新疆及周边国家、地区超大型矿床成矿特征和远景分析

20世纪70年代以来，由于储量特别巨大的超大规模矿床在各国和世界经济中起着越来越重要的作用，对这类矿床的勘查和研究越来越引起重视。笔者在对新疆及周边国家、地区超大型矿床研究基础上，论述了超大型矿床的时空分布特征，讨论了超大型矿床类型及其选择性，分析了成矿大地构造环境，并论证了超大型矿床资源潜力，中亚超大型矿床的若干特点。     

基本农田植树的原因及防治对策——以莱芜市莱城区张家洼街道办事处为例

近年来,基本农田植树的现象越来越严重,耕地保护的形式日益严峻。以莱芜市莱城区张家洼街道办事处为例,分析其中的原因,主要为部分农民耕地保护意识淡薄;而种树投入少却见效快;此外,还有农村劳动力减少等原因,建议要改变现状应加快政策研究,使法律更加完善;出台地方保护政策,建立奖惩制度;成立专门工作班子,采取强制措施,加大宣传力度,营造良好氛围等措施。     

莫霍面的性质及力学特征与找矿

莫霍面是地球内部的最明显的两个一级速度间断面之一,也是地球内部最接近地球表面的全球性分界面,与人类的生存环境关系最为密切,也是最有可能与地表观察的结果相联系。自从莫霍面被发现之后, 在全球性或区域性研究上都备受关注,对其界面性质的确定经过了近一个世纪,相变界面还是化学界面,仍处于争论之中。莫霍面的埋藏深度及其性质的横向不一致,在全球尺度上显示得很明显,大体与地表所见的陆—洋分布相关。本文综述了莫霍面的性质、岩石学特征、地球化学元素分布及其热力学、动力学特征,并讨论了莫霍面与找矿的关系。     

数值分析软件Mathematica在测绘中的应用

在简要介绍Mathematica软件的基础上,着重讨论了其在测绘编程计算、平差、曲线拟合、迭代运算方面的优势,并利用实例进行了分析。指出应用其强大的数值分析功能,可以使测绘公式推导、编程计算和迭代计算与分析更为便捷,使测绘人员有更多的时间和精力去从事建模方法和过程分析的研究。而目前应用该软件进行测绘研究在国内尚无许多文献报道。该软件在解决若干常规测绘问题方面有很好的应用前景。     

Conditioned duality between supercontinental 'assembly' and 'breakup' LIPs

A compilation of 178 more precise ages on 10 potential Large Igneous Provinces(LIPs) across southern Africa,is compared to Earth's supercontinental cycles,where 5 more prominent LIP-events all formed during the assembly of supercontinents,rather than during breakup.This temporal bias is confirmed by a focused review of field relationships,where these syn-assembly LIPs formed behind active continental arcs;whereas,the remaining postassembly-and likely breakup-related-LIPs never share such associations.Exploring the possibility of two radically different LIP-types,only the two younger breakup events(the Karoo LIP and Gannakouriep Suite) produced basalts with more enriched asthenospheric OIB-signatures;whereas,all assembly LIPs produced basalts with stronger lithospheric,as well as more or less primitive asthenospheric,signatures.A counterintuitive observation of Precambrian breakup LIPs outcropping as smaller fragments that are more peripherally located along craton margins,compared to assembly LIPs as well as the Phanerozoic Karoo breakup LIP,is explained by different preservation potentials during subsequent supercontinental cycles.Thus,further accentuating radical differences between(1) breakup LIPs,preferentially intruding along what evolves to become volcanic rifted margins that are more susceptible to deformation within subsequent orogens,and(2) assembly LIPs,typically emplaced along backarc rifts within more protected cratonic interiors.A conditioned duality is proposed,where assembly LIPs are primarily sustained by thermal blanketing(as well as local arc hydration and rifting) below assembling supercontinents and breakup LIPs more typically form above impinging mantle plumes.Such a duality is further related to an overall dynamic Earth model whereby predominantly supercontinent-orientated ocean lithospheric subduction establishes/revitalizes large low shear velocity provinces(LLSVPs) during assembly LIP-activity,and heating of such LLSVPs by the Earth's core subsequently leads to a derivation of mantle plumes during supercontinental breakup.     

The adoption of agroecology and conventional farming techniques varies with socio-demographic characteristics of small-scale farmers in the Fako and Meme divisions of Cameroon

This study verifies how the adoption of agroecology and conventional farming techniques varies among different socio-economic characteristics. Data acquisition involved the administering of 200 questionnaires and the organization of two focus group discussions (FGDs). The data collected were analysed using: frequencies, means, probabilities, odds and odd ratios. The FGDs were analysed using context analysis. The analyses were performed in SPSS version 20 and Wordstat 7. The results reveal that older respondents tend to adopt conventional farming techniques more than other categories due mainly to inertia or the inability to adapt to changes and their limited propensity to adopt agroecology techniques. Farmers with fewer years of farming experience are more open to agroecology related techniques due to higher inertia while those with more years of farming experience converge with older farmers who tend to prefer conventional farming. The higher the level of income, the more frequent the use of agroecology techniques. Families with more members who live and work on the farm are more open to agroecology; however, there is a limit beyond which the more the number of family members who live and work on the farm, the less the probability of adopting agroecology techniques. The higher the level of education, the greater the propensity to adopt and experiment with agroecology.     

地热资源管理与可持续发展

地热资源作为一种相对清洁的替代能源 ,越来越受到人们的重视 ,但由于地热资源不合理的开采 ,引起了一系列的环境问题 ,因此 ,地热资源保护与可持续发展显得更为重要。     

Subjective distances and spatial representations

Behavioural geography is more and more concerned with the representation of distances and spaces. This paper deals with the origins of this kind of analysis in the French- and English-speaking worlds, and with the basic theories of representation. It then develops the main arteries of research about distance and space cognition.     

减灾增益, 强化地下水的研究和人才培养

本文简要介绍了我国地下水开发利用的成就;分析了日显突出的涉及地下水的灾害性问题;提出了进一步合理开发利用地下水、除害兴利而应当进行的11个方面的科学研究;强调了培养地下水领域高级人才的必要性.     

湖泊信息采集及评价方法探讨

湖泊变化急剧,历史上缺乏准确完整的湖情资料。湖泊作为一种重要水体,越来越为人类社会所重视。湖泊的治理、开发利用与保护需要权威的湖泊基础信息作依据。结合湖北省的实际作了初步探索,提出了湖泊信息采集的6大体系20个类别100余项指标,介绍了湖泊信息采集及评价方法,较全面描述湖泊状况,具有较强的实用性。     

卵石地层的特殊性及其对基坑支护的影响分析

主要从卵石地层的特征分类、特殊结构及场内施工条件3个方面,对基坑支护结构选型及施工工艺选择进行深入、系统的分析论证,力求使在卵石地层中的基坑支护设计方案更科学、经济,使施工方法、工艺更具可操作性。     

世界气候变暖及二氧化碳埋存现状与展望*

由于CO₂大量排放而引起的全球气候变暖问题日趋严峻。21世纪环境保护受到国际社会高度关注,全球气温上升控制目标比工业革命前水平高2 ℃以内,因此必须采取积极有效措施。捕获和埋存废气中的CO₂是避免气候变化的有效途径之一,同时要求CO₂须埋存几百或几千年。埋存对环境产生的影响最小、成本较低且遵守国际法规。CO₂地下埋存的主要场所是枯竭的油气藏、深部的盐水储集层、不能开采的煤层和深海等。CO₂地下埋存可应对因能源需求增长和CO₂排放量增加带来的挑战,必将为全球资源及环境的高水平、高效益开发和可持续发展提供理论及实践依据。     

Use of clay fabric to distinguish turbiditic and hemipelagic siltstones and silts

Pliocene and Holocene siltstones and silts in outcrops from the Boso Peninsula, Japan and in cores from the East China were studied to determine distinctive characteristics of the turbiditic (Bouma E-Division) and hemipelagic siltstones and silts. Weathering characteristics, colour, grain size, and organic carbon-organic nitrogen ratio, plus clay fabric proved valuable in characterizing each unit. Clay and non-clay mineral content was uniform throughout. Clay fabric differences are pronounced. Random clay flake orientation prevails in the turbiditic interval while the hemipelagic unit has more preferred orientation. The fabric reflects different conditions of sedimentation. The turbiditic clay was deposited more rapidly in the flocculated state while the interturbidite hemipelagic clay may have formed from more slowly sedimented dominantly dispersed clay. Results suggest that clay fabric may be useful in combination with other sedimentary features in the study of mud-turbidite sedimentation.     

基于灰色关联度和主成分投影法的节水灌溉工程投资方案优选

在节水灌溉项目投资方案优选的决策过程中,所依赖的信息是＂部分完全的＂或称＂贫信息性＂,这正是多个方案优选决策的＂灰色性＂。投资方案的优选决策是一项复杂的、多项因素的工作,要考虑的目标很多,其评价因素和优选结论都具有＂不确定性＂,这实际上是一个多目标的决策问题。针对多个投资方案的优选问题,引入灰色关联度和主成分投影法,通过建立决策模型对投资方案进行优选,提高了优选的精确性和客观性,并通过实例说明该方法来解决多目标的方案决策问题是可行的。     

Hydrogeology and sustainable agriculture

 The world's population continues to grow and to require more and more food. Attempts by modern high output agriculture to meet this need have led to serious environmental problems. A more sustainable balance is now required and is being sought in a variety of ways. Hydrogeologists should continue to highlight the threat posed by agriculture to groundwater, particularly since groundwater is a hidden resource and its degradation and rehabilitation often take place slowly. But the time has come for groundwater specialists to go further and become actively involved in helping to provide practical and sustainable solutions. The agriculture of the future requires a holistic approach which balances the essential economics of food production with equally valid environmental needs, including those of groundwater. Such an approach demands cross-sectoral collaboration involving multidisciplinary research and action within an integrated policy framework. This paper reviews the current groundwater/agriculture interface and some of the attempts being made to achieve a more truly sustainable agriculture with particular emphasis on European experience. It aims to stimulate greater interest and involvement by hydrogeologists in helping to bring about realistic solutions that will enable future generations to enjoy adequate good quality food and water. Received: 9 August 1996 / Accepted: 11 November 1996     

深部找铀及湘南-桂北地区深部找铀潜景分析

概述了国内外深部找矿的研究成果,指出深部找矿是当今发展的趋势。国内外重大矿产的成功发掘,其深度均在千米以上,铀矿化垂向分布深度可达4 km以上。综合介绍了国内外勘查深大矿床的特点和条件,认为岩石-构造条件是深部矿化定位的重要因素,复式岩体、成矿系统的垂向变化、构造地球物理-地球化学异常模型是深部找矿的关键依据。综述了中国南方湘南—桂北地区深部找铀的有利地质构造条件和潜力,成矿流体是该区铀矿化的根源,白垩—第三纪重大地质事件是该区深部铀成矿的重要前提,重大地质事件引发的NE-NNE,NW向深大断裂及断陷盆地是铀矿化赋存的重要场所和勘查靶区。在已知铀矿田、成矿带勘查范围基础上,在该区进行深部探索将会获得重大突破。探讨了湘南—桂北地区深部找铀的勘查思路和方法。     

多孔结构矿物（岩石）及其环境修复材料的实用性

具有多孔结构的矿物(岩石)作为一类特殊的工业原材料，在环境修复领域的应用前景正在成为研究热点。本文从微孔的尺度、结构、形态、成分等表面固体特征出发，概括性地论述了凹凸棒石、海泡石、蒙脱石、沸石、硅藻土等十几种多孔结构矿物(岩石)在环境修复工程中用作过滤材料、吸附剂、离子交换剂和催化剂等材料时的基本特征和使用时应注意的问题。     

High- and Low-Temperature I-type Granites

Abstract: I– and S-type granites differ in several distinctive ways, as a consequence of their derivation from contrasting source rocks. The more mafic granites, whose compositions are closest to those of the source rocks, are most readily classified as I– or S–type. As granites become more felsic, compositions of the two types converge towards those of lowest temperature silicate melts. While discrimination of the two is therefore more difficult for such felsic rocks, that in no way invalidates the twofold subdivision. If felsic granite melts undergo fractional crystallisation, the major element compositions are not affected to any significant extent, but the concentrations of trace elements can vary widely. For some trace elements, fractional crystallisation causes the trace element abundances to diverge, so the I– and S– type granites are again easily separated. Such fractionated S-type granites can be distinguished, for example, by high P and low Th and Ce, relative to their I-type analogues. Our observations in the Lachlan Fold Belt show that there is no genetic basis for subdividing peraluminous granites into more mafic and felsic varieties, as has been attempted elsewhere. The subdivision of felsic peraluminous granites into I– and S-types is more appropriate, and mafic peraluminous granites are always S–type. In a given area, associated mafic and felsic S-type granites are likely to be closely related in origin, with the former comprising both restite-rich magmas and cumulate rocks, and the felsic granites corresponding to melts that may have undergone fractional crystallisation after prior restite separation. We propose a subdivision of I-type granites into two groups, formed at high and low temperatures. The high-temperature I–type granites formed from a magma that was completely or largely molten, and in which crystals of zircon were not initially present because the melt was undersaturated in zircon. In comparison with low-temperature I–type granites, the compositions extend to lower SiO₂ contents and the abundances of Ba, Zr and the rare earth elements initially increase with increasing SiO₂ in the more mafic rocks. While the high-temperature I–type granite magmas were produced by the partial melting of mafic source rocks, their low-temperature analogues resulted from the partial melting of quartzofeldspathic rocks such as older tonalites. In that second case, the melt produced was felsic and the more mafic low-temperature I–type granites have that character because of the presence of entrained and magmatically equilibrated restite. High temperature granites are more prospective for mineralisation, both because of that higher temperature and because they have a greater capacity to undergo extended fractional crystallisation, with consequent concentration of incompatible components, including H₂O.     

Non-linear connections between dune activity and climate in the High Plains, Kansas and Oklahoma, USA

Discrete dune fields are found throughout much of the Great Plains of North America, and the timing of past dune activity is often used as a proxy for paleoclimate because of the intuitive link between dune activity and a more arid climate. This research suggests that feedbacks in the soil-geomorphic system create a relationship between dune activity and climate that varies both spatially and temporally. Older eolian landforms are more resistant to activation because of the long-term accumulation of finer soil particles in a Bt horizon which retain moisture and anchor the deposit even during more arid times. Conversely, younger deposits lack these fines and are more easily reactivated. This spatially variable relationship is supported by soil stratigraphy, particle size analysis, and optical age control. Additionally, the water retention of the Bt horizons is quantifiably greater than that of the soils found in the younger dunes of the area. This complication in the relationship between eolian activity and climate is important because it suggests that caution is needed when using past dune activity as the lone proxy for paleoclimate.     

毫米波测云雷达的特点及其研究现状与展望

云在大气的能量分配、辐射传输,尤其是水循环系统中有不可忽视的作用。云探测对云物理、人工影响天气、气候变化和航空航天等领域有重要意义,是大气科学研究的热点之一。尽管目前已经发展了很多种遥感设备对云进行观测(如激光雷达、卫星、云幂仪等),但这些设备无法得到高时空分辨率的云水平和垂直结构,而毫米波雷达是云三维精细结构探测的重要工具。由于毫米波雷达具有更接近小粒子尺度的短波长,因此更适合用来探测弱云,同时毫米波雷达也存在衰减严重的缺点。介绍了毫米波雷达的特点以及其探测小粒子的优势;对比分析了其与新一代多普勒天气雷达、晴空风廓线雷达的差异,得出：毫米波雷达具有高时空分辨率,能够更精确地反映云的垂直和水平结构,比普通天气雷达更适合监测云的变化。概括了国内外毫米波测云雷达的发展现状以及在云物理研究方面的情况,并展望了国内毫米波雷达未来研究的方向。