湘西北凤凰地区黑色岩系地球化学特征及地质意义

震旦系留茶坡组-寒武系牛蹄塘组在湘西北地区广泛分布,是重要的铀多金属富集层。文章通过微量元素分析与扫描电子显微镜相结合的技术手段,对凤凰地区黑色岩系微量元素与铀存在形式进行了分析,结果表明：Ni、Mo、V等多金属富集层位基本相同,且多与铀异常层重叠。V/(V+Ni)值为0.66～0.97,U/Th值为3.31～144.75,V/Sc值为28.62～4 155.05,V/Cr值为1.54～25.15,δU值为1.82～2.00,均指示缺氧-硫化环境;凤凰地区Ni-Co-Zn三角图解显示出热水沉积特征,稀土元素分析显示Eu正异常（δEu值为1.12～1.39）和Ce负异常（δCe值为0.32～0.77）,Sr/Ba值小于1,样品发育较多重晶石,结合微量元素特征与重晶石成因,认为沉积过程有海底喷流作用的参与。化学与生物化学作用使得铀多金属初步富集,海底喷流作用带来大量成矿物质,并对前期预富集的矿物溶蚀、萃取,在晶粒间或微裂隙重结晶,形成钛铀矿、紫硫镍矿和辉钼矿等独立矿物,同时在有机质作用下吸附各种多金属元素,形成钒系水云母矿物、硫钼矿集合体和针镍矿等多金属矿物（集合体）,最终固结成岩形成铀多...     

U-Th-Pb dating of garnet based on LAICP-MS mapping technology: A case study of the Tonglvshan large-scale Cu -Fe-Au skarn depositSCIEI北大核心CSCD

矽卡岩矿床的年代学信息对研究矽卡岩矿床的矿床成因、演变过程、成矿规律和找矿勘查具有重要的指示意义。石榴子石是矽卡岩矿床中的常见矿物,它具有一定的U含量,但是由于其普通铅高以及铀分布不均一的原因,导致激光剥蚀电感耦合等离子体质谱仪(LA-ICP-MS)点分析获得年龄成功率不高。针对点分析定年遇到的深度分馏和剥蚀点选取、普通铅校正等问题,本文提出一种利用LA-ICP-MS面扫描分析数据的虚拟点构建技术,在Tera-Wasserburg(TW)图中实现普通铅校正来确定含普通铅石榴子石年龄。通过理论推导、数值模拟和实验分析研究发现,利用相关联的^(208)Pb、^(232)Th、^(238)U测量数据校正生成^(208)Pb_(c)/^(238)U指标并据此对TW图中的数据进行数据分组抽样构造虚拟测量点,可以有效地把面扫描测量数据转换为与点分析测量类似但放射母子比例展布更优的数据。利用此方法对长江中下游成矿带鄂东矿区铜绿山大型Cu-Fe-Au矽卡岩矿床石榴子石进行面扫描分析。仅使用15min的样品面扫描数据,在获得了微量元素含量分布的同时,也获得了同位素比值虚拟点,交点年龄为139.2±2.9Ma(MSWD=0.7,n=126),与前人矿床研究结果相一致,验证了此方法的可行性。利用LA-ICP-MS面扫描定年技术不仅可以获得样品元素含量的二维分布图,有利于对样品期次的筛选,剔除包裹体等异常数据;还可以避免点分析中深度分馏和繁复的选点流程及二次分析等步骤,在获得样品元素含量分布的同时获得矿物年龄,为当前矽卡岩型矿床相关的关键金属研究提供了更为便捷的方法。     

Experimental study on the competitive adsorption of metal ions onto minerals

The study on the competitive adsorption shows that the magnitude order of metal ions adsorbed onto oxide and silicate minerals in near-neutral solution with low ionic strength is in mole/nm² as follows: CaCO₃ > quarte > hydromuscovite > kaolinite > Ca-montmorillonite > goethite > gibbsite. These minerals can be divided into three groups according to their surface equilibrium constantsK _M of the adsorption reactions, which are the function of the dielectric constants ε of the absorbent minerals. The relationships between constantsK _M and mineral dielectric constants ε are described as follows: lgK _M ¹ = 7.813-26.15/ε lgK _M ² = 9.030-26.15/ε lgK _M ³ =11.63-26.15/ε for the adsorption reaction: >SO^- + Mⁿ⁺≥SOM^n-1)+ (n = 1, 2, 3) The first group of minerals include quartz, goethite, 1:1 phyllosilicates and other oxide minerals; the second: gibbsite, brucite and 2:1 phyllosilicates; the third: carbonate, sulphate and phosphorate minerals. The appearance reaction constants have a variation of magnitude ±0.5 for different metal ions with the same mineral. This project was financially supported by the National Natural Science Foundation of China (No. 49572091).     

地理信息系统在金属矿产预测中的应用

地理信息系统ＧＩＳ是近几年发展起来的综合处理和分析空间数据的一种十分有效的新技术系统。利用ＧＩＳ可以对金属矿区现有大量的地学数据资料进行二次开发,进而成矿预测。本文利用ＧＩＳ（ＭａｐＶＧＩＳ）分析鄂东南地区铁矿成矿地质条件和找矿预测。     

氢化物发生-原子荧光光谱法测定多金属矿中的锡

多金属矿样品经酸溶解,Fe(OH)3共沉淀分离除去大部分Cu、Pb、Zn等干扰组分.含Sn沉淀经碱熔,水提取,氢氧化物进行二次沉淀分离,然后在酸性介质中,加入酒石酸-硫脲-抗坏血酸为掩蔽剂,用氢化物发生-原子荧光光谱法测定样品中的Sn量.方法检出限为0.20μg/g,样品中Sn的含量为7.47 μg/g和21.6 μg/g时,RSD(n=12)分别为6.5%和4.0%,加标回收率为88.6%～113.0%,经国家一级标准物质验证,结果与标准值相符.     

腾冲新歧碱长花岗岩稀有多金属风化壳矿床

新歧碱长花岗岩特富挥发分和成矿元素,多源补给充足。多期次、多阶段岩浆-热液活动,良好的活化、转移与聚矿地层介质环境,矿化岩体规模大,风化壳发育,可综合回收利用的矿化元素多,成矿远景及潜在经济价值较大。     

Using Multivariate Statistical and Geostatistical Methods to Identify Spatial Variability of Trace Elements in Agricultural Soils in Dongguan City,Guangdong,China

Dongguan (东莞) City, located in the Pearl River Delta, South China, is famous for its rapid industrialization in the past 30 years. A total of 90 topsoil samples have been collected from agricultural fields, including vegetable and orchard soils in the city, and eight heavy metals (As, Cu, Cd,Cr, Hg, Ni, Pb, and Zn) and other items (pH values and organic matter) have been analyzed, to evaluate the influence of anthropie activities on the environmental quality of agricultural soils and to identify the spatial distribution of trace elements and possible sources of trace elements. The elements Hg, Pb, and Cd have accumulated remarkably here, incomparison with the soil background content of elements in Guangdong (广东) Province. Pollution is more serious in the western plain and the central region, which are heavily distributed with industries and rivers. Multivariate and geostatistical methods have been applied to differentiate the influences of natural processes and human activities on the pollution of heavy metals in topsoils in the study area. The results of cluster analysis (CA) and factor analysis (FA) show that Ni, Cr, Cu, Zn, and As are grouped in factor F1,Pb in F2, and Cd and Hg in F3, respectively. The spatial pattern of the three factors may be well demonstrated by geostatistical analysis. It is shown that the first factor could be considered as a natural source controlled by parent rocks. The second factor could be referred to as "industrial and traffic pollution sources". The source of the third factor is mainly controlled by long-term anthropic activities ,ad a consequence of agricultural fossil fuel consumption and atmospheric deposition.     

非线性成矿预测理论:多重分形奇异性-广义自相似性-分形谱系模型与方法

介绍了“奇异性-广义自相似性-分形谱系”(“3S”: Singularity-generalized self-Similarity-fractal Spectrum)为核心的多重分形现代成矿预测理论与模型(Multifractal Mineralization Prediction Theory and Models)的基本内容和前沿研究方向.讨论了作为非线性、复杂性理论的重要领域之一, 多重分形理论所提供的“奇异性-广义自相似性-分形谱系”等概念和相关的模型.这些新概念和模型不仅能够合理地描述成矿系统、成矿过程、成矿富集规律、矿产资源时空分布, 还提供了定量模拟和识别成矿异常(地质、地球物理、地球化学、遥感异常)的有效模型和实用方法.将多重分形原理与成矿过程、矿产资源分布规律、矿产资源信息获取研究相结合, 可形成具有良好应用前景的现代成矿预测理论与模型.采用该多重分形矿产资源预测理论和在此基础上所开发的专用地学非线性空间信息GeoDASGIS技术, 对国内外多个金属成矿区带进行了矿产资源勘查与评价, 均取得了较理想的预测效果, 表明对开展矿产资源勘查和评价是有效和可行的.      

新世纪地球科学视野中的新技术和新方法

评价和区分大型矿床 ,一直是近年矿产勘查活动的焦点。最新研究表明 ,大型、巨型矿床与一般矿床的主要并可以量化的区别 ,在于大型、巨型矿床有着巨量的成矿元素供应与聚集。这种巨量的成矿元素供应 ,不是传统意义上元素的全量 ,而是能被成矿过程所利用的活动态分量。文中提出了基于元素立体分散模式和成矿可利用金属分量评价和区分矿床规模的一种定量地球化学模型和方法。