西藏那曲地区孔玛盆地第四纪昆虫化石的发现及意义

首次在西藏那曲地区孔玛盆地第四系湖相沉积地层中发现了昆虫化石,对昆虫化石的特征和产出层位进行了描述,昆虫化石经初步鉴定分别属于膜翅目、双翅目和异翅目.采集了该套地层的ESR年代学样品,测试结果表明该套地层的时代为早中更新世.昆虫的分布演化与环境关系密切.这一发现为研究青藏高原第四纪以来的生物进化,湖泊、河流演化,气候变化,古地理、古环境变迁.第四系地层划分等提供了新资料.     

西藏阿里札达盆地上新统鼠兔类牙齿化石的发现

首次在西藏阿里札达盆地上新世河湖相沉积地层中发现了鼠兔类牙齿化石，对鼠兔类牙齿化石的基本特征进行了描述，并在同一层位中采集了大量孢粉、古动物和古植物化石。结合区域地质特征，产出鼠兔类牙齿化石地层的古地磁、ESR测年资料，沉积学特征等的简要分析，认为札达盆地鼠兔类的演化迁徙与上新世时气候由温暖湿润向寒冷潮湿-温和干旱的变化有关。显然，这一发现有助于认识青藏高原新近纪上新世的生物演化、气候变化和构造活动，并为研究青藏高原新近纪以来的生物进化、湖泊与河流演化、气候变化、古地理与古环境变迁和古近系、新近系、第四系地层划分等提供了新资料。     

河北丰宁中生代晚期昆虫群落与生态地层的初步研究

在对河北丰宁森吉图地区一条中生代晚期地质剖面进行生态地层研究的基础上,建立了６个昆虫化石群落,恢复了它们所代表的环境,并对相应的生态地层剖描述,作出了生态地层柱状图、该生态地层剖面由２个昆虫群落带、２个间隔带和１个昆虫化石组合层构成。生态地层划分的结果显示了中生代晚期在冀北许多地区具有代表性的盆地学演变的一般模式,古地理分析表明森吉图地区在古生代晚期温暖的气候条件下共经历了４个演化阶段。     

辽西义县组襀翅目昆虫化石及其古生态分析

本文综述了襀翅目昆虫的历史发展及辽西义县组地层中发现的襀翅目化石种类。襀翅目现生昆虫生境范围狭窄,不同类群反映不同的水生环境,将今论古,已发现的襀翅目化石类群反映了高山、河流、山间溪流以及低地湖泊等古环境的存在。襀翅目化石类群反映的这些古环境与地层学分析的沉积环境,以及地层中其他动植物化石反映的古环境相符。     

西藏恐弄拉地区中侏罗统桑卡拉佣组的厘定及其地质意义

贵州省地质调查院在开展西藏自治区1∶5万班戈县恐弄拉地区区域地质调查时,在马前乡恐弄拉西侧车尖西南一带前人划分的一套早白垩世桂牙岩组碳酸盐岩地层中采集了腕足类和腹足类化石,据采集的古生物化石时代确定此套碳酸盐岩地层为中侏罗世沉积(晚巴柔期—卡洛期),通过岩石组合特征、基本层序、沉积环境及生物化石时代对比,将该套地层重新厘定为桑卡拉佣组。这一地层的确定为冈底斯带地层区侏罗系地层划分对比、地层格架建立提供了重要的依据,并为中生代盆地的演化历史,古地理轮廓的确定提供了新的基础资料。     

东昆仑造山带纳赤台岩群基质地层发现中新世孢粉组合

东昆仑造山带纳赤台岩群是一套混杂堆积地层，有外来岩块和基质地层之分别，以往根据岩块中的化石将该套地层划为下古生代的奥陶系—志留系。根据笔者等的研究和野外调查，2006年首次报道了在菜园子沟剖面该岩群基质地层中发现古近纪中—晚渐新世的孢粉44属31种。本文报道的是在水泥厂剖面该岩群基质地层中发现的新近纪中—晚中新世的孢粉化石44属33种。新近纪孢粉化石的发现对进一步厘定该岩群的地质时代、分析其古环境及东昆仑造山带的形成演化等方面具有重要的地质意义。     

西藏申扎县木纠错地区晚三叠世多布日组的发现及其地质意义

吉林地质调查院在开展西藏自治区1：25万多巴区幅区域地质调查时，在木纠错西的申扎县多布日一带发现一套陆相－海陆交互相－滨浅海相地层，并采集到了珊瑚化石、海参化石、植物化石、介形类化石、腹足化石、藻类化石和孢粉化石等。根据这些古生物化石确定该套地层为晚三叠世沉积。从而首次证明了冈底斯－腾冲区永珠蛇绿岩带以南存在晚三叠世地层。这一发现为我国三叠系的划分对比提供了重要的依据，并为古特提斯海的演化历史，古地理轮廓的确定以及青藏高原的形成演变历史提供了新的资料。     

东昆仑纳赤台岩群混杂堆积的古生物学证据及其地质意义

纳赤台岩群是东昆仑造山带一套构造—沉积混杂堆积地层,由各时期外来岩块和基质系统两大部分组成。以往曾依该岩群岩块中的珊瑚、腕足类、腹足类化石等划分为晚奥陶世或古生代。本文首次报道该岩群基质地层中发现的44属31种古近纪中—晚渐新世孢粉化石。这些化石的发现为厘定该岩群的地质时代、进一步确定该岩群为构造—沉积混杂堆积以及阐述东昆仑造山带形成演化机制等方面提供了有力证据,具有重要地质意义,而且在探讨古近纪生物地理区系和古环境等方面提供了重要参考资料。     

东昆仑纳赤台岩群混杂堆积的古生物学证据及其地质意义

纳赤台岩群是东昆仑造山带一套构造-沉积混杂堆积地层,由各时期外来岩块和基质系统两大部分组成。以往曾依该岩群岩块中的珊瑚、腕足类、腹足类化石等划分为晚奥陶世或古生代。本文首次报道该岩群基质地层中发现的44属31种古近纪中-晚渐新世孢粉化石。这些化石的发现为厘定该岩群的地质时代、进一步确定该岩群为构造-沉积混杂堆积以及阐述东昆仑造山带形成演化机制等方面提供了有力证据,具有重要地质意义,而且在探讨古近纪生物地理区系和古环境等方面提供了重要参考资料。东昆仑纳赤台岩群混杂堆积的古生物学证据及其地质意义@郭宪璞$中国地…     

东昆仑万宝沟岩群基质地层中发现白垩纪孢粉组合

东昆仑造山带万宝沟岩群是一套混杂堆积地层,有外来岩块和基质地层之分,以往根据岩块中的化石将该套地层的时代划为前寒武纪的蓟县纪—青白口纪。根据野外调查和研究结果,曾于2005年首次报道了在昆仑桥南剖面该岩群基质地层中发现古近纪晚始新世至中—早渐新世的孢粉50属12种;同年还报道了在该岩群命名地点万宝沟剖面发现古近纪渐新世的孢粉22属15种。本次报道的是在昆仑桥北剖面该岩群基质地层中发现的早白垩世晚期—晚白垩世早期的孢粉化石43属19种(比较种)。白垩纪和古近纪孢粉化石的发现对进一步厘定该岩群的地质时代、分析其古环境及东昆仑造山带的形成演化具有重要意义。     

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     

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。     

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.     

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.     

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。     

Bellechester,Minnesota, USA,lagoon collapses

Bellechester, Minnesota, is a small community of approximately 155 residents located on the county line between Goodhue and Wabasha counties in southeast Minnesota's karst region. Bellechester is served by a 21-year-old wastewater treatment facility (WWTF) consisting of three waste-stabilization ponds. On 28 April 1992 six sinkholes were discovered to have drained cell 2 of the WWTF resulting in the loss of approximately 8.7×10⁶ 1 of partially treated effluent and about 600 m³ of soil into previously undetected subsurface voids of unknown dimensions. In the week following the collapse, approximately 200 water wells located within a 5-km radius of the WWTF were sampled in an after-the-fact, emergency sampling program. Twelve samples with elevated fecal coliform levels, 18 samples with nitrate-nitrogen greater than the 10 mg/1 standard, and no samples with elevated chlorides were found. However, the elevated levels could not be unambiguously attributed to the WWTF collapse. This is the third WWTF to fail by sinkhole collapse in southeast Minnesota since 1974. All three collapsed lagoons have been located in similar geomorphic and stratigraphic settings. However, at least two lagoons have collapsed in the adjacent area in northeast Iowa, and these lagoons are located at different stratigraphic positions. Twenty-two WWTFs constructed in southeast Minnesota's karst region in the last 25 years have been identified as subject to potential sinkhole collapse. An unknown but significant number of manure storage lagoons, flood control structures, etc., have also been constructed in the karst region and are at risk. Public agencies are beginning to develop plans to deal with the risk associated with existing and future waste lagoons in this environment. The critical hydrogeologic parameters that can be used to prioritize the risk of collapse at existing facilities include: (1) the lithology of the first bedrock beneath each lagoon, (2) the thickness of surficial materials between the lagoon and the bedrock surface, (3) the presence and construction of liners (seepage rate), and (4) the proximity to existing sinkholes.     

Mercury,arsenic, antimony,and selenium contents of sediment from the Kuskokwim River,Bethel, Alaska,USA

The Kuskokwim River at Bethel, Alaska, drains a major mercury-antimony metallogenic province in its upper reaches and tributaries. Bethel (population 4000) is situated on the Kuskokwim floodplain and also draws its water supply from wells located in river-deposited sediment. A boring through overbank and floodplain sediment has provided material to establish a baseline datum for sediment-hosted heavy metals. Mercury (total), arsenic, antimony, and selenium contents were determined; aluminum was also determined and used as normalizing factor. The contents of the heavy metals were relatively constant with depth and do not reflect any potential enrichment from upstream contaminant sources.     

滇东南花岗岩与锡、银、铜、铅、锌多金属矿床的成因关系

滇东南锡、银、铅、锌多金属矿床主要分布在个旧、白牛厂、都龙3个矿区,而滇东南较大的3个花岗岩体又分别出露在3个矿区或附近.花岗岩体均形成于燕山晚期,岩石化学、矿物成分相似,富含锡、银、铅、锌、钨、铜等成矿元素.矿床主金属元素组合与岩体之间的距离由远而近出现由锡、钨、(铍、铌、钽)→锡、钨、(铁)、铜、铟→锡、铅、锌、银、铟、(锑)有规律的变化.花岗岩浆是成矿物质来源和成矿热源.岩浆侵入初期使上覆地层隆起产生背斜(凹陷部位成向斜);同时使地层产生一系列裂隙、压性断层或层间断裂;岩浆侵入晚期,这些断层再次活动,表现为张性,岩浆产生的含矿热液沿由其活动所造成的断裂迁移、充填、交代、沉淀而形成矿床.     

岩石密度和超高压岩石折返速率

在常温常压条件下对中国大陆科学钻CCSD主孔100-3000米岩心样品进行了密度测量,建立了密度连续剖面,并界定了不同超高压岩石的密度值。通过对比高温高压物性实验资料,岩石密度随着退变程度增强而降低,榴辉岩密度变化序列为3.52g/cm3→3.49g/cm3→3.07g/cm3→2.93g/cm3。超高压长英质岩石密度变化序列为3.00g/cm→2.80g/cm3→2.65g/cm3。上述实验资料是讨论不同折返阶段岩石所受浮力的基础,为研究折返速率大小提供了基本参数。本文通过折返板块运动平衡时,上浮力与粘滞力平衡这一关系式,定量研究了大陆俯冲板块的折返速率,认为密度差产生上浮力从而引起折返,温度对板块折返速率的影响最为显著;密度差大小、折返角度、折返板块大小对折返速率也有直接的影响。定量模拟分析表明,在温度高于850℃时,板块的折返速率可以超过100mm/a;当温度降至700℃时,折返速率则低于1.5mm/a。作者认为在折返早期,温度较高,板块快速折返至60-70km榴辉岩相深度;随着传导散热,温度降低,板块以较慢的速率折返至中下地壳。折返速率的估算表明,浮力是板块折返第一阶段(从>100km深部折返至<40km的中下地壳)的主要驱动力。