内蒙古阿荣旗太古山早白垩世光华组一段沉积岩层序地层特征

阿荣旗太古山西北部陆相盆地光华组一段沉积岩非常发育,为一套正常火山碎屑沉积岩组合.根据岩石组合特征、组构、岩层垂向变化规律、沉积环境变化等分析,本区光华组一段沉积岩自下而上可划分为1个Ⅱ级层序,2个Ⅲ级层序及7个Ⅳ级层序.对其进行层序地层学等方面的研究,为大兴安岭地区中生代陆相盆地层序地层的研究提供参考.     

冈底斯带扎雪石英二长斑岩体的地质特征及构造环境

扎雪石英二长斑岩体分布于冈底斯岩浆弧带的中段，侵入于前奥陶系松多岩群和石炭-二叠系来姑组中，并被帕那组火山岩呈火山沉积不整合覆盖，其黑云母K-Ar年龄值为54．42Ma，时代为始新世。岩石学和岩石化学特征：ω(SiO2)=67．04％～69．75％、ω(Al2O3)=14.85％～16．75％、ω(TiO2)=0.45％～0．53％、ω(K2O Na2O)=9．64％～10.28％、ω(K2O/Na2O)=1．8～1．97，表明扎雪石英二长斑岩体为酸性钾玄质浅成侵入岩。它与冈底斯带上广泛发育的林子宗群年波组火山同时异相，形成于印度板块和欧亚板块后碰撞阶段，成为大洋俯冲体制向大陆碰撞体制转换的岩石记录。     

冀北晚侏罗世张家口组内段的划分

冀北晚侏罗世张家口组内岩石地层单位长期以来一直没有一个较统一的划分方案，使之划分较为混乱，影响了其合理地层层序的建立及区域地层对比。笔者通过“冀北中生代陆相火山一沉积盆地1：25万填图方法研究”项目的工作，提出张家口组内以相序的岩石组合为基本单元将其依次划分3个岩性段。一段主要为弱喷发相序的岩石组合；二段主要为爆发相序的岩石组合；三段主要为喷发沉积相序的岩石组合。三者分别代表该组某破火山的初始爆发阶段、大规模爆发阶段和破火口塌陷沉积阶段。由此划分的岩性段可以较好地反映火山构造特征，建立合理的地层层序，有助于火山演化历史的研究。使岩石地层单位划分与火山-沉积盆地研究有机地结合在一起。     

冀北晚侏罗世张家口组段的划分

4冀北晚侏罗世张家口组的岩石地层单位长期以来一直没有一个较统一的划分方案,划分较为混乱,影响了其合理的地层层序的建立及区域地层对比。根据《冀北中生代陆相火山-沉积盆地1∶25万填图方法研究》项目的工作成果,提出张家口组以相序的岩石组合为基本单元将其依次划分为3个岩性段的方案。一段主要为弱喷发相序的岩石组合;二段主要为爆发相序的岩石组合;三段主要为喷发沉积相序的岩石组合。三者分别代表该组某破火山的初始爆发阶段、大规模爆发阶段和破火口塌陷沉积阶段。由此划分的岩性段可以较好地反映火山构造特征,建立合理的地层层序,有助于火山演化历史的研究,使岩石地层单位的划分与火山-沉积盆地的研究有机地结合在一起。     

青海省巴龙贡噶尔组的重新划分及地质意义

南祁连阳康地区分布着一套变形较强的区域低温动力变质岩系,前人将其划归为巴龙贡噶尔组。通过对该套地层进行岩石地球化学、锆石LA-ICP-MS U-Pb年代学研究,发现其与巴龙贡噶尔组的原始含义不同,对该地层中不同的岩石组合重新进行了划定,其主要由两部分组成:其中的变质砂岩、变质粉砂岩和板岩等变质变形较弱,与巴龙贡噶尔组的原始含义相吻合,时代为志留纪;而其中的片岩类岩石,变质变形较强,恢复原岩为火山岩和火山碎屑岩,SiO_2含量为57.1%～68.74%,Al_2O_313.04～14.98%,Al_2O_3(K_2O+Na_2O+CaO)(分子数)1,里特曼指数(σ)在1.4～4.42之间,大多在2±,主要为钙碱性系列。稀土总量∑REE=186.17×10~(-6)～203.79×10~(-6),稀土元素球粒陨石标准化模式曲线为向右倾斜的轻稀土富集型,铕略亏损,具负异常,亲石元素Ba和Sr富集,而Rb强烈亏损,Ba相对Rb和Th、Ti相对于Sm和Y呈明显负异常,反映出具有典型中基性-中酸性火山岩微量元素特征。在火山岩中获取锆石U-Pb测年结果表明其岩浆形成的时代为新元古代(819±2 Ma)(阳康片岩),为一套基性火山岩及火山碎屑岩建造,具有大陆裂谷盆地的特点,该片岩的发现填补了该区域未有新元古代历史记录的空白,反映了该地区与全球元古代Rodinia超大陆聚合事件的一致性。     

西准谢米斯台山马门特一带石炭系黑山头组的厘定——来自地质地球化学和年代学证据

西准噶尔谢米斯台山中段马门特周围及东部一带一套火山熔岩、火山碎屑岩地层,前人将其归为中泥盆统呼吉尔斯特组。作者在该地层玄武岩中测得LA-ICP-MS锆石年龄为(343±3.1)Ma(n=16,MSWD=0.68),为早石炭世。依据剖面及岩石组合与《新疆维吾尔自治区地层清理》(1999)及邻区下石炭统黑山头组岩性对比分析,将其厘定为下石炭统黑山头组。该组火山岩具有高铝、高碱特征,轻重稀土元素分馏明显,大离子亲石元素Ba,Pb,Sr相对富集,高场强元素Th,U,Nb相对亏损,具有板内碱性玄武岩性质,结合区域构造演化特征,认为该火山岩形成于弧后盆地环境。     

大兴安岭北段根河地区早白垩世火山杂岩特征及成因探讨

大兴安岭北段根河地区早白垩世火山杂岩按岩石及其地球化学特征，可划分为3类：第Ⅰ类为流纹质岩石，富Si、碱，低Al、Ti，Na2O／K2O〈1，具有明显的负Eu异常（δEu=0．27-0．59），富Rb，贫Sr、Ba；第Ⅱ类为粗面英安质岩石，富Al、Ti，Na2O／K2O〉1，具弱的负Eu异常（δEu=0．65-0．95），富Sr、Ba，贫Rb；研究认为第Ⅰ、Ⅱ类岩石产于挤压隆升相伴的拉张至造山后伸展构造环境。第Ⅲ类由安粗岩、歪长粗面岩组成，富Ti、Al，Na2O／K2O≥1．1，Eu无异常（δEu=0．93-1，06），Th／Ta、Ta／Hf值显示大陆板内伸展环境，其形成可能与玄武质岩浆的底侵作用有关。     

东天山卡拉塔格钠质火山岩岩石学、地球化学及成因

东天山卡拉塔格早泥盆世卡拉塔格组火山岩主要岩性为海相富钠质的安山岩、流纹岩和英安岩，夹少量的钠质玄武安山岩和钠质玄武岩以及正常系列的玄武安山岩。钠质火山岩的特征是：Na2O=1．69～6．38％，Na2O／K，O〉1，多在2～100间：无论是斑晶还是基质，斜长石均为富钠长石；酸性岩石斑晶主要是钠长石和石英，中基性岩石斑晶主要是钠长石（少量更长石）：酸性岩以斑状结构、霏细结构、球粒结构为主，而中基性岩以交织结构、玻晶交织结构为主。各类岩石全岩化学分析计算结果均含标准矿物Q、Hy、Hm，一部分含Di或C，在TAS图上全都投于亚碱性区；∑REE=25、96-96．11ppm，LaN／YbN=1．68-5．32，Eu／E^＊=0．46-1．25，LaN／SmN=1．01-2．95；强不相容元素适度富集，Nb和Ta强烈亏损，部分样品Cs、Rb、K、Zr和Hf适度亏损。这些特征表明，该区钠质火山岩的原始岩浆可能来自富钠俯冲洋壳熔体与地幔楔岩石反应的产物部分熔融。这样的岩浆形成机制与前人有关卡拉塔格是早泥盆世岛弧的认识相一致。     

内蒙古东南部西乌珠穆沁旗地区石炭纪-二叠纪岩石地层和层序地层

通过1:25万区域地质调查,对西乌珠穆沁旗-林西地区石炭纪-二叠纪地层进行了岩石地层学研究与重新归并划分,并进行了生物地层、层序地层及不整合面地层的多重地层划分与对比.研究了测区各地层的基本层序、沉积环境和沉积相,将石炭纪-二叠纪地层划分为3个沉积层序,建立了岩石地层和年代地层格架.石炭纪-早二叠世本巴图组(CPb)、格根敖包组(CPg)和阿木山组(CPa)三者为石炭纪-二叠纪西乌珠穆沁旗海槽同期异相地层的观点,能很好地解释这几套地层的相互关系.寿山沟组(P1ss)地层呈超覆不整合覆于以前地层或地质体之上;大石寨组(P2ds)为达到最大海泛面时海(水)下火山喷发的产物;哲斯组(P2z)是海盆地萎缩期的沉积产物.     

大杨树盆地中部甘河地区嫩江组沉积期古环境分析

正大杨树盆地位于内蒙古自治区东部阿荣旗、鄂伦春自治旗及黑龙江省甘南县境内,盆地西接大兴安岭,东依嫩江断裂与松辽盆地西缘紧邻,为在晚侏罗世褶皱基础上发育的一个呈北北东向长条带状展布的中新生代断陷—坳陷型盆地,面积约为15600 km~2,主要由火山岩、火山碎屑岩及正常碎屑岩组成,盆内地层自下而上为下白垩统龙江组、九峰山组、甘河组、上白垩统嫩江组以及新近系中新     

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.     

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。     

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.     

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。     

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。     

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.     

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.