地震勘探技术在深部找煤中的应用

成矿理论与勘探实践证明,东部一些老矿由于勘探深度、范围的限制以及认识上的局限,在矿区深部、周边仍有一些矿未能发现和查明,其中相当一部分仍具有找矿潜力;而寻找西部新的煤炭资源是国家“稳定东部发展西部”战略需要。针对中国东西部不同的地质条件和勘探目标,其地震勘探野外施工方法及资料处理原则有所差异;而资料解释在东部以查明地层赋存形态、煤层赋存范围、构造发育特征为主,西部则以寻找煤系地层波阻抗差异明显、连续性好的反射波组为解释重点。地震勘探技术在中国东西部的二个典型地震时间剖面佐证了其在深部找矿的应用效果。     

甘肃大泉水——白沙岘矿区含煤地层及煤层赋存特征

大泉水-白沙岘矿区位于甘肃省景泰县境内,在大地构造位置上处于北祁连加里东褶皱带东段,区内含煤地层为下石炭统靖远组和上石炭统羊虎沟组,属海陆交互相含煤沉积,根据岩性、岩相特征可划分为两个沉积旋回。该矿区主要可采煤层煤．层组赋存于羊虎沟组,厚1．71～9．00m,沿走向由西向东厚度变小,在大泉水井田可采厚度主要分布在V线以西,其东区段只是零星分布且不可采;在白沙岘井田煤层总厚度为2．99～5．15m,厚度变化小,属稳定煤层。煤：层组赋存于靖远组,仅分布在大泉水井田,厚1．33～8．88m,沿走向由西向东呈长透镜体状,西段和中段煤层发育较好．V线以东区段煤层变薄并出现无煤区。     

靖远矿区采煤沉陷区复垦综合评价方法研究

以靖远矿区为例,从土地复垦和恢复生态学的角度出发,建立了靖远矿区采煤沉陷区复垦综合评价系统,选择土壤条件（土层厚度、土壤质地、有机质含量、土壤水分）、地形改造条件（地面坡度、地表破坏程度、改造难易程度）、气候及水文条件（年降雨量、灌溉条件）作为分类及评价因子对复垦潜力进行评价。将采煤沉陷地分为四种潜力区,对每种潜力类型区的复垦开发利用方向进行了优化设计,从理论上和实践上对靖远矿区采煤沉陷地的复垦能力以及复垦过程中用地结构的优化作了探讨,以期对当地沉陷地的复垦提供一定的科学依据。     

Probabilistic seismic hazard evaluation in underground mines

Stress concentrations produced by rock deformation due to extraction in underground mines induce seismicity that can take the shape of violent and quite dangerous rockbursts.The hazard evaluation presented in this paper is based on a Bayesian probabilistic synthesis of information determined from mining situations during excavation, with previous and present data from microseismicity and seismoacustics.The method proposed in this study is an example of time-dependent on-line seismic hazard evaluation. All results presented were obtained retrospectiely for different underground coal mines in Poland and Czechoslovakia.On leave from Institute of Geophysics, Polish Academy of Sciences 01-452 Warszawa, ul. Ksiecia Janusza 64, Poland.     

珠江口盆地西江主洼油气差异分布机制

西江主洼是珠江口盆地一个低勘探程度洼陷，油气差异聚集特征明显，但其机理不清。本文在断陷盆地油气成藏理论指导下，利用研究区地质、地球物理和地球化学等资料，开展了烃源岩、断盖组合、储集体系和运聚模式等方面的研究。结果表明，裂陷期沉降、沉积中心有序迁移，造成主力烃源岩自东向西由文四段迁移至文三段、文一+二段，控制东、西部油气差异分布。恩平组区域性泥岩发育且晚期断裂缺乏，导致油气纵向上更易聚集于下构造层；区域泥岩减薄尖灭或晚期断裂切开盖层的区域，上构造层有一定油气分布。"源-汇"类型从宏观上控制储层优劣，影响下构造层油气富集程度；"仓储"运移是控制上构造层油气规模聚集的主要模式。下构造层古近系应作为重点部署方向，东部围绕文四段、西部围绕文三段、文一+二段烃源岩构成的含油气系统展开；上构造层勘探需关注珠海组，在隆起周边寻找具备"仓储"运移模式的有利区带。     

洛安江干渠老菁湾滑坡分析

洛安江水库灌溉工程是贵州黔北万亩以上骨干工程之一,中华人民共和国成立初期建成。１９９１年＂７．５Ｆ＂洪灾,连续大暴雨,河水暴涨,倒灌暗河,产生高静、动水压力作用。岸坡岩体受不利结构面组合,发生顺层岩质滑坡,破坏干渠,严重影响灌溉。本文根据滑坡破坏情况,对滑坡产生的地质环境、滑坡特征、滑坡形成机理（滑坡形式和破坏机理,各种稳定性分析与评价）,以及产生滑坡原因进行了初步分析。     

“煤特征指数”与矿井瓦斯危险类型的关系

矿井瓦斯危险程度与煤层中瓦斯赋存状况及其泄出方式有关,并取决于多种地质条件和采掘工艺。其中,煤特征条件特别重要。本文分析了湖南省的5种矿井瓦斯危险类型以及相应的煤特征条件,提出了“煤特征指数(I_c)”这一概念。I_c是一项评价矿井瓦斯危险程度的综合指标。研究表明,矿井瓦斯危险愈严重,则其I_c值愈高。应用该项成果预测了16对矿井的瓦斯危险类型,取得了满意的效果。     

19802000北京市农业土地生产性的变动分析

根据1980、1990、2000年的统计资料和实地走访观察,本文分析了北京市乡镇一级的粮食作物、蔬菜作物和果品作物的分布格局及农业土地生产性近20年的变化。研究认为:1980年北京农业生产分布格局与土地生产性为比较典型的杜能模式;随着农业经营的多样化,1990年和2000年北京农业土地生产性呈现出多样的分布格局;北京粮食作物、蔬菜作物、果品作物的分布格局及农业土地生产性近20年的变化与此阶段的农业生产政策、农业以外的社会经济活动变化有较强的关联性;对北京以上问题的研究为验证杜能、辛克利亚、布莱昂特城市周边农业地域研究经典理论的演变提供了实证案例。     

Fluid sources for the La Guitarra epithermal deposit (Temascaltepec district, Mexico): Volatile and helium isotope analyses in fluid inclusions

The La Guitarra deposit (Temascaltepec district, South-Central Mexico), belongs to the low/intermediate sulfidation epithermal type, has a polymetallic character although it is currently being mined for Ag and Au. The mineralization shows a polyphasic character and formed through several stages and sub-stages (named I, IIA, IIB, IIC, IID, and III). The previous structural, mineralogical, fluid inclusion and stable isotope studies were used to constrain the selection of samples for volatile and helium isotope analyses portrayed in this study. The N₂/Ar overall range obtained from analytical runs on fluid inclusion volatiles, by means of Quadrupole Mass Spectrometry (QMS), is 0 to 2526, and it ranges 0 to 2526 for stage I, 0 to 1264 for stage IIA, 0 to 1369 for stage IIB, 11 to 2401 for stage IIC, 19 to 324 for stage IID, and 0 to 2526 for stage III. These values, combined with the CO₂/CH₄ ratios, and N₂-He-Ar and N₂-CH₄-Ar relationships, suggest the occurrence of fluids from magmatic, crustal, and shallow meteoric sources in the forming epithermal vein deposit. The helium isotope analyses, obtained by means of Noble Gas Mass Spectrometry, display R/Ra average values between 0.5 and 2, pointing to the occurrence of mantle-derived helium that was relatively diluted or “contaminated” by crustal helium. These volatile analyses, when correlated with the stable isotope data from previous works and He isotope data, show the same distribution of data concerning sources for mineralizing fluids, especially those corresponding to magmatic and crustal sources. Thus, the overall geochemical data from mineralizing fluids are revealed as intrinsically consistent when compared to each other.The three main sources for mineralizing fluids (magmatic, and both deep and shallow meteoric fluids) are accountable at any scale, from stages of mineralization down to specific mineral associations. The volatile and helium isotope data obtained in this paper suggest that the precious metal-bearing mineral associations formed after hydrothermal pulses of predominantly oxidized magmatic fluids, and thus it is likely that precious metals were carried by fluids with such origin. Minerals from base-metal sulfide associations record both crustal and magmatic sources for mineralizing fluids, thus suggesting that base metals could be derived from deep leaching of crustal rocks. At the La Guitarra epithermal deposit there is no evidence for an evolution of mineralizing fluids towards any dominant source. Rather than that, volatile analyses in fluid inclusions suggest that this deposit formed as a pulsing hydrothermal system where each pulse or set of pulses accounts for different compositions of mineralizing fluids.The positive correlation between the relative content of magmatic fluids (high N₂/Ar ratios) and H₂S suggests that the necessary sulfur to carry mostly gold as bisulfide complexes came essentially from magmatic sources. Chlorine necessary to carry silver and base metals was found to be abundant in inclusion fluids and although there is no evidence about its source, it is plausible that it may come from magmatic sources as well.     

Environmental aspects of selected trace metals in soils and waters surrounding Singaran Nala, Raniganj Coalfield

The Raniganj Coalfield is the oldest coalfield in India that has been continuously and extensively mined since the late eighteenth century. The present study reports a geochemical investigation and environmental quality assessment using soil and water in the area surrounding a stream, locally known as Singaran Nala （Nala means storm water drains in Bengali）, in the Raniganj Coalfield. Soil （top soil, mud, silty clay and laterite） and rock samples （sandstone and shale） were collected from the study area and were analyzed for trace metals （Cr, Cu, Fe, Mn, Ni and Zn）. Surface waters from the stream and the Damodar River as well as ground waters from hand pumps and underground mine pits were collected. Water samples were analyzed for major ions （Na^＋, Ca^2＋, Mg^2＋, Cl^-, HNO3^- and SO4^2-） and trace metals （Cu, Fe, Mn, Ni, and Zn）. Trace metal concentrations in soil samples are found higher than the average world soil composition. Nevertheless, trace metal （Cr, Cu, Ni and Zn） concentrations in soils exceed or reach the maximum allowable concentrations （MAC） proposed by the European Commission for agricultural soils. In particular, Ni concentrations exceed the typical value for cultivated soils. Chromium, Cu and Ni concentrations in laterite and Cr concentration in topsoil exceed the ecotoxicological limit.