从成矿和变形时代的不耦合现象探讨康古尔金矿的成因

位于塔里木盆地北缘的康古尔金矿出露于秋格明塔什-黄山巨型韧性剪切带中部，长期以来被当作剪切带型金矿加以研究。通过初步的同位素年代学研究却发现了成矿和变形时代的不耦合现象：康古尔金矿成矿时代在290Ma左右，而秋格明塔什-黄山韧性翦切带剪切变形时代在225～236Ma。如果认定康古尔金矿成矿作用发生在海西期，则发生于印支中-晚期的韧性剪切变形作用不仅不是康古尔金矿成矿作用的主因，而且对金矿的改造作用也是有限的。因此，康古尔金矿不能被称为剪切带型金矿。     

东天山康古尔剪切带型金矿床成矿作用动力学研究

对康古尔剪切带型金矿成矿体系地质地球化学特征研究后认为:康古尔金矿形成于脆韧性剪切变形和脆性变形阶段;康古尔金矿热液成矿反应体系包括成矿反应、控制反应及缓冲控制反应3类;该金矿石英位错密度法所测成矿湖构迨差异应力值为101~133MPa,并呈周期性演化,同时成矿反应热力学性质和反应进行的程度受所处的地质环境和构造动力学条件的制约。     

新疆哈密野马泉西金矿区资源量数据集

康古尔塔格韧性剪切带是金矿重要控矿带,产有康古尔、马头滩、石英滩等重要矿床。野马泉西金矿即位于该韧性剪切带的东延苦水-雅满苏韧性剪切带上,属韧性剪切带控矿型金矿。本文在野外地质调查基础上采集了野马泉西金矿探矿工程坐标、工程内样品的分析测试成果等数据,采用地质块段法对野马泉西金矿资源量进行了估算,形成了数据集。数据集测试样品均委托有国家甲级资质的测试中心进行,内外检合格率90%以上,数据质量可靠,对周边同类型矿床的资源量估算具参考意义。     

东天山大型韧性剪切带基本特征与金矿预测

东天山大型韧性剪切带即秋格明塔什-黄山韧性剪切带,规模宏大,东西长逾600km,宽5～20km。变形标志明显,分四期变形。应变测量、岩组分析、剪切位移量计算、同位素测年等定量分析表明：①以平面单剪应变为主,稍晚向伸长应变转化;②存在逆冲剪切和脆-韧性变形转换;③剪切位移量在75km以上;④变形时代在300～250Ma之间,高峰期在285～265Ma,属海西中晚期。它是康-黄断裂带的重要组成体,控制着康古尔塔格金矿带的空间展布。据现有大中型金矿研究建立了区域脆-韧性变形转换带结构模式和金矿预测模式,可有效指导找矿勘探。     

东天山康古尔-黄山剪切带的活动与成矿:对区域找矿勘查的指示SCIEI北大核心CSCD

中亚造山带在显生宙期间经历了强烈的陆壳增生与改造作用,其地壳增生过程和成矿作用复杂多样。晚古生代的天山以大规模走滑剪切变形、同构造岩浆和多金属成矿作用为显著特征,是中亚造山带增生汇聚作用的典型地区。前人的研究主要关注于剪切带起源与演化时限、变形特征或独立矿床的典例剖析,缺乏针对剪切带演化与成矿时空联系的综合研究。本文选取天山康古尔-黄山剪切带出露的代表性矿床——康古尔金矿和红山南金矿,开展金矿石中绢云母^(40)Ar/^(39)Ar定年研究,并结合前人报道的年代学数据来探讨金成矿与大规模剪切活动的时空联系,从而揭示区域差异性隆升与成矿作用的耦合关系。定年结果显示,康古尔金矿的成矿时代为264.8±1.7Ma,而红山南金矿的成矿时代为261.5±1.5Ma,与康古尔-黄山剪切带右行走滑运动时间(约279~249Ma)一致。基于康古尔-黄山剪切带西段和东段在区域地质、动力学背景、岩浆作用时间、右行走滑运动的相似性和矿床空间分布的差异性,本文认为康古尔-黄山剪切带中西段的岩浆镍铜硫化物矿床和(中成至深成)造山型金矿床可能尚未出露,深部找矿潜力大,而东段出露深度大,岩浆铜岩浆镍铜硫化物矿床分布广,但中-浅成造山带金矿剥蚀殆尽,深部潜力不足。综合区域构造演化历史,本文认为康古尔-黄山剪切带的东-西差异是天山-北山三叠纪斜向汇聚所引起的区域差异性隆升导致,而差异性隆升则是区域内现今构造变形和矿床空间分布分布巨大差异的主要原因。     

新疆东天山觉罗塔格带中康古尔金矿床成因的再认识

东天山觉罗塔格构造带中康古尔金矿因其独特的成矿地质特征,成因一直备受争议。文章立足于康古尔金矿地质特征,结合前人的研究资料,通过探讨觉罗塔格带的构造演化,重新审视康古尔金矿的成因。笔者总结了觉罗塔格构造带晚古生代地层时代及火山-沉积建造特征,认为晚古生代早期大洋板块向北俯冲,发育奥陶纪-泥盆纪弧火山岩及火山-沉积岩系,石炭纪康古尔洋发生双向洋-陆俯冲,在两侧形成对称岛弧带,局部平稳拉张环境为铜-铅-锌-金成矿的有利环境。野外地质观察及室内研究结果表明其成因不仅仅与韧性剪切作用有关。康古尔金矿体位于海相安山岩、凝灰岩的交替部位,上部富金-中部铅锌-下部富铜的金属分带特征,与VMS矿床特征一致。矿体呈板状且与围岩截然接触,明显受挤压变形的网脉状矿化表明矿体形成早于韧性剪切作用。矿床地球化学特征表明,康古尔金矿成矿作用具有多期多阶段性。通过详细对比康古尔金矿和造山型金矿、小热泉子VMS铜矿的特征,笔者认为康古尔金矿具有原生VMS矿床的特征,并且被二叠纪韧性变形所改造,为喷流沉积-变质热液改造型富金多金属矿床。     

新疆东天山石东金矿床成因及找矿标志

康古尔韧脆性剪切活动控制着东天山二叠纪大规模的金成矿作用。新发现的石东金矿位于东天山康古尔韧性剪切带西段,赋存于石炭系凝灰质砂岩与石炭纪正长斑岩接触带。根据该矿床矿物共生组合和蚀变类型成矿过程可分为黄铁矿-绢云母-石英阶段(Ⅰ)、石英-多金属-自然金阶段(Ⅱ)和绿泥石-方解石-石英阶段(Ⅲ),主成矿阶段(Ⅱ)以粗大石英硫化物脉、中温热液蚀变为特征。载金硫化物及自然金电子探针数据显示该矿床与中低温变质热液活动关系密切,认为是二叠纪康古尔韧性剪切活动过程中形成的金矿床。石东正长斑岩(平均K₂O=8.8%)富集大离子亲石元素且具有较低的Mg#值(平均为30.8),认为其起源于康古尔增生杂岩部分熔融,与石东金矿没有直接成因联系。康古尔剪切带内地层-岩浆-构造活动均对二叠纪大规模金成矿事件有贡献,石炭纪碱性花岗侵入体与二叠纪脆-韧性变形是重要找矿标志。     

新疆鄯善县康古尔金矿带小尖山金矿地质特征及找矿标志

新疆鄯善县康古尔金矿带小尖山金矿位于星星峡谷带—旱山微板块中的雅满苏-红石山-黑鹰山晚古生代陆内裂谷带内康古尔金矿带的东部,产于苦水大断裂南侧的巨型韧性剪切带内,具有明显韧性剪切带控矿作用。矿体分为2类:蚀变岩型金矿、石英脉型金矿。矿区初步圈定了3条较具规模的蚀变岩型金矿体和2条石英脉型金矿体。其中,蚀变岩型金矿是主要矿床类型,赋存于安山质凝灰岩与英安质凝灰岩的接触带上安山质凝灰岩一侧,整个矿带受苦水断裂之次级韧性剪切带控制。通过综合分析,初步认为该区金矿属于与韧性剪切带有关的中—低温热液型金矿床,并总结了控矿构造、容矿岩石、岩浆岩、地球化学、热液蚀变等5个方面的找矿标志。     

东天山红石金矿床石英Rb-Sr同位素定年

红石金矿床产于东天山秋格明塔什—黄山韧性剪切带中,其成矿作用主要受韧性剪切带控制.前人通过金矿石绢云母Ar-Ar法将该矿床主成矿时代限定在254 ～ 259Ma之间,本文从讨论Rb-Sr法测年在韧性剪切带型金矿成矿时代研究中的可行性角度出发,对红石金矿主成矿期形成的金矿石进行石英流体包裹体Rb-Sr法测年.Rb-Sr法测年得到等时线年龄为257±4Ma,n(87Sr)/n(86Sr)=0.70997±0.00016.该年龄位于红石金矿床254～259Ma的主成矿时代范围内,说明石英流体包裹体Rb-Sr测年对于解决韧性剪切带型金矿床成矿时代具有很好的可行性.另外,红石金矿床与同一剪切带内的康古尔金矿在成矿时代、空间位置关系以及成矿物质来源等方面均具有一致性,认为红石金矿与康古尔金矿属相同成矿事件的产物.通过分析红石金矿床成矿时代、韧性剪切带作用时代、右行走滑以及后期的冷却降温作用时代的关系,推测红石金矿床及其剪切带内所在的康古尔等金矿床成矿作用主因是秋格明塔什—黄山韧性剪切带内晚期的右行走滑剪切变形及走滑作用后的快速抬升和缓慢冷却作用.从韧性剪切带型金矿成矿类型来看,属于早期韧性剪切变形,后期脆—韧性变形、成矿作用叠加这一类型.     

东天山康古尔塔格金矿带构造与成矿规律

康古尔塔格金矿带是近几的新疆东天山境内发现的重要成矿带，以康古尔塔格－黄山断裂为一级板块边办，其南发育晚古生工岛弧系和巨型韧性剪切带，后者东西延伸数百ｋｍ，强弱应变相间，分四期变形，第二，三期变形与金矿关系最为密切 。     

CSAMT 法在辽西康杖子区深部探矿中的应用

可控源音频大地电磁法(CSAMT)具有探测深度大、横向分辨率高、抗干扰能力强的特点,在深部找矿勘探中有着重要的指导意义。肖家营子铜钼矿床是辽西地区一个大型矽卡岩型金属矿床,大部分矿体是隐伏矿体,矿区外围的康杖子区与本区有相似的成矿地质环境,成矿地质条件优越.矿体与围岩电性差异明显,通过应用CSAMT,矿体具有低电阻特点,根据成果推断解释,对深部有利成矿部位进行了钻探验证,取得了理想的探矿效果,在矿区外围取得第二深度空间找矿重大突破。     

Geography in general education in Nigeria

This paper traces the development of geographic education in Nigeria and examines the views of geographers, other academics, students and the public at large about the importance of geography. Geography's value is immense despite the non-professional nature of the discipline. Nevertheless, there is a need to define geography's status and ensure career prospects for students. The Nigerian Geographical Association (from classroom teaachers to top geographers) must promote geography, improve its status in schools and universities, and continuously restructure its content and methods to address pertinent social needs.     

Trends in landslide occurrence in Nepal

Nepal is a mountainous, less developed kingdom that straddles the boundary between the Indian and Himalayan tectonic plates. In Nepal, landslides represent a major constraint on development, causing high levels of economic loss and substantial numbers of fatalities each year. There is a general consensus that the impacts of landslides in countries such as Nepal are increasing with time, but until now there has been little or no quantitative data to support this view, or to explain the causes of the increases. In this paper, a database of landslide fatalities in Nepal has been compiled and analysed for the period 1978–2005. The database suggests that there is a high level of variability in the occurrence of landslides from year to year, but that the overall trend is upward. Analyses of the trends in the data suggest that there is a cyclicity in the occurrence of landslide fatalities that strongly mirrors the cyclicity observed in the SW (summer) monsoon in South Asia. Perhaps surprisingly the relationship is inverse, but this is explained through an inverse relationship between monsoon strength and the amount of precipitation in the Hill District areas of Nepal. It is also clear that in recent years the number of fatalities has increased dramatically over and above the effects of the monsoon cycle. Three explanations are explored for this: land-use change, the effects of the ongoing civil war in Nepal, and road building. It is concluded that a major component of the generally upward trend in landslide impact probably results from the rural road-building programme, and its attendant changes to physical and natural systems.     

2010年的美国铀矿业

2010年,美国铀矿总共施工7 209个钻孔,总进尺1 493 520 m;生产铀1 628.55 t;铀矿业总支出费用为2.773亿美元,其中铀矿地勘费支出为3 450万美元,占铀矿业总费用的12.44%。铀矿地勘钻探费用为4 460万美元,占铀矿业总费用的16.08%。     

地下水环境中的硫代砷研究进展

硫代砷是富硫化物地下水中砷的重要形态,对环境和人类健康有潜在威胁。目前硫代砷研究程度尚低,本次主要针对国内外地下水（地热水）中硫代砷的存在形态,水文—生物—环境地球化学过程,样品保存,定量检测方法等方面进行研究。结论如下:pH, 氧化还原电位,硫化物含量和微生物作用等是影响地下水中硫代砷稳定存在和形态分布的重要因素。含铁矿物能与水中的硫代砷形成配位键对其进行吸附,吸附性普遍弱于（亚）砷酸盐,因此,地下水中硫代砷可能表现出更强的迁移性。用于硫代砷检测的自然水样在采集中可采取过滤,速冻,厌氧和低温短期保存的操作流程,以减缓该形态的转化甚至消失。色谱联用ICP-MS系统可用于自然水样中硫代砷的分离定量检测,紫外—可见分光光度法和X射线吸收光谱法在不同场景下也可对硫代砷进行定量和表征分析。地热水和浅层地下水中均可能存在硫代砷,由于水样中硫代砷的不稳定性,室内检测和分析难以准确反映现场过程,因此,野外样品保存技术和现场检测方法的更新可能在未来有更大研究空间,值得进一步探索。     

花岗岩地区地下水水文地质特征分析

通过对泰安市岱岳区花岗岩地区地下水的形成条件、地下水类型、分布状况、水文地质特征以及地下水补给、径流、排泄条件的分析,指出了花岗岩地区供水方向。     

Recent advances in aquaculture in Japan

Conclusions During the last ten years, aquaculture, especially mariculture has undergone remarkable expansion to counter-balance the gap between the supply and demand of fishery products in Japan. Its expansion has also been supported by the traditional preference of the Japanese people for seafood. Mariculture is now being forced to change its structure due to adverse economic circumstances such as the rise in the cost of energy, feeds and other materials for culture, low market prices, deterioration of environmental conditions, and many other factors. Before these constraints can be resolved, advanced scientific knowledge and technologies must be integrated to develop new types of aquaculture. Expansion of maricultural activities to more open-sea and off shore areas would be one route to follow. Technologies for the development of formulated diets not only for young but also for adults and larvae, establishment of feeding standards, prevention of epizootic diseases must support the establishment of modern aquaculture.The culture-based fisheries, or marine ranching, is becoming a subject for further development in Japan. Much research work has been conducted with a great degree of governmental support. Establishment of a net work of seedstock production farms has made it possible to carry out releasing experiments on a large scale. A newly integrated restoration system could be developed on the basis of these experiments, even though the profits resulting from the artificial restoration of stocks is not thouroughly verified at present. The commencement of a national scheme for culture-based fisheries would be a manifestation of the enthusiasm of the Japanese fish industry.     

Some Measurements of Radon in Soils and in Stream-Water in County Durham

Radon is a radioactive gas emanating naturally from uranium rich granites and shales. It may be emitted from the ground surface into the atmosphere as a gas, or it may be dissolved into stream water and transported over distance. The levels of radon gas in soils at ground surface depend on a number of factors relating to the source of the gas and to its transmission. Igneous rocks contain the highest mean concentrations of radium and uranium. The depth of cover is relevant also. Surveys over the years by the National Radiological Protection Board (NRPB) and others have indicated that the highest concentrations in the United Kingdom occur in Cornwall, Devon and northeast Scotland. However, recent reports have indicated that high concentrations of the gas may be detected in small pockets in counties outside of those considered at high risk. This survey relates to a series of measurements taken in and around Darlington, County Durham. The results showed the presence of small areas with strong concentrations of radon in soil gas, but only minor levels of dissolved gas in stream waters.     

内蒙古苏尼特地下水氟污染形成机理研究

为了研究内蒙古苏尼特地区地下水氟污染机理,本文运用水文地球化学分类方法,从水文地质、水化学特征两方面研究其地下水的水质特征、氟的起源、分布规律及污染形成机理。研究结果发现:高氟地下水的主要水质类型为HCO3—Na型,pH值在7.08～9.38之间,氟浓度与井深有关,即井越浅,氟浓度越高;地下水中氟浓度最高达14.78mg/L,5～9月地下水氟浓度相对增长率在7.8～23.1之间;F-浓度与Li+、Br-相关系数达0.89和0.82,受断层影响的深层地下水中F-浓度几乎与Li+、Br-没有相关关系,这暗示着氟来源于浅部,并受到强烈的蒸发作用影响而使水中的氟浓缩;地质调查发现该地区还有数个萤石矿存在,显微镜分析结果证实表层土壤中普遍存在CaF2,地下水中的氟来自CaF2。高氟地下水存在于潜水层,深部含水层的地下水可供开采。从断层带涌出的水对潜水层有稀释作用。