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1.
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
2.
古昌蛇绿岩中的斜长花岗岩特征 总被引：1，自引：0，他引：1
古昌蛇绿岩中首次发现斜长花岗岩。斜长花岗岩的地质特征和岩石学、岩石化学、地球化学特征反映出异常洋脊花岗岩的属性,岩浆源自地幔,与古昌蛇绿岩中的变质橄榄岩、基性岩墙、基性熔岩的岩浆同源,是基性—超基性岩浆分异的残余,应属古昌蛇绿岩中的浅色岩组分,是蛇绿岩的端元岩石。 相似文献
3.
The Sundarbans is one of the productive mangrove wetland ecosystems in the Ganges-Brahmaputra delta in Bangladesh. The delta
is undergoing rapid ecological changes due to human activity. In the present study, surface water salinity data from 13 rivers
of the Sundarbans were collected in order to investigate the saline water intrusion in the mangrove wetlands. Results demonstrate
that saline water has penetrated the upstream area as river water salinity has increased significantly in 1976 compared to
the year 1968. The soil and river water salinity data also shows that it has crossed the water salinity threshold line in
most parts of the Sundarbans wetlands. These observations are due to the construction of Farakka Barrage in 1975, which reduced
the water discharge of the Ganges River from 3700 m3/s in 1962 to 364 m3/s in 2006. The shortage of freshwater discharge to the deltaic area is trailing active ecosystems function, especially in
the dry season in the south western region in Bangladesh. The objective of this study is to understand and analyze the present
degraded mangrove wetland ecosystems and their negative impacts. The findings of this study would contribute to the formulation
of the mangrove wetland ecosystems management plan in the Ganges delta of Bangladesh. 相似文献
4.
5.
西山岩溶水作为北京市重要的供水水源,在区域水文地质调查过程中发现西山岩溶水补给区一些样品硝酸盐浓度偏高,然而其周围岩溶水中硝酸盐浓度并未见明显变化（浓度均值为18.81 mg/L）,具点状硝酸盐源特征。岩溶含水层中硝酸盐分布特征和影响因素具有重要的研究意义。文章利用岩溶水化学和同位素分析结果研究了岩溶水硝酸盐分布和来源,利用IsoSource软件计算各来源的贡献率。结果表明:军庄—永丰屯径流区和军庄—古城—玉泉山泉径流区岩溶水中硝酸盐主要来源于生活废水、土壤有机氮矿化和大气沉降,贡献率值分别为37.1%、36.3%、26.6%;潭柘寺—四季青岩溶水中硝酸盐在潭柘寺补给区有养殖场废水下渗影响,径流区中硝酸盐含量低并发生反硝化降解作用。永定河水源硝酸盐不是岩溶水硝酸盐的主要来源。研究成果对西山岩溶水中硝酸盐的控制具有重要参考价值。 相似文献
6.
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
7.
模糊数学在岩溶储层地热资源勘探风险评价中的应用——以重庆山地型岩溶热储为例 总被引：1，自引：1，他引：0
重庆市岩溶储层地热资源丰富,开发利用历史悠久,但地热资源勘探风险较大。本文利用模糊综合评价法建立了风险评价模型,该模型中包含了热储构造开启程度、热储构造部位、沟谷切割程度、物探效果、热储埋深、热储厚度、热储岩层倾角、热异常情况、热储层位9个风险因子,每个因子划分为风险小、风险中等、风险大3级,并对其进行量化处理。最后对全市23个高隆起背斜两翼46个相对独立的山地型高隆起岩溶地热田共79个地热单元进行了地热资源勘探风险模糊数学综合评判。结果表明,有18个单元为风险小,42个单元为风险中等,19个单元为风险大。风险小的地热田一般热储汇水面积较大、补给径流循环条件好、热储顶板埋深1000-1800 m、热储厚度≥300 m、热储岩层倾角25-40°、深部裂隙较发育;风险大的地热田热储汇水面积较小、补给径流循环条件差、热储顶板埋深≥2500 m、热储厚度〈200 m、热储岩倾角〈20°176;或≥40°176;、深部裂隙不发育;风险中等地热田的地质特征则介于二者之间。评价结果较好地反映出了重庆市岩溶热储地热资源勘探风险状况。 相似文献
8.
《Applied Geochemistry》2000,15(1):13-25
The carboxylate (formate, acetate, propionate and oxalate) and common inorganic anions (F−, Cl− and SO2−4) compositions for aqueous fluid inclusion leachates from 17 mineral samples collected from various deposits have been determined using ion chromatography in conjunction with microthermometric measurements on the fluid inclusions of their host minerals. The minerals, quartz, fluorite, barite, beryl and a few `ore' minerals (wolframite, pyrite and galena), came from hydrothermal vein-type deposits in felsic igneous rocks or Archean metamorphic rocks. The results indicate that short-chain carboxylates are common components in hydrothermal fluids and can be present in considerable amounts. Formic acid (as formate) is the dominant species over other carboxylic acids. The present study raises new questions about the origin and geochemical significance of carboxylates in hydrothermal ore-forming processes. 相似文献
9.
以安徽淮北平原浅层地下水中的水质状况为研究对象,有针对性地采集了浅层地下水水样151个,应用多种方法测试了26种水样指标。综合分析结果表明:安徽淮北平原浅层地下水色度、浊度超标率小于10%;pH均值为7.6,为中性偏碱性水;HCO3—Na.Ca、HCO3—Na、SO4—Na、HCO3.SO4—Na.Mg等4种水化学类型占62.9%;硬度和TDS均值分别为481mg/L,641mg/L;Fe、Mn超标率分别为50.8%,46.9%;F-均值为1.4mg/L,低洼地势含氟矿物的溶解是导致F-局部偏高的主要原因,最高可达4.1mg/L;CODMn变化范围为1.0～3.5mg/L,有机污染程度低;三氮浓度随深度的增加而减少,农药化肥的过量使用是导致NO3--N和NH4+-N超标的主要原因,NO2--N超标19.1%,且与Fe2+浓度呈正相关关系(相关系数为0.933)。主成分分析发现,地下水的交换吸附作用、溶滤作用,原始沉积环境以及农业生产活动是影响其水质的主要因素。 相似文献
10.
花岗伟晶岩石英流体包裹体中的短链羧酸 总被引：5，自引：1，他引：4
用离子色谱法研究了某些花岗伟晶岩中石英流体包裹体浸取液的短链送终酸（甲酸、乙酸、丙酸和草酸）和无机阴离子（氟、氯和硫酸根离子）组成,同时进行了矿物包裹体流体的氢和石英的氧同位素成分测定以及显微计温学研究。结果表明,北京延庆大庄科花岗伟晶岩的石英流体包裹体浸取液中含有少量的甲酸和乙酸。花岗岩演化晚期－伟晶岩阶段的高温水热流体中可以存在短链羧酸。 相似文献
11.
This article discusses the involvement of older women and men in voluntary work in rural communities in the Netherlands. Gender,
ageing and civil society form the core concepts in the article. Politicians and policy makers in the Netherlands are worried
about the perceived decline of civil society and about the consequences of this decline for specific categories of older women
in terms of well-being and social exclusion. The paper presents the results of two surveys of involvement of older women and
men in civic organisations, voluntary work and local actions. The surveys indicate high levels of involvement of both women
and men. No gender differences are found in activity level. However, the data demonstrate the gendered nature of civil society.
Women are more engaged in informal voluntary work and informal local actions, while men are more active in formal organisations
and functions. This gender segmentation is not absolute, however. Many older women and men transgress the traditional feminine–masculine
boundaries. The surveys highlight the involvement of women and men in rural communities, but indicate lower activity levels
in urban areas. 相似文献
12.
The first observations of molybdenite in a meteorite have been made in two CaAl-rich inclusions in the Allende chondrite. The mineral occurs as single individuals completely enclosed in high Ni metal (62–64.5 wt. % Ni). The association with refractories is consistent with thermodynamic calculations which predict that Mo is a high temperature condensate even when nucleation constraints are imposed on the formation of a metal phase. Kinetic factors (including nucleation constraints) appear to have played an important role in the formation of molybdenite and the associated sulfides, magnetite and high nickel metal. 相似文献
13.
赣北中元古界双桥山群是一个完整的浊积扇体。其中计林组具有远源缺底的浊积序列、水下流动构造甚为发育、古流向单一、紫红色与灰绿色交互等特点，为外扇沉积标志。加强对计林组外扇沉积作用研究，可以大大深化赣北前震旦纪基础地质研究。 相似文献
14.
湖州市不同土壤重金属的污染现状 总被引：3，自引：1，他引：3
湖州市是主要的农产品基地，其主要土壤类型有四种，即黄泥土、青紫泥、白泥土和湖松土。样品分析表明重金属元素在黄泥土和青紫泥中较高，白泥土和湖松土中较低。大多数重金属元素相对下蜀土是富集的，超过自然背景值的元素有Cu,Cd及部门土壤中的Pb和Hg。有机质、pH值和Eh值对重金属的含量和化学形态有影响，有机质愈高，重金属的含量愈高；pH值接近中性，重金属的含量亦高。土壤的氧化条件可使大多数重金属变为高价离子，它们的化合物活性较低，但Cr^6 易被植物吸收。湖州土壤中重金属的高值点与工业污水排放和大气沉降有关。土壤中对农作物有危害的重金属元素为Cd和Hg，局部地方为Pb。 相似文献
15.
V. T. Trofimov S. D. Balykova T. V. Andreeva A. V. Ershova 《Moscow University Geology Bulletin》2012,67(4):247-252
The subsidence of buried soils in cyclic loess sequences in the Northern Eurasia Region was described. Two types of variations in the relative subsidence of the buried soils were established. The relationships between the subsidence indexes of buried soils, over- and underlying loess were studied. 相似文献
16.
Yu. F. Moroz 《Doklady Earth Sciences》2016,467(2):418-422
The revealed regularities in the behavior of the electric conductivity of the geological medium on the Shipunskii Peninsula are in qualitative agreement with the seismicity variations in the Kamchatka region. The possible nature of variations in deep conductivity is considered. 相似文献
17.
河口沉积物孔隙水营养盐分布特征及扩散通量 总被引：1，自引：0，他引：1
通过2010年夏季在李村河口潮滩区3个站位的采样分析,研究了孔隙水营养盐的分布特征,并利用Fick第一定律估算了沉积物-水界面间营养盐的扩散通量。结果表明,孔隙水营养盐在不同站位间质量浓度不同,呈现出自河口上游向下游逐渐降低的分布趋势。NH4+-N质量浓度为26.21~53.10 mg/L,是孔隙水中营养盐的主要组分。沉积物中有机物的降解反应主要在还原状态下进行,营养盐质量浓度在垂向上的变化受有机质含量及沉积物氧化还原环境改变的综合影响。除NO3--N外其他营养盐均由沉积物向上覆水体扩散,沉积物是底层水体营养盐的重要来源。 相似文献
18.
洪泛湿地系统地表水与地下水转化研究进展综述 总被引：1，自引：0，他引：1
洪泛湿地地表水(SW)与地下水(GW)转化关系研究对综合管理湿地水资源具有重要的理论和实践意义。通过洪泛湿地SW-GW转化研究进展的综述,可深入了解国内外SW-GW转化研究的发展过程,有利于把握国际研究的主流趋势,系统掌握该方面研究的前沿手段。总结得出,洪泛湿地是我国诸多生态系统中特色突出的水文系统,其独特的水文变化及洪水脉冲的周期性扰动,使得SW-GW转化的动力学过程促进了洪泛湿地环境系统之间物质、能量和信息的传递与交换,驱动了湿地演变、物质元素循环和生物生长等生态功能的实现。分析认为,洪泛湿地的开放性和复杂性等特点决定了多学科交叉理论与方法成为SW-GW转化研究的流行手段和创新的基本思路。从学科发展趋势和应用需求的角度出发,应结合洪泛湿地多源数据信息与SW-GW耦合数值模型,深入揭示洪泛湿地SW-GW转化的动力学过程及对洪水脉冲变化的响应机制,这既是一个基础性工作,也是一个具有前瞻性的研究,将为湿地水资源、水环境等综合管理与调控提供科学依据,对诠释湿地生态效应内涵具有重要意义。 相似文献
19.
GUO Lihe LIN Xingyuan Institute of Mineral Deposits CAGS Baiwanzhuang Beijing XIE Manze FENG Jialin Shijiazhuang Economic Institute Shijiazhuang Hebei WU Shuqi Institute of Rock Mineral Analysis Beijing 《《地质学报》英文版》1998,72(2):224-229
Minerals of various mantle-derived xenoliths from the Hannuoba basalt in Hebei Province have been studied by means of IR spectroscopy. The results show that all xenoliths from the mantle at depths <75 km contain trace amounts of water (0.45%-11.6×10-2 % H2O). The data of about 0.1% H2O contained in primary pyrolite estimated by earlier studies may be on the high side. The water might enter the frameworks of olivine, pyroxene and garnet earlier than it entered those of amphibole and phlogopite. The presence of water in amphibole and phlogopite may be a local phenomenon of water enrichment, which is related to relatively small-scale magmatic or metasomatic events although they can contain a hundred times more water than pyroxene contains. There is a little more water (1.11%-3.01×10-2 % of H2O mostly) in xenoliths from the Hannuoba basalt than in those from mid-ocean ridge basalt and kimberlites of South Africa (less than 1×10-2 % of H2O mostly). This indicates the heterogeneity of water in time and spa 相似文献
20.
浙闽泥质区是全新世高海平面以来沉积物的汇。受东亚季风影响,浙闽沿岸流和台湾暖流具有季节性变化,长江口"夏储冬输"的沉积物输运模式对东海内陆架泥质区的形成有关键作用。浙闽泥质区的潜在物源主要有长江、浙闽河流以及台湾西部山地河流,以长江物质为主。黏土矿物、稀土元素、Sr-Nd同位素、环境磁学等方法是物源研究的重要手段。长江物质以伊利石为主,蒙脱石含量较少,高岭石和绿泥石含量中等;而台湾物质以伊利石和绿泥石为主,没有蒙脱石。磁黄铁矿是台湾河流沉积物特有的磁性矿物,可作为大陆河流与台湾河流物源识别的指标。泥质区位于东亚季风区,受低纬热带过程和高纬大气环流的影响,气候变化具有波动性。沉积物敏感粒级反演的东亚冬季风（EAWM）只记录了泥质区形成以来的气候变化,不能代表整个全新世。受台湾暖流和浙闽沿岸流的双重影响,敏感粒级作为EAWM演化的指标需进一步深入研究。 相似文献