区域岩溶水水化学特征与渗流研究

通过对川西南某水电工程坝址上、下游几十公里范围内下二叠统（Ｐ１）地层中岩溶水水化学场特征的分析研究和对比,运用反证法判定,区内该层中的岩溶水,虽然处在同一个含水系统中,但并非属同一个流动系统,进而论证了在不蓄水情况下不存在库区、坝区地下水沿Ｐ１灰岩向金沙江下游渗流问题。结果显示,利用水化学成分信息判定坝址上、下游岩溶水是否属同一个流动系统,进而分析渗漏可能性是一种简单、可靠的方法。     

Bayesian and multivariate methods applied to favorability quantification in Recôncavo Basin and Ribeira Belt, Brazil

A methology to define favorable areas in petroleum and mineral exploration is applied, which consists in weighting the exploratory variables, in order to characterize their importance as exploration guides. The exploration data are spatially integrated in the selected area to establish the association between variables and deposits, and the relationships among distribution, topology, and indicator pattern of all variables. Two methods of statistical analysis were compared. The first one is the Weights of Evidence Modeling, a conditional probability approach (Agterberg, 1989a), and the second one is the Principal Components Analysis (Pan, 1993). In the conditional method, the favorability estimation is based on the probability of deposit and variable joint occurrence, with the weights being defined as natural logarithms of likelihood ratios. In the multivariate analysis, the cells which contain deposits are selected as control cells and the weights are determined by eigendecomposition, being represented by the coefficients of the eigenvector related to the system’s largest eigenvalue. The two techniques of weighting and complementary procedures were tested on two case studies: 1. Recôncavo Basin, Northeast Brazil (for Petroleum) and 2. Itaiacoca Formation of Ribeira Belt, Southeast Brazil (for Pb-Zn Mississippi Valley Type deposits). The applied methdology proved to be easy to use and of great assistance to predict the favorability in large areas, particularly in the initial phase of exploration programs.     

吉南玄武岩覆盖区水化学异常查证──以两处金矿化的发现为例

本文通过实例,介绍了吉南玄武岩覆盖区水化学异常查证的化探工作方法。综合研究已有地质条件,认为吉南沿江村、马鹿沟水化学异常地区成矿地质条件有利。结合微景观特点,在沿江异常区2km²范围内应用汞气测量圈出区内断裂构造带展布方向。岩石剖面、土壤测量显示出构造经历过热液矿化活动,矿化体埋藏较深。根据土壤测量结果优选出验证靶区。钻探验证结果在地表620m以下发现了近30m厚的Au矿化体,Au含量最高1.5g/t.马鹿沟水化学异常区使用水系沉积物测量进行异常追踪,迅速缩小了找矿“靶区”.使用重矿物测量在“靶区”内进一步追踪发现了Au矿化源。在此基础上经大比例尺土壤测量辅以岩石剖面测量,圈出了一个有望找到火山岩型浅成热液金矿床的成矿远景区。     

根据综合物探信息初探鄂东南地区的深部找矿问题

本文根据鄂东南地区的成矿规律和矿床特征,着重讨论了几个已知矿区深部矿体与综合物探信息之间的关系;通过部分野外工作和大量的计算,对区内阳新岩体西北端进行了深部成矿预测;并指出了在深部找矿过程中应注意的几个问题。     

水化学特征在岩溶水系统分析中的应用——以山西晋城长河流域岩溶水系统为例

通过对长河流域岩溶水矿化度、Ca^2＋／Mg^2＋、Ca／Sr及Mg／Sr等的特征分析,长河流域岩溶水系统从补给区到径流区、排泄区矿化度、Can／Mgn、Ca／Sr及Mg／Sr变化具有明显的规律性,岩溶水的流动方向则与以上各水化学指标质量浓度的变化方向一致,即研究区在东、北部灰岩裸露区直接接受大气降雨补给渗漏及部分半裸露区间接补给渗漏,向西以泉水形式排泄到沁河河谷地带,形成沁河河谷排泄带,地下水径流方向为南西西方向。并分析岩溶地下水的径流特征,富水强弱,水岩作用强弱及岩溶裂隙发育规律特征。     

慕士塔格山卡尔塔马克冰川补给径流与非冰川补给径流水化学特征及主控因素研究

2016年7~8月对慕士塔格山卡尔塔马克冰川补给径流与非冰川补给径流进行了采样分析,通过统计分析、主成分分析、Piper图、Gibbs图、正演模型等方法分析了冰川补给径流和非冰川补给径流的水化学特征及其主控因素。结果表明：冰川补给径流和非冰川补给径流两种水体均呈碱性,水化学类型皆为Ca²⁺-SO₄^2--HCO₃^-,但冰川补给径流和非冰川补给径流的pH值、EC和TDS均存在显著差异（p<0.05）,主要离子浓度间均存在极显著差异（p<0.01）。冰川补给径流中所有离子具有同源性,而非冰川补给径流NO₃^-显示出与其它离子来源不同。正演模型结果显示,大气输入、硅酸盐风化、碳酸盐风化和蒸发岩溶解对冰川补给径流和非冰川补给径流中离子浓度的贡献率分别为10.47%、0.55%、65.61%、23.37%和1.52%、19.57%、60.37%、18.54%。在冰川补给径流中,碳酸盐风化对径流中离子浓度的贡献占主导地位,蒸发岩溶解占次要地位;在非冰川补给径流中,碳酸盐风化亦占主要支配地位,而硅酸盐风化占次要地位。两者差异的原因是硅酸盐风化相比蒸发岩溶解更难进行,冰川补给径流中水岩相互作用时间较短,故硅酸盐风化贡献率较低;而非冰川补给径流经过更充分的水岩相互作用,故硅酸盐风化贡献率较高。其成果可为西部地区水资源管理应用提供参考。     

Hydrochemistry and H-O-C-S Isotopic Geochemistry Characteristics of Geothermal Water in Nyemo-Nagqu, Tibet

Nyemo-Nagqu, Tibet, is rich in high-temperature geothermal resources. The geothermal fields in Yangbajain and Yangyi as well as 11 unexplored geothermal fields along the geothermal belt from Nyemo to Nagqu were systematically investigated and the hydrochemistry data were collected from the whole field. Meanwhile, H-O-C-S isotope data were obtained for the new fields, and H-O isotope data for the Yangbajain and Yangyi fields. A comparison of the Nyemo-Nagqu geothermal fields with those in the Yangbajain area shows that the types of high-temperature geothermal water are dominated by Cl-Na and Cl·HCO_3-Na, while the types of medium-high-temperature geothermal water are dominated by HCO_3-Na. The concentrations of Li, F, SiO_2, and HBO_2 in the geothermal water are positively correlated with Cl content, indicating possible mixing with magma water. The reservoir temperatures range from 90 to 270°C by geothermometers. Slight drifting of ~(18)O was recorded at the Dongweng and Nyingzhong high-temperature geothermal fields, while more significant drifting was recorded at Gulu. The geothermal water is mainly replenished by atmospheric precipitation. The low tritium contents(1 TU) of the geothermal water from Nyingzhong, Gulu, and Luoma indicate that it is mainly replenished by sub-modern(prior to 1952) water, while the high tritium content(8.4 TU) in Yuela implies modern water replenishment. Other geothermal fields are replenished by a mix of sub-modern fresher water. The isotopic data in this study show that the carbon and sulfur in the geothermal water originates mainly from sediment leaching, with some of the carbon and sulfur having a deep origin.     

The chemical composition of the surface system of Peneos river, Thessaly/Central Greece

 Peneos is the mainstream for the drainage of Thessaly's basin. It contributes significantly in recharging the aquifers, as well as to the direct irrigation water, since there is intense agricultural activity in the basin of Thessaly. The investigation of the hydrochemical conditions of the surface water system of Peneos showed that the chemical composition is related to the lithology of the aquifers of the basin, the anthropogenic influence and the biological activity. The chemical composition of this system changes in time and space. The salinity decreases during the winter period, in contrast to the summer period when it increases drastically. The lower values of TDS appear in the upstream part of the river (95–124 mg/l) whereas downstream, the values of TDS increase significantly (400–632 mg/l). The hydrochemical type Ca-Mg-HCO₃ dominates the largest part of the river while it changes to NA-Cl in the estuary. The concentrations of the dissolved species in the main Peneos river are higher than in the spring waters. Peneos is the most polluted river in Greece. The concentration of the pollutants is higher at the downstream part of the river, but is lower than the accepted upper limits. The use of the surface water of the system of Peneos river for irrigation purposes based on the SAR factor is acceptable because the absorption ratio for Na and salinity are low and medium respectively. Received: 27 October 1997 · Accepted: 21 September 1998     

青藏高原西部、南部和东北部边界地区天然水的水化学性质及其成因

特殊的地理和人文环境致使青藏高原天然水拥有独特的水化学性质并保存着较完整的原生状态,但随着人类活动强度的持续增大,可能导致当地水环境及水化学性质发生改变。通过对青藏高原存在人类活动的西部、南部和东北部边界地区进行水样采集、分析与测定,并探讨了当地天然水水化学性质的区域差异及其成因规律。结果表明:青藏高原不同边界地区天然水的物理性质、水化学性质和成因均存在差异,这些差异主要是地理环境、地质条件等综合作用的结果;水样pH的平均值为7.75,总溶解固体(TDS)的均值为171 mg/L,总硬度(TH)的均值为168 mg/L,总体来看水质较好,大部分能够满足国家和世界卫生组织(WHO)生活饮用水卫生标准,适宜饮用;水样中Ca²⁺和Mg²⁺为主要阳离子,HCO_3^-和SO_4^2-为主要的阴离子,主要由碳酸盐的风化和蒸发岩的溶解共同控制且碳酸盐岩风化的过程更为强烈;各边界地区天然水中的生物源物质均远低于国家和WHO标准,表明目前这些地区受人类活动的影响仍较小。     

Hydrochemical characteristics and controlling factors of natural water in the border areas of the Qinghai-Tibet Plateau

Journal of Geographical Sciences - The special geography and human environment of the Qinghai-Tibet Plateau has created the unique hydrochemical characteristics of the region’s natural water,...