多,数量丰富,且在临界层位夹有火山岩层的少有剖面之一,它不仅对国际显生宙地质年表的研究具有重要意义,而且也具有作为二叠—三叠系界线层型剖面的优越条件。     

扬子台区二叠-三叠系界线层综合地层学研究

华南二叠－三叠系界线研究一直在地学界备受瞩目．目前被广泛接受的界线标准化石为牙形石Ｈｉｎｄｅｏｄｕｓｐａｒｖｕｓ,该化石的首现位置被定义为二叠－三叠系界线层型剖面点．然而在全球研究精度最高的４个候选层型剖面中,生物地层单位的对比问题尚存在分歧,从而影响了区域高精度地层对比框架的建立．在扬子台区丰富的资料及大量二叠－三叠系界线剖面进一步研究的基础上,发现许多剖面上二叠－三叠系界线处具有相似的岩石地层特征．其基本结构为粘土岩层、灰岩或泥灰岩层及粘土岩层沉积组合．从综合地层学角度的研究表明：该套沉积组合（界线层）在岩性特征、生物群总体面貌以及其他事件标志（如同位素年龄、磁性地层、地球化学特征等）上具有一定的对比意义．认为界线层应该是等时的地层单位,是扬子台区二叠－三叠系界线处重要的标志层组,并对这套地层进行了区域性对比．这套地层的发现大大提高了扬子台区二叠－三叠系界线处地层的对比精度．     

华南二叠－三叠系的事件地层与生物地层界线

华南二叠－三叠系界线研究应严格区分事件地层界线与生物地层界线。“界线粘土”层的底界即为事件地层界线。生物地层界线定义不能与“混生层”或“过渡层”的概念连在一起。长兴煤山忠心大队剖面是最好的二叠－三叠系全球界线层型剖面点（ＧＳＳＰ）。二叠－三叠系生物地层界线定义为ＨｉｎｄｅｏｄｕｓｐａｒｖｕｓＭｏｒｐｈｏｔｙｐｅ１的首次出现,其位置就在长兴剖面界线层（混生层）２的内部,比事件地层界线高１５ｃｍ。ＨｉｎｄｅｏｄｕｓｐａｒｖｕｓＭｏｒｐｈｏｔｙｐｅ１的首次出现,即为长兴阶的顶界。     

华南二叠－三叠系的事件地层与生物地层界线

华南二叠－三叠系界线研究应严格区分事件地层界线与生物地层界线。“界线粘土”层的底界即为事件地层界线。生物地层界线定义不能与“混生层”或“过渡层”的概念连在一起。长兴煤山忠心大队剖面是最好的二叠－三叠系全球界线层型剖面点（ＧＳＳＰ）。二叠－三叠系生物地层界线定义为ＨｉｎｄｅｏｄｕｓｐａｒｖｕｓＭｏｒｐｈｏｔｙｐｅ１的首次出现,其位置就在长兴剖面界线层（混生层）２的内部,比事件地层界线高１５ｃｍ。ＨｉｎｄｅｏｄｕｓｐａｒｖｕｓＭｏｒｐｈｏｔｙｐｅ１的首次出现,即为长兴阶的顶界。     

Wavelength-dispersive X-ray fluorescence spectrometric determination of Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in komatiites

Komatiites are mantle-derived ultramafic volcanic rocks. Komatiites have been discovered in several States of India, notably in Karnataka. Studies on the distribution of trace-elements in the komatiites of India are very few. This paper proposes a simple, accurate, precise, rapid, and non-destructive wavelength-dispersive x-ray fluorescence (WDXRF) spectrometric technique for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in komatiites, and discusses the accuracy, precision, limits of detection, x-ray spectral-line interferences, inter-element effects, speed, advantages, and limitations of the technique. The accuracy of the technique is excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Zr, Nb, Ba, Pb, and Th and very good (within 4%) for Y. The precision is also excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th. The limits of detection are: 1 ppm for Sc and V; 2 ppm for Cr, Co, and Ni; 3 ppm for Cu, Zn, Rb, and Sr; 4 ppm for Y and Zr; 6 ppm for Nb; 10 ppm for Ba; 13 ppm for Pb; and 14 ppm for Th. The time taken for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in a batch of 24 samples of komatiites, for a replication of four analyses per sample, by one operator, using a manual WDXRF spectrometer, is only 60 hours.     

高压微波消解法测定醋酸纤维过滤器采集的微尘粒子中的砷镉钴铬铜铁锰镍铅钒锌

最新的流行病学研究表明,空气中较高浓度的悬浮细颗粒可能对人类的健康有不利的影响。根据该项研究显示,由于心脏病、慢性呼吸问题和肺功能指标恶化而导致死亡率的升高与细尘粒子有关。这些研究结果已经促使欧盟于1999年4月出台了限制空气中二氧化硫、二氧化氮、氧化氮、铅和颗粒物含量的法案(1999/30/EC),对各项指标包括对可吸入PM10颗粒的浓度提出了新的限制性指标。PM10颗粒是指可以通过预分级器分离采集的气体动力学直径小于10μm的细颗粒。目前研究的兴趣重点逐步偏向PM2.5这些更细微颗粒物,PM2.5这种颗粒物对健康有明显的不利影响。在欧盟指令2008/50/EC中,对PM10和PM2.5都提     

Isotopic systematics of He,Ar, S,Cu, Ni,Re, Os,Pb, U,Sm, Nd,Rb, Sr,Lu, and Hf in the rocks and ores of the Norilsk deposits

This paper reports the first results of a study of 11 isotope systems (³He/⁴He, ⁴⁰Ar/³⁶Ar, ³⁴S/³²S, ⁶⁵Cu/⁶³Cu, ⁶²Ni/⁶⁰Ni, ⁸⁷Sr/⁸⁶Sr, ¹⁴³Nd/¹⁴⁴Nd, ^206–208Pb/²⁰⁴Pb, Hf–Nd, U–Pb, and Re–Os) in the rocks and ores of the Cu–Ni–PGE deposits of the Norilsk ore district. Almost all the results were obtained at the Center of Isotopic Research of the Karpinskii All-Russia Research Institute of Geology. The use of a number of independent genetic isotopic signatures and comprehensive isotopic knowledge provided a methodic basis for the interpretation of approximately 5000 isotopic analyses of various elements. The presence of materials from two sources, crust and mantle, was detected in the composition of the rocks and ores. The contribution of the crustal source is especially significant in the paleofluids (gas–liquid microinclusions) of the ore-forming medium. Crustal solutions were probably a transport medium during ore formation. Air argon is dominant in the ores, which indicates a connection between the paleofluids and the atmosphere. This suggests intense groundwater circulation during the crystallization of ore minerals. The age of the rocks and ores of the Norilsk deposits was determined. The stage of orebody formation is restricted to a narrow age interval of 250 ± 10 Ma. An isotopic criterion was proposed for the ore-bearing potential of mafic intrusions in the Norilsk–Taimyr region. It includes several interrelated isotopic ratios of various elements: He, Ar, S, and others.     

硅酸盐中铁、锰、钛、钙、钾、磷、硅、铝、镁、钠、锶、铷、钡的X-射线荧光光谱定量测定

本文介绍样品经四硼酸锂熔融制成玻璃小饼。采用Lachance模式和理论a系数来校正元素间的效应,由3080E型X-射线荧光谱仪和DF-350B数据处理系统完成硅酸盐中十三个项目的测定。     

硅酸盐类样品中硅、铁、铝、钛、锰、钙、镁、钾、钠和磷的x射线荧光光谱测定

本文拟定了一种以熔融法制备样片,用X射线荧光光谱测定硅酸盐类样品中Si、Fe、Al、Tj、Mn、Ca、Mg、K、Na、P等元素的分析方法。在对不同靶材X光管和分光晶体实验对比的基础上,选择了最佳的测量条件。该法具有快速、准确,测量范围广,检测限低,价格便宜等优点。经过近百个各种类型标样或管理样品的分析对比表明,本法不仅适用于硅酸盐类岩石样品的分析,还适用于铁矿、铝土矿、碳酸盐类岩矿样品以及水泥、耐火材料等样品的分析。     

Viscous, cohesive, non-Newtonian, depositing, radial slurry flow

Mining induced subsidence can significantly affect mining costs where major surface facilities and natural environment need to be protected. Overburden grout injection is a technology used to control coal mine subsidence by injecting the mine waste material extracted from the coal back into the inter-burden rock during longwall mining. The flowing slurry is here categorised as a nonlinear viscous cohesive (Bingham plastic) fluid. During longwall mining the grout slurry is pumped into the separated beds of the rock mass through a central vertical borehole, which is drilled deep into the inter-burden rock strata above the coal seam. However, a blockage can occur in the injection system when the slurry velocity falls below a certain critical threshold velocity, indicating a material phase change from cohesive-viscous to cohesive-frictional. In situ field injection tests through boreholes have been simulated at a smaller scale at the CSIRO laboratory in Brisbane by pumping the slurry through a radial disk (gap = 4 mm) from its centre. Laboratory experiments indicate a general, nonlinear, cohesive, viscous, frictional model for shear behaviour of the slurry, in which the material shear parameters are functions of the disk radial distance. Complete dimensional and dimensionless analytical solutions have been developed based on an approach related to Bingham–Herschel–Bulkley fluid mechanics. The derived formulae include relations for minimum pump pressure, local pressure and pressure gradient, wall shear stress, volume rate, velocity and velocity gradient. The theoretical results match the experimental measurements. The experiments covered slurries with maximum particle sizes of 0.5 to 2 mm with about 50% being larger than 100 µm. The viscosities at the various solids concentrations were measured with a standard torsion viscometer. This study differs from the previous research in several distinct aspects, namely, consideration of the variable shear parameters rather than fixed values, inclusion of total nonlinear behaviour, and implementation of a friction function to mimic behaviour of the deposited and consolidating stiff slurry, which can cause a significant pressure rise as a result of the increased shear resistance.     

Mountains,nations, parks,and conservation

Between 1985 and 1991, two new mountain protected areas (MTNPA) covering more than 35,000 km² and based on participatory management models — the Makalu-Barun National Park and Conservation Area, Nepal, and Qomolangma Nature Preserve, Tibet Autonomous Region — were successfully established through the collaborative efforts of Woodlands Mountain Institute and conservationists in China and Nepal. Characteristics common to both projects include the importance of establishing (1) effective rationales, (2) local support constituencies, (3) a senior advisory group, (4) a task force, (5) linkages between conservation and development, and (6) fund raising mechanisms. The lessons derived from the experiences of Woodlands Mountain Institute are of significant value to others in preserving MTNPA. Increased collaboration and communication between all interested in conservation, however, will remain a critical component for expanding mountain protected area coverage to throughout the world.     

Regional distribution of Al,B, Ba,Ca, K,La, Mg,Mn, Na,P, Rb,Si, Sr,Th, U and Y in terrestrial moss within a 188,000 km2 area of the central Barents region: influence of geology,seaspray and human activity

Five hundred and ninety-eight samples of terrestrial moss (Hylocomium splendens and Pleurozium schreberi) collected from a 188,000 km² area of the central Barents region (NE Norway, N Finland, NW Russia) were analysed by ICP-AES and ICP-MS. Analytical results for Al, B, Ba, Ca, K, La, Mg, Mn, Na, P, Rb, Si, Sr, Th, U and Y concentrations are reported here. Graphical methods of data analysis, such as geochemical maps, cumulative frequency diagrams, boxplots and scatterplots, are used to interpret the origin of the patterns for these elements. None of the elements reported here are emitted in significant amounts from the smelting industry on the Kola Peninsula. Despite the conventional view that moss chemistry reflects atmospheric element input, the nature of the underlying mineral substrate (regolith or bedrock) is found to have a considerable influence on moss composition for several elements. This influence of the chemistry of the mineral substrate can take place in a variety of ways. (1) It can be completely natural, reflecting the ability of higher plants to take up elements from deep soil horizons and shed them with litterfall onto the surface. (2) It can result from naturally increased soil dust input where vegetation is scarce due to harsh climatic conditions for instance. Alternatively, substrate influence can be enhanced by human activity, such as open-cast mining, creation of ‘technogenic deserts’, or handling, transport and storage of ore and ore products, all of which magnify the natural elemental flux from bedrock to ground vegetation. Seaspray is another natural process affecting moss composition in the area (Mg, Na), and this is most visible in the Norwegian part of the study area. Presence or absence of some plant species, e.g., lichens, seems to influence moss chemistry. This is shown by the low concentrations of B or K in moss on the Finnish and Norwegian side of the (fenced) border with Russia, contrasting with high concentrations on the other side (intensive reindeer husbandry west of the border has selectively depleted the lichen population).     

NEW SET OF LOW CONCENTRATION STANDARDS FOR LA, CE, SM, YB, LU, Y, SC, V, NB AND TA IN SILICATES

We have developed a set of four synthetic standards for the rare earth and high field strength elements designed for use in the determination of those elements in silicates. The base material is a glass nominally at the eutectic of the MgO-Al₂O₃-SiO₂ ternary system. The nominal doping level was 2 wt% of the elements as oxides. To avoid problems associated with peak interference, the elements were doped in four separate glasses.