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土壤地球化学测量在智利阿尔法矿区的应用效果 总被引:2,自引:0,他引:2
土壤地球化学测量在智利阿尔法矿区的应用实践表明,土壤地球化学测量能进一步明确找矿方向,确定找矿靶区,缩小找矿范围,加快找矿步伐.在该区地质找矿中发挥了重要的指导作用,取得了较好的应用效果. 相似文献
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通过1/万不规则测网土壤地球化学测量方法在安图县金星金矿勘查区的实施,发现了一批具有找矿意义的土壤地球化学金异常。根据元素地球化学特征和土壤地球化学特征分析,结合地质成矿条件,确定有望找矿区段,并进行了槽探工程揭露,发现了金(银)矿化体,取得了较好的找矿效果。实践证明1/万不规则测网土壤地球化学测量找矿方法在本区是行之有效的。 相似文献
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内蒙东乌旗地区土壤地球化学测量及找矿效果 总被引:6,自引:1,他引:6
在东乌旗地区,用土壤地球化学测量发现了许多异常区(带)及找矿靶区,它们多与多金属矿有关,具有很大的找矿潜力.如阿尔哈达CH1、CH2、CH3、CH4号异常带,现正进行地质详查找矿;达赛脱Ⅱ-1号找矿靶区、花脑特Ⅰ-1号找矿靶区,经钻孔验证见到了工业矿体.哈巴特盖Ⅱ号异常区,土壤地球化学剖面加密测量证实为矿致异常,找矿潜力较大. 相似文献
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新疆在1∶20万比例尺的区域化探扫面中发现大量Au异常,据此找到多处大中型金矿床。为了对托里县幅1∶20万水系沉积物测量所圈定的"39乙"号异常区进行检查,开展了1∶1万土壤地球化学测量。通过合理确定研究区土壤中Au元素背景值与异常下限,直接用异常下限值圈定异常,利用岩石地球化学剖面测量进一步验证土壤异常。最终确定了土壤地球化学测量在该区找矿工作中的适用性和可靠性,圈定了2个Au异常带(4个异常区),并划定I号异常带为研究区首要找矿靶区。 相似文献
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沟系土壤地球化学测量在贵州普晴锑金矿勘查区应用与找矿效果 总被引:2,自引:0,他引:2
通过沟系土壤地球化学测量方法在普晴锑金矿勘查区中的实施,确定各元素异常下限值为Au7×10-9、Sb10×10-6、Cu200×10-6、As30×10-6,发现了一批有价值的地球化学异常,对各元素地球化学异常区的找矿潜力进行分析,结合地层、岩性等有利控矿因素综合评判主成矿元素异常、元素组合异常圈定4个找矿靶区,确定了各靶区的主要找矿矿种,对各靶区进行了必要的山地工程查证,取得了较好的找矿效果。实践证明沟系土壤地球化学测量找矿方法在本区是有效的,认识到在当前老矿区外围找矿中成矿元素弱异常、多元素组合弱异常区具有重要找矿意义。在此基础上较系统的总结了沟系土壤地球化学找矿方法步骤。 相似文献
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CSAMT法在辽西康杖子区深部探矿中的应用 总被引:5,自引:0,他引:5
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。 相似文献
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Trends in landslide occurrence in Nepal 总被引:2,自引:0,他引:2
David N. Petley Gareth J. Hearn Andrew Hart Nicholas J. Rosser Stuart A. Dunning Katie Oven Wishart A. Mitchell 《Natural Hazards》2007,43(1):23-44
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. 相似文献
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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%。 相似文献
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环境和灾害是威胁人类生存的两大挑战性问题。由人类活动导致的自然环境破坏和恶化是一个长期累积的过程,类似于人体所患的慢性疾病,对其认识和解决不仅依靠多种条件,也需要很长时间的持久努力。自然灾害的发生一般是短时间内的突然事件,类似人体的急性疾病。为最大限度地减轻自然灾害给人类社会造成的损失,需要实施事先预防、灾前预警、灾时应急和灾后重建的系统工程,其中地球科学家的责任之一是找出有效的宣传演练,使社会各界充分认识灾害的危险性,做好必要的防灾准备。最近20 a来中国的减灾实践经验还说明,为进一步提高减灾的效益,要用科学观念指导各领域的减灾工作,在国家一级层次上要实行多部门协调、多学科合作的综合管理,并注重对灾害发生的规律性研究。例如对群发性灾害链过程及其潜在影响的估计,这对制定区域性可持续发展规划具有重要意义。 相似文献
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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. 相似文献