R／S分析及矿井瓦斯涌出量的分形预测

介绍了分形理论中的时间序列（R／S）分析方法，讨论了赫斯特指数的理论意义和实际计算方法，并将其应用于矿井瓦斯涌出量预测。通过对矿井瓦斯涌出量时间序列的分形处理，根据极差、标准差的结构分维值的大小，对矿井瓦斯涌出量的增量趋势做了分形预测。     

FT-IR and XRD analysis of coal from Makum coalfield of Assam

High sulphur coal sample from Ledo colliery of Makum coalfield, Assam, India was studied using FT-IR and XRD methods. FT-IR study shows the presence of aliphatic -CH, -CH₂ and -CH₃ groups, aliphatic C-O-C stretching associated with -OH and -NH stretching vibrations and HCC rocking (single and condensed rings). XRD pattern of the coal shows that it is amorphous in nature. Function of Radial Distribution Analysis (FRDA) indicates that coal is lignite in type and there is no evidence of graphite-like structure. The first maximum in the G(r) plot of FRDA at r = 0.14 nm relates to the aliphatic C-C bond (Type C-CH=CH-C), the second maximum at r = 0.25 nm relates to the distance between carbon atoms of aliphatic chains that are located across one carbon atom. The curve intensity profiles obtained from FRDA show quite regular molecular packets for this coal. The coal was found to be lignite in nature.     

古泥炭沉积环境及其对微量元素的控制:以宁武煤田东露天煤矿11#煤层为例*

古泥炭形成时期沉积环境对煤中微量元素的富集具有重要的影响,而煤相和相关地球化学参数是指示古泥炭沉积环境的重要标志。以宁武煤田平朔矿区东露天煤矿11#煤层为例,利用煤相参数、地球化学参数和矿物学特征对东露天11#煤层的古泥炭沉积环境进行了重建,并探讨了沉积环境对微量元素富集的影响。结果表明: (1)东露天煤矿11#煤层煤相类型包括障壁岛潟湖低位沼泽相、下三角洲平原低位沼泽相和上三角洲平原低位沼泽相3种类型,受海侵影响,沼泽水体pH、古盐度、氧化还原状态和水动力条件呈现动荡变化; (2)11#煤层中元素Li(平均133.50 μg/g)、Zr(平均198.12 μg/g)和Pb(平均60.76 μg/g)含量远高于世界硬煤; (3)微量元素在11#煤层剖面中表现为2种不同的组合,即Li-Zr-Nb-Ta-Hf组合和Pb-Cu-Ga-Ge-Tl-REY组合,前者主要在DLT-11-2、DLT-11-6和DLT-11-10这3个层位富集,这些层位具有相似的沉积环境,为海水(咸水)、酸性、缺氧—还原、水动力较强、硫含量相对较低的障壁岛—潟湖低位沼泽相,而后者主要在DLT-11-0、DLT-11-4和DLT-11-8这3个层位富集,沉积环境也相似,为海水(咸水)、碱性、氧化或缺氧、水动力较弱、硫含量相对较高的下三角洲平原低位沼泽相。该成果将为含煤盆地关键金属矿产资源的勘探开发和煤炭资源的清洁利用提供理论依据。     

湘东丫江桥岩体时代与成因:来自LA- ICP- MS锆石U- Pb年代学、地球化学和Lu- Hf同位素制约

丫江桥岩体是湘东地区重要的成矿花岗岩,为精确厘定丫江桥岩体侵位时代、查明岩石成因,本文对丫江桥岩体中粗粒和中细粒黑云母二长花岗岩进行了LA-ICP-MS锆石U-Pb定年、全岩地球化学和原位锆石Lu-Hf同位素分析。获得LA-ICP-MS锆石U-Pb年龄为213.0±1.2Ma(n=12,MSWD=0.67)和212.1±1.2Ma(n=14,MSWD=0.09);岩石SiO_2含量为70.39%～72.88%和73.19%～74.85%;K_2O+Na_2O值为6.94%～7.95%和7.58%～7.96%;K_2O/Na_2O比值为1.25～1.70和1.45～1.58,A/CNK比值为1.05～1.07和1.07～1.09。稀土元素配分模式右倾,轻、重稀土分馏明显,(La/Yb)N值为13.76～24.52和7.12～11.01;负Eu异常,δEu值为0.34～0.61和0.26～0.33。富集Rb、K、Pb等大离子亲石元素,亏损Ba、Sr、Eu和高场强元素Nb、Ta、Ti等。锆石ε_(Hf)(t)值为-7.01～-0.90和-6.38～+6.85,二阶段Hf模式年龄(t_(DM2))为13.1～16.9Ga和12.7～16.6Ga。上述结果表明黑云母二长花岗岩为印支晚期岩浆活动产物,属弱过铝质花岗岩,岩浆主要来源于中元古界地壳物质重熔,可能有少量地幔物质参与。结合前人研究成果认为,黑云母二长花岗岩形成于后碰撞伸展的构造背景下,地壳减薄和压力降低以及地幔物质上涌的共同作用,导致地壳部分熔融形成花岗质岩浆,岩浆侵位冷却结晶,形成花岗岩体。     

民用燃煤排放颗粒物中金属元素组成及单颗粒分析

借助稀释通道采样系统,采集了5种民用煤(3种块煤、1种蜂窝煤和1种煤球)燃烧排放的PM2.5和单颗粒样品.利用ICP-MS分析了PM2.5中16种金属元素(Mg、Al和K 3种轻金属;V、Cr、Mn、Fe、Co、Ni、Cu、As、Rb、Sr、Cd、Ba和Bi共13种重金属)的含量,并运用TEM和SEM-EDX研究了燃煤...     

Mineralogical and elemental variation of coal from Alberta, Canada: an example from the No. 2 seam, Genesee Mine

Mineralogy and elemental contents were determined on 18 samples from a vertical profile of the No. 2 seam, Genesee mine, AB. The samples analyzed consist of coal, coaly shale, shaly coal, carbonaceous shale, shale, mudstone and siltstone. Proximate analysis was determined on all samples. Elemental analyses were determined by instrumental neutron activation analysis (INAA) for all elements except As, B, Cd, Hg, Mo, Pb, Se (Atomic Absorption) and B, Ba, Be, Co, Cr, Cu, Li, Mn, Nb, Sr and V (inductively coupled plasma-emission spectroscopy, ICP-ES). Samples were low temperature ashed (LTA), X-ray diffraction (XRD) and X-ray fluorescence (XRF) were used to determine quantitative major mineralogy. Accessory mineralogy was determined with Scannining Electron microscope/energy dispersive X-ray analyzer (SEM/EDX) on four samples. In general, the coals in the Genesee mine are within the low end of the range for trace element contents given by Swaine [Swaine, D.J., 1990. Trace Elements in Coal. Butterworths, London, 278 pp.] for most coals. High contents of Cr (9–2620 ppm) and Ni (1–1440 ppm) can be related to an increased amount of a Cr–Ni–Fe oxide (chromite–magnetite?) likely derived from ultrabasic diatremes in the Golden-Columbia Icefields, BC area. The No. 2 seam of the Genesee mine can be divided into two geochemical cycles on the basis of mineralogy, trace element contents and rare earth element (REE) behavior. Cycle I consists of quartz, calcite and kaolinite, lower trace element contents, REE slightly enriched in high rare earth elements (HREE), and thick coal with few partings. Cycle II consists of quartz, calcite, kaolinite, illite, mixed layer and/or expandable lattice clays, feldspar, gypsum, calcium aluminum sulfate hydrate, clinoptilolite, calcite and diopside, higher trace element contents, REE slightly enriched in light rare earth elements (LREE) and thin coal with a greater frequency of partings. The differences between the two geochemical cycles can be accounted for by a decreasing stability of the peat-forming environment resulting from an increasing fluvial influence and volcanogenic input.     

Characteristics of Hydrogen-rich Coals in Southern China: Implications from Organic Geochemistry and Carbon Isotopic Compositions

The organic geochemical characteristics of hydrogen-rich coal in southern China were investigated synthetically through organic geochemistry and carbon isotope analyses.The results showed that the hydrogen contents of the test samples were more than 5.0% and the H/C atomic ratios were between 0.76-1.06.Samples were found to be composed mostly of Type Ⅱ-Ⅲ℃ kerogen,consistent with good hydrocarbon-generation potential.The R_o(0.54-1.10%)and T_max(430-453℃)values imply that the hydrogen-rich coals were in low maturity to mature stages.Stable carbon isotopic ratios(δ¹³C_org)of the samples used varied from ?24.5‰ to ?23.4‰,the barkinite content ranging from 13.9% to 83.3%,indicating a predominantly terrestrial origin with marine influence during coal formation.Some organic geochemical parameters showed corresponding changes as the hydrogen content increased from 5.0% to 7.0%,however,the source inputs changed significantly when hydrogen content was greater than 6.0%.Terrestrial higher plants gradually become predominant within the coal-forming materials,whereas this dominant position is not apparent at lower hydrogen contents,which is attributable to the strong seawater effect during the hydrogen-rich coal formation process.     

Depositional Environment and Lithofacies Analyses of Eocene Lacustrine Shale in the Bohai Bay Basin: Insights from Mineralogy and Elemental Geochemistry

The effect of various depositional parameters including paleoclimate, paleosalinity and provenance, on the depositional mechanism of lacustrine shale is very important in reconstructing the depositional environment. The classification of shale lithofacies and the interpretation of shale depositional environment are key features used in shale oil and gas exploration and development activity. The lower 3^rd member of the Eocene Shahejie Formation(Es₃^x shale) was sel...     

甜水海钻孔有机碳R／S分析及其反映的气候环境变化持续性

通过对进行了等时处理的甜水海钻孔有机碳含量所做的Ｒ／Ｓ分析,发现其存在明显的Ｈｕｒｓｔ现象,Ｈｕｒｓｔ楷数Ｈ为０．７４,分数维Ｄ＝２－Ｈ＝１．２６,这与太平洋深海岩芯的氧同位素分析结果非常接近。Ｈｕｒｓｔ指数Ｈ＝０．７４〉０．５,表明甜水海地区气候环境演化存在的持续性（ｐｅｒｓｉｓｔｅｎｃｅ）。甜水海地区地处青藏高原腹地,这种气候环境演化的持续特征可能是晚新生代以来青藏高原持续构造抬升活动影响的结     

铜官山铜矿床矽卡岩矿物中流体包裹体及子矿物的扫描电镜研究

通过对安徽铜官山铜矿矽卡岩矿物中的流体包裹体岩相学、包裹体显微测温分析及子矿物的扫描电镜／能谱分析(SEM／EDS)和激光拉曼探针分析(LRM)，发现石榴石、透辉石中的包裹体为流体包裹体，包裹体的均一温度(575～885℃)、盐度[w(NaCleq)13．4％～44．9％]均较高，流体包裹体中的子矿物有黄铜矿、闪锌矿、方解石、菱铁矿、钾石盐和石盐，以钾石盐最为普遍，表明流体高度富钾，具岩浆热液的典型特征。富钾流体也与该区广泛出露的燕山期高钾富碱岩体吻合。     

磷灰石裂变径迹实验流程的建立及验证——外探测器法和LA-ICP-MS/FT法

磷灰石裂变径迹定年作为揭示岩石低温热年代学的一种重要方法,能够有效重塑地壳浅部约3～5 km内数百万年以来的热演化历史,已经被广泛应用于地球科学的相关研究中。依托于中国地质科学院地质力学研究所建立的裂变径迹实验室,同时采用外探测器法和LA-ICP-MS/FT法对国际上普遍使用的Durango磷灰石进行了测定,得到2个Durango磷灰石外探测器法年龄为：32.9±1.6 Ma、31.9±2.3 Ma; 7个Durango磷灰石LA-ICP-MS/FT法年龄为：31.97±0.82 Ma、30.9±1.5 Ma、32.3±1.4 Ma、30.6±1.1 Ma、30.7±1.4 Ma、29.7±1.9 Ma、31.1±1.3 Ma,两种方法测得的年龄均与国际推荐值在误差范围内一致;此外,我们也应用这两种方法对采集于天山的花岗岩样品18HS-5进行了测试,年龄分别为126.7±3.8 Ma、126.4±3.6 Ma,两种方法得到的年龄在误差范围内一致。实验对比分析表明,实验流程可靠,可推广测试。     

中天山早泥盆世陆弧：来自花岗质糜棱岩地球化学及SHRIMP-U／Pb定年的证据

中天山巴伦台以北地区出露一套糜棱岩化的中-酸性侵入岩，元素地球化学特点表明其属于火山弧环境；锆石SHRIMP U／Pb法测试结果揭示其侵位年龄在405—416Ma间，属早泥盆世。这一研究结果显示，早在晚志留世晚期，南天山洋已开始向北俯冲，并在中天山地块南缘形成火山弧环境。至早泥盆世晚期，塔里木陆块与中天山火山弧发生碰撞。     

Metal source of gold deposits in the Jiaoxibei area,Eastern China: Insights from trace element analysis of gold and pyrite

The metal source of gold deposits in the Jiaoxibei area, eastern China, has been investigated by many researchers, but no consensus has been reached so far. In this study, three typical gold deposits, the Xinli, Jiaojia, and Dayingezhuang deposits, were selected for trace element analysis of gold and pyrite to constrain the metal source. Pyrite from these three deposits has similar morphological and compositional characteristics, and can be divided into three types: Py1 with euhedral to subhedral textures, Py2 with subhedral to anhedral textures with micro-fractures, and Py3 with subhedral to anhedral textures and intergrowing polymetallic sulfides. Among them, Py2 and Py3 were formed in the main ore-forming stage and they are the dominant host minerals of visible gold. In these deposits, visible gold occurs mainly in micro-fractures or as inclusions in Py2 and Py3. Most of the pyrite has extremely low concentration of invisible gold, indicating that visible gold in the Jiaoxibei district is not a product of the remobilization of invisible gold from earlier pyrite. Both Py2 and Py3 are characterized by low Co concentration of <100 ppm and Co/Ni ratio of <1, which are similar to those of pyrite in sedimentary rocks. Therefore, ore-forming metals of these gold deposits in the Jiaoxibei district may originate mainly from a sediment-related metal source.     

Application of multivariate spatial analysis in scale-based distribution and source study of PAHs in the topsoil: an example from Tianjin,China

Polycyclic aromatic hydrocarbons (PAHs) in soil originate from various sources under different spatial scales. Coregionalization analysis is more revealing than univariate geostatistical analysis. Scale-dependent spatial features of variables reflect different sources of spatial variability. In this study, 188 topsoil samples in the Tianjin area were collected. The contents of 16 PAHs and soil background properties were determined for all samples. A multivariate geostatistical approach was used for multi-scale spatial analysis for PAH compounds. Results show that coal combustion was the major source for the spatial distribution patterns of PAHs in the topsoil of the studied area. It worked mainly at the short-range scale (5–10 km). Significant spatial variation patterns were identified. In contrast, no significant spatial distribution trends at the nugget (0–5 km) or long-range scales (10–50 km) were seen. Long-range transport and site contamination of PAHs might not be key contributors in forming the distribution pattern of PAHs in the topsoil of Tianjin area.     

Determination of Trace Element Mass Fractions in Ultramafic Rocks by HR‐ICP‐MS: A Combined Approach Using a Direct Digestion/Dilution Method and Preconcentration by Coprecipitation

A procedure is described for the determination of thirty‐seven minor and trace elements (LILE, REE, HFSE, U, Th, Pb, transition elements and Ga) in ultramafic rocks. After Tm addition and acid sample digestion, compositions were determined both following a direct digestion/dilution method (without element separation) and after a preconcentration procedure using a double coprecipitation process. Four ultramafic reference materials were investigated to test and validate our procedure (UB‐N, MGL‐GAS [GeoPT12], JP‐1 and DTS‐2B). Results obtained following the preconcentration procedure are in good agreement with previously published work on REE, HFSE, U, Th, Pb and some of the transition elements (Sc, Ti, V). This procedure has two major advantages: (a) it avoids any matrix effect resulting from the high Mg content of peridotite, and (b) it allows the preconcentration of a larger trace element set than with previous methods. Other elements (LILE, other transition elements Cr, Mn, Co, Ni, Cu, Zn, as well as Ga) were not fully coprecipitated with the preconcentration method and could only be accurately determined through the direct digestion/dilution method.     

Kaolinite deposition from moving suspensions: The roles of flocculation,salinity, suspended sediment concentration and flow velocity/bed shear

Understanding how mud moves and deposits is essential for conceptualizing the dynamic nature of surface environments and their ancient counterparts. Experimental study has largely been pursued by civil engineers, using kaolinite as an active ingredient. Yet, applying their data to the physical comprehension of mudstone sedimentology is hampered by multiple flume configurations between labs, and data sets tailored to specific engineering needs. The need for a better grasp of underlying processes is acute, given recent flume studies that show that moving suspensions form large bedload floccules, migrating floccule ripples and bed accretion under currents capable of moving sand grains. To advance mudstone sedimentology, integrated study of suspended sediment concentration, salinity and bed shear stress on the deposition of floccules is crucial. Described here is a set of tightly controlled experiments that explored suspended sediment concentrations from 70 to 900 mg/l, freshwater, brackish and marine salinities, flow velocities in the 5 to 50 cm/s range (equivalent to 0.01 to 0.58 Pa bed shear), measured the size of in-flow and bedload floccules, and the critical velocity of sedimentation that marks the onset of sustained bedload accumulation. The critical velocity of sedimentation of kaolinite clays is in the 26 to 28 cm/s flow velocity range (0.22 to 0.25 Pa), appears insensitive to a wide range of suspended sediment concentrations and salinities, and coincides with the formation of sand-size bedload floccules. Further decrease of flow velocity/bed shear stress is accompanied by a steady increase in the size of bedload floccules. Large bedload floccules appear to form in the high-shear basal part of the flow, a phenomenon requiring further investigation. Better understanding of the mechanisms that facilitate mud deposition from moving suspensions is critical for more realistic assessments of the depositional conditions of mud and mudstones, as well as for refining predictive models for the flux of fine-grained sediments across the Earth's surface.     

Bias in the Determination of Zr,Y and Rare Earth Element Concentrations in Selected Silicate Rocks by ICP‐MS when Using Some Routine Acid Dissolution Procedures: Evidence from the GeoPT Proficiency Testing Programme

The analytical results for the modified river sediment, SdAR‐1 circulated in Round 31 of the GeoPT proficiency testing programme, revealed unexpected discrepancies for Zr, Y and most higher atomic number rare earth elements, in determinations made by ICP‐MS using acid attack digestion methods. This investigation compares these ICP‐MS results with those obtained for SdAR‐1 by three other methods: (a) ICP‐MS using fusion/sintering for sample digestion, (b) XRF analysis and (c) INAA. The distribution of results for the elements Rb, Sr, Ce, Y, Yb and Zr is examined and compared with those of the test material for Round 25 of GeoPT, Paraná basalt, HTB‐1. A substantial proportion (though not all) of Y, Yb and Zr determinations in SdAR‐1 by ICP‐MS/acid attack was variably low (sometimes very low) compared with other methods. A detailed evaluation of the procedures used to determine these results indicated that successful determinations by ICP‐MS/acid attack could be made if digestions were made at 180 °C for 48 hr using at least 2 ml HF per 100 mg of sample. We suggest that the more benign conditions (used by many laboratories) resulted in incomplete digestion of resistant minerals, such as zircon.     

西藏雄村铜金矿I号矿体赋矿凝灰岩成因探讨: 来自 岩石地球化学、Sr-Nd-Pb同位素地球化学特征的证据

雄村斑岩型铜金矿集区位于冈底斯造山带中段南缘,目前发现的Ⅰ、Ⅱ、Ⅲ号主矿体均产于含矿斑岩体及其接触带附近的凝灰岩中,本文主要对雄村I号矿体赋矿凝灰岩开展岩石地球化学特征研究。赋矿凝灰岩显示出与岛弧火山岩相似的地球化学特征,如相对富集LREE、LILE而亏损HREE、HFS以及低的I(Sr)值(变化范围为0.704163～0.705369,均值0.704907)和正的εNd(t)值(变化范围为3.7805～7.6286,均值5.904121)等,其形成与印度-亚洲大陆碰撞造山之前的新特提斯洋俯冲作用有关,产于新特提斯洋向北的洋内俯冲作用而形成的岛弧环境。赋矿凝灰岩起源于岛弧底部的新生玄武质岩层的部分熔融,源岩主要由角闪石、斜长石和少量石榴子石组成。赋矿凝灰岩、含矿斑岩体和成矿作用同属一个火山-岩浆-热液系统,赋矿凝灰岩为成矿提供了必要的围岩外部因素,是矿区重要的控矿因素,也是一个重要的找矿地质条件。在雄村矿区及其外围,侵位于凝灰岩中的斑岩体应该是今后找矿评价的重点区域。     

A statistical analysis of the distribution of cordierite and biotite in hornfels from the Bugaboo contact aureole: implications for the kinetics of porphyroblast crystallization

The three‐dimensional disposition of cordierite and biotite crystals in a hornfels from the contact aureole of the Bugaboo Batholith is quantified using high‐resolution X‐ray micro‐computed tomography and global as well as scale‐dependent pattern statistics. The results demonstrate a random distribution of cordierite and biotite crystal sizes for all scales across the entire rock volume studied indicative of interface‐controlled prograde metamorphic reaction kinetics. The reaction considered responsible for the mineral assemblage and the formation of cordierite and biotite in the hornfels is Ms + Chl + Qtz = Crd + And + Bt + . Rock‐specific phase equilibria point to metamorphic conditions of ~520 –550 °C and 3 kbar for this reaction. The common approach to approximate the shape of crystals as spherical underestimates the influence of the Strauss hard‐core process on rock texture and may be misinterpreted to reflect ordering of crystal sizes by inhibition of nucleation and growth commonly associated with diffusion‐controlled reaction kinetics. According to our findings, Strauss hard‐core ordering develops at length scales equal to and less than the average major axis of the crystal population. This is significantly larger than what is obtained if a spherical crystal geometry would be assumed, and increases with deviation from sphericity. For the cordierite and biotite populations investigated in this research, Strauss hard‐core ordering developed at length scales of up to ～2.2 and 1.25 mm, respectively, which is almost 1 mm longer than the scales that would be obtained if a spherical geometry would have been assumed. Our results highlight the importance of a critical assessment of the geometrical model assumptions commonly applied in the three‐dimensional analysis of crystal size distributions, and underline the need for a quantitative understanding of interface processes in order to appreciate their role in the kinetics of contact metamorphic reactions and rock texture formation.     

盆山结构与油气分布——以四川盆地为例

根据四川盆地与周缘造山带地貌学、深浅部结构构造及动力学机制等, 其盆山结构可分为板缘(龙门山、米仓山和大巴山)突变型和板内(齐岳山、大娄山和大凉山)渐变型两类。板缘突变型盆山结构具有显著深部结构差异性,浅部构造具典型冲断带(山)和前陆盆地(盆)二元结构,其盆山耦合关系主要受控于深部结构的差异性和造山带的形成演化过程,现今山盆地貌反差大,地形坡度陡,盆山边界明晰。板内渐变型盆山结构, 则深部结构特征相似,浅部构造具挤压-坳陷结构、不发育大规模冲断推覆,现今山盆地貌反差小、盆山边界不清, 盆山为渐变过渡关系,其盆山耦合关系主要受控于邻区(盆外)的构造变形和盆内沉积盖层中多层次滑脱作用。不同盆山结构主要通过对现今四川盆地保存条件的影响而控制现今油气分布。四川盆地现今(残存)大中型油气藏和天然气探明储量的大部分主要分布于突变型盆山结构区,尤其是秦岭构造变形控制域。