内蒙古朱拉扎嘎金矿区综合物化探方法在普查找矿中的作用

朱拉扎嘎金矿是内蒙古第一物化勘查院最新勘查成果,也是自五十年代开展物化探工作以来,应用综合物化探方法在内蒙古找到大型金矿床的典型案例。在内蒙古西部广大荒漠地区,这一综合物化探找矿方法可以推广使用。     

Regional geochemical surveys in arid and semiarid regions in the middle and western part of Inner Mongolia

For many years the results of regional geochemical surveys in arid and semiarid regions of China were not satisfactory. Therefore, we selected eight areas in the middle and western part of Inner Mongolia and the northwestern part of Gansu Province to study this problem from 1982 to 1985. The contents of our study include: the migration and distribution of elements in an arid environment; the interference of aeolian sand; the applicability of different sampling mediums; and the development of effective sampling techniques. Pilot surveys were carried out covering several hundred or more than a thousand square kilometres in every test area after the orientation study.Very good results were obtained in the surveys carried out in mountainous and hilly regions. The only problem was to eliminate effectively the interference of aeolian sand. To accomplish this we collected elastics of −5 + 2 mm or − 10 + 0.9 mm coarse grain size in the dry valley. In the stony Gobi desert region and the eroded peneplain region, a rock survey and residual soil survey produced the results expected. However, we had to consider the following influencing factors: (1) the caliche in the loose soil layer forms a barrier, hindering the migration of most of the elements in a vertical direction. Only where the caliche was rather thin was the influence of little significance; (2) in the residual soil of the background area and non-mineralized zone, almost all trace elements are enriched secondarily. The enrichment factors are generally between 1.3 and 1.8. In the residual soil of the mineralized zone, almost all ore-forming elements are impoverished. The well-water geochemical survey and the deep-root system plant survey have a peculiar function in finding ore deposits in the arid region. These two methods are discussed elsewhere.     

森林沼泽景观区区域化探新、旧方法技术应用效果对比

自森林沼泽景观区1∶20万区域化探工作开展以来,各个单位、不同阶段工作方法技术各有不同,工作效果不明显。中国地质科学院地球物理地球化学勘查研究所近年来通过研究制定了新的工作方法技术,通过应用取得了较好的效果,为此本文仅以内蒙古一二五公里幅1∶20万区域化探新、旧方法技术的应用效果对比进行初步探讨。     

近十年化探新方法新技术研究进展

本文简要介绍1987年以来地矿部物化探研究所在矿产勘查地球化学领域为寻找隐伏矿和提高其找矿效果而研究、开发的一些新方法、新技术。这里包括1:20万区域化探异常筛选与查证的方法技术,地气测量方法、金属活动态测量方法、价态金提取与测量方法、电提取方法及植物地球化学测量方法的新探索等。     

Distribution and formation of high-fluorine groundwater in China

In China, high-fluorine groundwater, which contains more than 1.0 mg/l fluorine, is mainly distributed in shallow aquifers of unconsolidated deposits in some arid and semiarid areas, deep aquifers of unconsolidated deposits in semiarid areas, as well as in hot springs of bed rock mountainous area and aquifers of fluorite-mine area. Its formation is controlled by regional climate factors, seepage conditions of groundwater, as well as the hydrogeochemical environment. The physicochemical properties of soil mass of the aeration zone play an important role in fluorine concentration in shallow groundwater. In the coastal plain areas, where groundwater is mainly recharged and discharged vertically, and its regime type belongs to the type of infiltration—evaporation, the grain size of soil mass of aeration zone directly influences the amount of fluorine transferred from solid medium into water; and the chemical constituents of the soil mass of aeration zone controls the chemical characteristics of the shallow groundwater, consequently influencing the concentration condition of fluorine in water. Fluorine ion in groundwater continuously migrates and concentrates under the comprehensive influence of many factors. High-fluorine groundwater exceeding the sanitary standard (1.0 mg/l) has an obvious zonality in regional distribution in China. Based on current statistics, there are roughly 50 million people (Zheng Qifu 1986) who have consumed water which exceeds standards in China. In highfluorine groundwater areas, endemic fluorine-poisoning often arises to different extents, affecting human health seriously. At the end of 1983, over 20 million patients were suffering from fluorine-poisoning diseases in China (Xu Guozhang, unpublished data). Therefore, research of the distribution feature and formation mechanism of fluorine ion in groundwater has become an important task.     

大地电磁测深(MTS)用于研究地壳上地幔的初步成果

地质矿产部物化探研究所自1980年先后完成了青藏、川滇、华南、甘肃、新疆、内蒙、山西、松辽、长江中下游、秦岭等地区的深大地电磁测深剖面约6800km。得出了剖面通过地区地壳、上地幔的电性结构,研究了各电性单元与地质构造单元的关系,对发现的地壳、上地幔内低阻层的成因进行了探讨。根据已掌握的深大地电磁数据编制了中国大陆电性图件,得出中国大陆岩石圈的平均厚度为100～120km,东部地区薄,西部地区厚的结论。利用高温高压岩石电阻率测定结果,粗略地给出了剖面通过地区岩石圈内主要的物质组成。     

干旱荒漠区综合物化探方法寻找铜多金属矿

为了研究在干旱荒漠区矿产检查工作中的有效物化探方法组合,实现地区找矿突破,以内蒙古黑鹰山地区某矿产检查调查区为例,探寻物化探方法寻找铜多金属矿的工作方法技术.调查区开展了1∶1万地质测量、大功率激电、高精度磁测及1∶5万热磁组分土壤测量面积工作.通过数据处理,圈定了2处激电异常和5处磁异常,区内也出现具有多元素组合异常特征的化探异常.在激电异常与元素异常浓集部位布置了可控源音频大地电磁测深剖面,确定了两个良导异常向下展布情况.探槽结果显示:在公婆泉组钠长阳起岩夹变质石英砂岩和大理岩接触处发生强烈硅化、矽卡岩化和孔雀石化;探槽样品中,多个样品中的Cu、Ag含量达到边界品位.区内找矿前景良好,可以开展进一步工作.     

鄂尔多斯浩勒报吉水源地开采地下水的环境影响分析

干旱半干旱区的地下水开发利用容易对原本脆弱的生态环境造成不利影响。内蒙古鄂尔多斯市浩勒报吉水源地属于半干旱区的地下水水源地。2009—2014年间,该水源地为满足工业供水需求开采地下水6.0×104~7.3×104 m3/d,产生了负面的生态环境后果。为核查环境变化与地下水开采的确切关系,调查分析了2004—2016年气象条件、地下水开采历程、地下水位、湖泊面积和植被指数的变化特征,建立定量指标进行了地下水开采的环境影响判别。结果表明,在2008—2014年期间,距开采区中心10 km范围的地下水位普遍下降1 m以上,奎生淖和敖各窖淖2个湖泊的面积萎缩约30%,水源地的植被指数对气候条件变化的敏感性增强。该水源地以往论证得到的可开采量偏大,应考虑生态环境约束将开采规模控制在3×104 m3/d以下。     

内蒙古中部地区太古宙绿岩带金矿找矿标志

内蒙中部地区金矿集中分布在太古界花岗岩──—绿岩带中，并受区域深大断裂带及韧性剪切变质带的控制，构成内蒙中部金的矿化集中区。尽管人们对金矿化的成因有不同认识，但找矿标志是有规律可寻的，因而，总结内蒙中部地区金矿化的找矿标志是有重要意义的。本文着重通过内蒙古中部区的含金建造、容矿构造、岩浆活动、载金矿物、围岩蚀变及地球物理、地球化学、遥感影象和重砂等方面，总结本区的金矿找矿标志。     

干旱-半干旱草原覆盖区地球化学找矿方法研究

在半干旱草原覆盖区,由于露头稀少、风成沙干扰明显,利用常规化探方法难以取得理想的找矿效果.以内蒙古新巴尔虎右旗为研究区,进行了土壤电导率测量和土壤元素活动态测量找矿方法试验研究.试验结果表明,在已知矿区,土壤电导率测量能明显反应下覆矿体的存在,土壤元素活动态含量在矿区和非矿区之间具有明显的差别.在未知区,土壤电导率测量获得3处异常,土壤元素活动态获得1处综合异常,所得各异常在对应位置均有不同程度的套合.通过2种方法在未知区的应用效果研究,土壤电导率测量和土壤元素活动态测量均能很好的圈出异常范围,浓集中心明显,并且土壤元素活动态测量具有进一步强化异常的作用.     

干旱荒漠区地下水中元素含量的季节性变化对水地球化学勘查的影响

本文描述了内蒙古某干旱荒漠区旱季和雨季期间地下地球化学异常的特征。根据19切们年旱季和雨季两次区域性地下水地球化学采样结果。发现地下水中主要指示元素含量具有明显的季节性变化。雨季期间水地球化学异常的峰值与旱季比较沿剖面向较低部位移动,已知矿带上方或其附近的主要指示元素的水地球化学异常几乎消失,异常的浓集中心向远离矿带处位移。文中详细探讨了本区降雨和蒸发一浓集作用对水地球化学异常的形成及运移的影响。     

内蒙干旱荒漠区域化探工作方法初步研究

内蒙和我国其它干旱荒漠区一样,由于:(1)风成沙干扰,使通常所选用的采样介质(土壤、水系沉积物)元素含量遭到稀释、歪曲,乃至样品间几乎没有差异；(2)缺乏一套针对干旱环境特点和该区地貌组合的特殊工作方法,致使区域性化探工作长期处于不利局面。     

甘肃省贵金属矿和铂族元素地球化学勘查的发展及新案例

由于Ａｕ、Ｐｔ、Ｐｄ等元素分析测试技术的突破，使中国的贵金属地球化学勘查得到迅速发展。甘肃省自８０年代以来，金矿地球化学勘查取得了丰硕的成果。９０年代初，在研究改进Ｐｔ、Ｐｄ、Ａｕ化学－光谱法快速联测分析方法的基础上，在祁连山地区开展了针对金和铂族元素的区域地球化学勘查。工作结果，Ｐｔ、Ｐｄ、Ａｕ的报出率都达到了１００％，从而可靠地圈定了Ｐｔ、Ｐｄ、Ａｕ的地球化学异常。这一案例证明，地球化学勘查在寻找金和铂族元素矿产方面都是有效的     

Recharge to the inter-dune lakes and Holocene climatic changes in the Badain Jaran Desert, western China

We present new estimates on evaporation and groundwater recharge in the Badain Jaran Desert, western Inner Mongolia of northwestern China, based on a modified Penman Equation suitable for lakes in China. Geochemical data and water balance calculations suggest that local rainfall makes a significant contribution to groundwater recharge and that past lake-level variations in this desert environment should reflect palaeoclimatic changes. The chronology of lake-level change, established by radiocarbon and U-series disequilibrium dating methods, indicates high lake levels and a wetter climate beginning at ca. 10 ka and lasting until the late mid-Holocene in the Badain Jaran Desert. The greatest extension of lakes in the inter-dune depressions indicates that the water availability was greatest during the mid-Holocene. Relicts of Neolithic tools and pottery of Qijia Culture (2400-1900 BC) suggest relatively intensive human activity in the Badain Jaran Desert during the early and middle Holocene, supporting our interpretation of a less harsh environment. Wetter climates during the Holocene were likely triggered by an intensified East Asian summer monsoon associated with strong insolation.     

重视内蒙古分散元素矿产资源的开发与利用

分散元素因其独特的地球化学性,多呈分散状态产于主金属矿物中,只有在特殊的地质条件下才能形成独立的分散元素矿床.分散元素具有重要与广泛的用途,是高科技新材料的重要原料,有着极其巨大的市场潜力.内蒙古与分散元素有关的金属矿床种类较多,资源储量丰富,可划分为3个分散元素富集区.对内蒙古的分散元素资源应加强选冶回收技术研究,积极推进资源勘查和开发利用工作.     

A Novel Approach in Hydrogeochemical Exploration for Uranium Mineralization: an Example from West Central Sinai, Egypt

Groundwater in contact with ore deposits may acquire a chemical composition that could be used as a guide for exploration. Eight well-water samples are collected from a known uranium-mineralized area near Abu Zenima, west central Sinai to examine the applicability of using the hydrogeochemical technique in the search for uranium mineralization in similar arid areas. The analytical chemical data of the ground water is compared with ground radiometric measurements. The obtained results indicate that groundwater affected by uranium mineralization has a specific relativity of major anions expressed essentially as SO4>Cl>HCO3 and to a lesser extent as Cl>SO4>HCO3, associated as a rule with low magnesium content. This association constitutes a signature of uranium mineralization on the composition of groundwater in west central Sinai and could be used as an important exploration guide in the search for uranium deposits in similar areas. Anomalies in Ni, Fe, Zn and Cr and other pathfinder elements in groundwater can furnish geochemical guides to uranium ores. The immobile trace element anomalies, including Zn, Ni and Fe are strongly distributed near the orebody; whereas the relatively mobile trace elements, including Co, U, V and Cr, constitute the dispersion haloes away from the orebody. A new hydrogeochemical discrimination diagram is constructed to be used as a quick and cost effective exploration tool in the search for uranium occurrences in environmentally similar arid areas. Based on the obtained results, a new site for uranium occurrence, west of W. Baba, is delineated and recommended for future detailed geological and geochemical surveying.     

内蒙古大型银矿集区地球化学预测

如何利用地球化学填图数据预测潜在大型矿集区是寻找大型矿床亟待解决的问题.本文利用1:20万区域化探扫面数据和1:100万中蒙边界地球化学填图数据进行综合研究,在全区共圈出面积大于1000km2银的地球化学省40个,其中具有良好Ag-Pb-Zn综合异常的有31处.内蒙已发现的4处大型银矿有3处位于地球化学省内,已发现的11处中型银矿有10处位于地球化学省或区域异常内,这说明大型银矿与地球化学省有高度的相关性.大型银矿区银异常强度(异常内银平均含量/背景含量)大于1.5.利用面金属量模型和地球化学块体模型对31处潜在的大型银矿区的潜在资源量进行了预测.     

Mapping of groundwater prospective zones integrating remote sensing,geographic information systems and geophysical techniques in El-Qaà Plain area,Egypt

The geospatial mapping of groundwater prospective zones is essential to support the needs of local inhabitants and agricultural activities in arid regions such as El-Qaà area, Sinai Peninsula, Egypt. The study aims to locate new wells that can serve to cope with water scarcity. The integration of remote sensing, geographic information systems (GIS) and geophysical techniques is a breakthrough for groundwater prospecting. Based on these techniques, several factors contributing to groundwater potential in El-Qaà Plain were determined. Geophysical data were supported by information derived from a digital elevation model, and from geologic, geomorphologic and hydrologic data, to reveal the promising sites. All the spatial data that represent the contributing factors were integrated and analyzed in a GIS framework to develop a groundwater prospective model. An appropriate weightage was specified to each factor based on its relative contribution towards groundwater potential, and the resulting map delineates the study area into five classes, from very poor to very good potential. The very good potential zones are located in the Quaternary deposits, with flat to gentle topography, dense lineaments and structurally controlled drainage channels. The groundwater potential map was tested against the distribution of groundwater wells and cultivated land. The integrated methodology provides a powerful tool to design a suitable groundwater management plan in arid regions.     

Hydrogeochemical characterization and quality assessment of groundwater using self-organizing maps in the Hangjinqi gasfield area,Ordos Basin,NW China

Water resources are scarce in arid or semiarid areas,which not only limits economic development,but also threatens the survival of mankind.The local communities around the Hangjinqi gasfield depend on groundwater sources for water supply.A clear understanding of the groundwater hydrogeochemical characteristics and the groundwater quality and its seasonal cycle is invaluable and indispensable for groundwater protection and management.In this study,self-organizing maps were used in combination with the quantization and topographic errors and K-means clustering method to investigate groundwater chemistry datasets.The Piper and Gibbs diagrams and saturation index were systematically applied to investigate the hydrogeochemical characteristics of groundwater from both rainy and dry seasons.Further,the entropy-weighted theory was used to characterize groundwater quality and assess its seasonal variability and suitability for drinking purposes.Our hydrochemical groundwater dataset,consisting of 10 parameters measured during both dry and rainy seasons,was classified into 6 clusters,and the Piper diagram revealed three hydrochemical facies:Cl-Na type(clusters 1,2 and 3),mixed type(clusters 4 and 5),and HCO3-Ca type(cluster 6).The Gibbs diagram and saturation index suggested thatweathering of rock-forming mineralswere the primary process controlling groundwater chemical composition and validated the credibility and practicality of the clustering results.Two-thirds of 45 groundwater samples were categorized as excellent-or good-quality and were suitable as drinking water.Cluster changes within the same and different clusters from the dry season to the rainy season were detected in approximately 78%of the collected samples.The main factors affecting the groundwater quality were hydrogeochemical characteristics,and dry season groundwater quality was better than rainy season groundwater quality.Based on this work,such results can be used to investigate the seasonal variation of hydrogeochemical characteristics and assess water quality accurately in the others similar area.     

Groundwater–wetlands interaction in coastal lagoon of Almería (SE Spain)

Water resources management in coastal wetlands requires the degree of interdependence between groundwater and terrestrial ecosystems to be known. This is especially so in semiarid areas where surface inflows are restricted, marine influence is marked and the evaporation rate is high. Thus, chemistry of surface waters is very variable in the Cerrillos-Punta Entinas wetlands system. Using classical hydrogeochemical tools, the main processes that favor a diversity of water types were described, related to: presence of salt deposits on the lagoon beds, marine origin of the water, and local influence of groundwater. All these factors make it difficult to establish what reference conditions should be used to define “good” water quality of the surface waters—as required by the Water framework directive—and to understand the influence of groundwater on these coastal wetlands. Knowledge about the influence of the different interaction of these factors on the hydrogeochemical dynamics is required for the sustainable management of this protected natural site.