浅析湘南地区锰矿矿源物质来源

简述湘南地区表生氧化锰矿矿源层的分布及岩性特征，讨论矿源层与构造及岩相古地理的关系。     

Comparison of the Langrangian Footprint

We compare flux and concentration footprint estimates of athree-dimensional Lagrangian stochastic dispersion modelapplying backward trajectories with the results of ananalytical footprint model by Kormann and Meixner.The comparison is performed for varying stability regimesof the surface layer as well as for different measurementheights. In general, excellent correspondence is found.     

三江源地区水资源的涵养和保护

分析了三江源区水资源现状,论述了建立水资源三级保护区的意义、作用和划分方案,实施林草植被的保护和恢复的水文生态效益及健全水资源补偿机制的必要性。     

New geochemical data from the Nigerian sector of the Chad basin: implications on hydrocarbon prospectivity

Organic geochemical studies have been carried out to assess the qualities of source rocks penetrated by four wells (Kemar-1, Murshe-1, Tuma-1 and Ziye-1) in the Nigerian sector of the Chad basin. The Chad basin is a large intracratonic basin in Central West Africa. Commercial hydrocarbon accumulations have been discovered in some sectors of the basin outside the Nigerian border in a structurally related contiguous basin. Fair to poor quality source rocks are inherent in the sequences penetrated by the studied wells. About 80% of all samples have their total organic carbon (TOC) contents more than 0.5 wt.%, the minimum limit for hydrocarbon generation. Juxtaposition of the hydrogen indices against the TOC and T_max indicates that the source rocks are entirely gas-prone. However, biomarker chromatograms and extract vs. TOC plots indicate the presence of oil shows in Ziye-1 well at a depth of 1210 m. Although generated hydrocarbons (wherever they have accumulated) would be overwhelmingly gaseous, gas is the energy of the future. The gas resources of this part of Nigeria's inland basins can be economically exploited through policies that will increase the tempo of gas-utilization projects and the construction of a national grid of gas pipelines with nodal points of input and output.     

GPS/GLONASS组合测量误差简介

GLONASS与GPS导航定位技术原理相似，GPS／GLONASS组合测量由于可见卫星数目的增加，可以提高测量的精度、可靠性、完备性。着重介绍了GPS／GLONASS组合测量中的主要误差源及其性质并给出相应的影响量级。     

内蒙古中西部地区震源参数和场地响应反演

采用Atkinson方法，基于遗传算法，利用呼和浩特数字地震台网7个子台记录的9次质量较高的地震事件资料，计算了内蒙古中西部地区的品质因子Q值和非弹性衰减系数c（f）。在所研究的频率范围内，前者和频率．厂有很好的线形关系：Q（f）=116．8f^1.000后者与频率．厂的变化关系不明显。在此基础上采用Moya方法反演了7个地震台的场地响应和地震的震源参数，并对它们之间的相互关系进行了讨论。结果显示在所研究的频率域内7个基岩台站的场地均不同程度的存在放大作用，其次震源参数间具有较好的线性关系。本文还详细介绍了Atkinson方法和Moya方法的原理和计算步骤。     

Study on the Source Parameters of Earthquakes in the Middle Eastern Area of North Tianshan in Xinjiang

INTRODUCTIONThe study of source parameters is usually based oninversionfromobservational seismic waveformdata.Seismic wave affected bygeometric spreading,inelastic attenuation,scatteringandsite effects ofthe mediumontheir way fromsource to station.Therefo…     

Land degradation in the source region of the Yellow River, northeast Qinghai-Xizang Plateau: classification and evaluation

Land degradation imposes a great threat to the world. It is not merely an environmental issue, but also a social and economic problem. Land desertification is among the main aspects of environment changes in the source region of the Yellow River. Previous studies focused on water resource utilization and soil erosion, but land degradation in the source region of the Yellow River even the whole Qinghai-Xizang Plateau received little attention. Based on the data obtained by field investigation and TM satellite images of 2000, this study provides the classification and evaluation information of the land degradation in the source region of the Yellow River. There are six types of land degradation in this region: water erosion in the northern mountains around the Gonghe Basin, sandy desertification in the Gonghe Basin and Upland Plain Area, aridization in the lower reaches, salinization in the Gonghe Basin, vegetation degradation in the intramontance basin and freezing and thawing erosion in the high mountains. The total degraded area is 34,429.6 km², making up 37.5% of the land in the study area. Finally, land degradation in the source region of the Yellow River was evaluated according to changes in the physical structure and chemical component of soils, land productivity, secondary soil salt and water conditions.     

江苏栖霞山矿床铜的来源探讨

江苏栖霞山铅锌银多金属矿床是目前华东地区规模最大的铅锌银多金属矿床,位于长江下游沿江断褶带的宁镇断褶束西端,走向长约8 km,面积约25 km2。矿区自西向东包括西库、甘家巷、北象山、虎爪山、平山头、三茅宫等六个矿段,目前正处于开采阶段的为虎爪山矿段。矿体主要沿纵向断裂带（F2）、不整合面、北西向横断裂、层间错动和层间裂隙、古岩溶构造等呈似层状和不规则状（囊状、脉状和层状）分布。赋矿地层为上泥盆统至下二叠统,其中石炭系黄龙组（C2h）碳酸盐岩地层为最主要的赋矿层位。其矿石矿物主要为方铅矿、闪锌矿和黄铁矿,次为菱锰矿、黄铜矿、磁铁矿等。自实施危机矿山接替资源找矿和老矿山找矿工作以来,矿山找矿效果明显,新增资源量达到中型以上规模,除主攻矿种铅锌矿以外,新发现矿体伴生的有益组分Au、Ag和Cu含量较高,伴生Cu金属量达到1.53万吨,且向深部有明显升高的趋势。在找矿勘查布设的42勘探线和46勘探线可独立圈出1层Au矿体、2层Cu-Ag矿体、3层Ag矿体和1层Cu矿体,Au品位普遍在0.2 g以上,Ag品位多大于10 g/t,Cu品位多大于0.2%。因此,矿区深部具有寻找铜、金、银的前景。本文通过搜集前人研究的基础资料和矿区钻孔取样分析数据,对铜的来源作初步的分析,试图厘清栖霞山矿床铜的物质来源,对于指导深部Cu等伴生有益组分的进一步找矿提供一些科学的依据。     

扬子西缘乡城-丽江结合带燕山期斑岩Mo多金属矿床成矿系统

位于扬子陆块西缘与西南三江造山带结合部位的乡城-丽江地区,北起四川乡城经云南格咱南至丽江地区,在印支期斑岩铜矿带上新发现叠加了燕山期斑岩Mo多金属成矿作用,形成乡城-丽江斑岩Mo矿带。受印支期古特提斯洋盆闭合后地壳缩短与加厚的影响,燕山晚期下地壳发生拆沉作用,导致后碰撞型花岗质岩浆侵位,发育了Mo多金属成矿作用,并构成斑岩成矿系统。岩石地球化学特征表明,燕山晚期含矿斑岩具高硅(SiO_2=66.29%~79.36%)、高碱(K_2O+Na_2O=5.07%~9.24%)、富钾(K_2O/Na_2O=0.71~2.13)的特点,属于高钾钙碱性岩石系列。岩石富集轻稀土元素(LREE),具有负δEu异常;微量元素具富集大离子亲石元素K、U、Th、Rb,亏损高场强元素Nb、Ta、P、Ti的特征;大离子亲石元素的富集和Nb、Ta等高场强元素的亏损,表明形成这些岩体的岩浆主要来自地壳,具有造山带花岗岩的地球化学特征。区内代表性含矿斑岩相似的地球化学组成及分布特征表明,乡城-丽江结合带燕山晚期的成矿斑岩是由同源岩浆分异演化而来。成矿系统的分析表明,燕山晚期主要含矿斑岩成矿物质以壳源为主,但具有少量地幔物质的加入,成岩成矿物质来源具有相似或一致的源区特征。在成矿元素的组合上,由成矿斑岩体向外带表现出W、Mo→W、Mo、Cu→Pb、Zn、Ag的演化趋势。研究表明,本区燕山晚期花岗岩浆的侵入及Mo多金属成矿作用并不是独立或个别的成矿事件,而是纵跨义敦岛弧、甘孜-理塘结合带及扬子西缘的带状成矿活动,属于区内与燕山晚期岩浆侵入作用相关的统一斑岩成矿系统。