对数泛克立金法在处理化探数据中的应用

本文研究如何用地质统计学方法处理服从对数正态分布的化探数据的问题。经对湖北阳新岩体铜含量数据的大量电算、分析、对比,最后选用了对数泛克立金法。由计算机自动绘出的估值图和漂移、剩余图能很好地反映该区化探趋势和异常,既优于趋势面分析和滑动平均法,也优于泛克立金法,且能获得较稳健的变差图。故此法对化探数据自动成图很有用处。     

“三江”地区北段区域地球化学元素组合异常提取及其找矿意义

由于地球化学元素携带了某种矿化信息,因此元素地球化学异常往往是指示矿床存在的一种直接标志。随着勘查地球化学的深入发展,有关矿致地球化学异常圈定方法已成为人们关注的焦点。利用"三江"北段1∶20万地球化学数据,运用R型因子分析,查明该区不同矿化类型的指示元素组合,以因子得分为综合指标,采用泛克里格剩余值圈定地球化学异常。结果得到2种元素组合:Ag-Zn-Pb-Sb-Bi组合(与热液型铅锌银矿床有关)和Mo-Cu组合(与斑岩型钼矿床有关)。圈定的组合异常与已知的矿床点在空间上具有很好的对应关系,说明利用R型因子分析与泛克里格法相结合圈定元素组合异常的方法能够较好地确认地球化学元素组合异常,并提示异常与矿化类型之间密切相关的规律性,为"三江"北段地区找矿提供信息。     

区域化探扫面资料可以满足1:5万区调对化探的需求——试述水系沉积物测量采样密度试验成果

本文以福建区域化探的实际资料为基础,讨论了1:5万化探区调的采样密度.对比了不同采样密度的化深异常和经济效益.认为在福建省1:5万区域化探以1—2点/km²最好,既能取得较好结果,又经济高效.     

东天山中段区域化探异常评价方法研究

本文利用1/20万区域化探数据,研究了东天山中段地区针对不同类型铜矿化的元素组合异常圈定方法。选择典型（含）铜矿床及其周围地段的化探测量点为建模样本,通过因子分析,查明针对不同矿化类型的指示元素定量组合;以因子得分为综合指标,用泛克里格剩余值圈定化探异常。结果得到3个元素组合：Cu-Co-Ni-Mn-V-Fe-Cr组合...     

云南某地1:5万区调各种化探方法找矿经济效果对比

本文通过对云南西南部两个1:5万图幅地球化学水系沉积物测量、土壤测量和岩石测量三种区域化探方法的试验,从找矿、经济两个方面进行对比,得出了三种化探方法找矿效果相近的结论,但水系沉积物测量以其异常衬度高、野外采样工作量小、样品分析费用少而明显优于土壤测量。在试验中得到的另一发现是低密度(每平方公里约2个样)的岩石测量在发现异常信息和了解微量元素分布区域性变化规律方面有好的效果。岩石测量作为一种有效的区域化探方法值得重视和进一步研究。     

冀北步古沟一带萤石矿地物化找矿技术方法组合研究

地物化综合信息在热液充填型萤石矿找矿的应用探索具有重要意义。本文以冀北步古沟一带萤石找矿为例,通过综合物化探方法进行有效性试验,总结该地区萤石矿地物化找矿技术方法组合。在地质调查基础上,系统开展了1:5万水系沉积物地球化学测量、1:1万土壤剖面测量、高精度磁法测量、天然电场选频测量、电阻率联合剖面测量及高密度电阻率测量等找矿技术方法探索。结果表明,1:5万水系沉积物测量及1:1万土壤剖面测量等化探方法可辅助锁定找矿目标区;高精度磁法及天然电场选频测量,可初步判定断裂的位置;电阻率联合剖面及高密度电阻率法测量可进一步探测含矿断裂构造的位置、产状及延伸。通过以上试验研究,建立了冀北地区萤石矿地物化找矿技术方法组合,经工程验证在研究区内新发现萤石矿点1处,取得了较好的效果。实践表明,该套地物化找矿技术方法组合可进一步指导冀北地区的萤石矿找矿工作。     

云南省大理马厂箐-宾川小龙潭整装勘查区化探数据处理方法研究

化探是地质找矿的重要方法,在一定程度上决定着地质找矿的成败。本文通过对云南大理马厂箐-宾川小龙潭整装勘查区1:5万水系沉积物测量数据采用不同处理方法进行对比研究,得出比用传统的数据处理方法确定背景与异常,用衬值方法成图既能够达到地球化学图信息足够丰富并且能够较好的反映研究区的低缓异常,也能使较大的异常被拆分成若干小异常,使这些异常与已知的矿床（段）对应更好,以达到缩小靶区的目的,同时弱缓异常得到很好的增强,局部圈出若干个新异常,对实现找矿突破有一定的意义。     

Overview of a theory and method for prediction of mineral resources in China

A set of theories and methods has long been needed to enhance geological prospecting. Since 1982, we have been predicting mineral-resource potential based on geological research in China, using a comprehensive information theory and method (CIM), developed to identify mineral-resource domains. The key features of CIM are: (1) to establih comprehensive prospecting models on various scales on the basis of a metallogenic model; the prospecting models are statistical in nature and incorporate a range of ore indicators, (2) to compile detailed metallogenic maps that reflect metallogenic regularities, ore-controlling factors, prospecting indicators, and the positions of favorable target areas, and (3) to establish statistical prediction models of undiscovered mineral resources. This CIM method has been effective and has provided significant economic benefits in the past few years in China.     

藏东衣珠兴拉地区水系沉积物地球化学特征与找矿远景划分

西藏衣珠兴拉地区位于班公湖-怒江带东段,属于阿尔卑斯-喜马拉雅巨型系构造带向南转折的藏东三江地区,构造-岩浆活动强烈,具有良好的多金属矿成矿条件,是寻找铬铁、铅锌多金属矿的有利地区。依据1/5万水系沉积物测量成果研究表明:1)通过分析元素地球化学特征、元素相关性分析,认为Ag、Au、Cu、Pb、Zn、Sb等为本地区主要成矿元素;2)利用因子分析研究了元素组合特征及异常分布规律,结合成矿地质条件和已知矿床(点)信息,认为该区多金属矿化与燕山期岩浆热液成矿作用有关,具有明显的高中低温分带性;(3)划分出4处多金属矿成矿远景区,即拉桑卡-尼尼拉卡铬铁矿Ⅰ级成矿远景区、母拉同Ⅰ级成矿远景区、根达卡-曲功马Ⅱ级成矿远景区、摘龙-瓦昌达铅锌钨锡多金属成矿远景区Ⅱ级成矿远景区。     

粤北始兴鱼岔坑锡矿地球化学特征与找矿标志

刘家山地区是以寒武-奥陶系为赋矿层位的有色金属矿集区。通过1：20万水系沉积物测量，发现该区W，Sn，Pb，Zn等元素在粤北属低背景区。1：5万化探圈定的沟子坑异常属低背景高富集异常，为W，Sn，Bi，Cu，Pb，Zn，Ag，As异常组合；经化探详查和相关的地质工作发现了鱼岔坑锡（多金属）矿，矿化受层间破碎带控制，赋矿层位为奥陶系。该锡矿的化探找矿标志是低背景高富集异常，其组份复杂，浓集中心明显，且具分带性。     

岩石地球化学数据挖掘及弱异常识别--以新疆阿舍勒铜矿为例

勘查地球化学找矿工作的重点在于正确解译地球化学数据,以便从冗杂的地质信息中精准提取与成矿有关的异常信息,指导找矿研究。然而,地球化学数据属于成分数据,具有闭合效应,只有对数据进行正确的预处理才能应用多元统计分析方法,还原元素真实的空间分布。本文在阿舍勒铜锌矿区外围南侧区域共收集1009件地表原生晕样品,对样品中的13种微量元素进行测试,并对原始数据、对数及ilr变换后的数据进行EDA分析,对比数据空间分布及内部结构特征。运用(稳健)主成分分析,结合成分数据双标图及第一主成分点位图,解译三类数据指示的元素组合与成矿信息之间的关联。随后运用多重分形滤波技术,对以ilr变换为基础的稳健主成分得分数据分解元素组合异常和背景分布特征。结果表明:①经过对数及ilr变换后的数据相比原始数据空间尺度更均匀,数据近似正态分布;②三类数据双标图表明,仅ilr变换后的数据消除了“闭合效应”,且其第一主成分元素分组揭示了研究区铜矿化与铅锌多金属矿化组合;以对数变换与ilr变换为基础的第一主成分点位图表明,后者主成分得分异常能够较好指示研究区地质找矿信息;③结合研究区地质找矿信息、元素组合异常及背景空间分布特征,最终圈定3个有利找矿靶区。     

Gold prospecting methods in Yenisey range

Geophysical and geochemical exploration techniques are best adapted and extensively used in mapping and prospecting for gold within the Yenisey range. Results of high precisionaeromagnetic surveying (1:25,000), which has the advantage of being swift and inexpensive, are comparable with those of 1:50,000 surface magnetic surveying, with respect to the magnetic field detail. -- AGI Staff.     

甘肃阿克塞县变粒岩型铌钽矿综合找矿方法及找矿模型

甘肃阿克塞县余石山变粒岩型铌钽矿是近年在国内新区新层位发现的一种新类型铌钽矿床,其矿床规模已达大型,但对变粒岩型铌钽矿有效的综合找矿方法总结研究不够系统。本次依托1∶5万矿产地质调查和余石山铌钽矿普查等工作成果,系统梳理和分析总结了余石山铌钽矿的有效找矿方法,发现地质、地球化学、地球物理多学科综合找矿方法能快速准确定位铌钽矿带,总结了余石山铌钽矿表格式综合找矿模型,并提出了变粒岩型铌钽矿综合找矿方法组合：（1）优选熬油沟组地层分布区内的1∶5万水系沉积物测量Nb-Ta-La-Ce-Y组合异常和1∶5万地面高精磁测高磁异常的叠加区,确定为铌钽矿的找矿靶区;（2）在1∶5000岩石剖面测量和1∶2000高精磁测剖面浓缩物化探异常的同时,结合矿区大比例尺填图快速圈定铌钽矿带,推断隐伏-半隐伏矿带的有利部位;（3）槽探工程地表圈定矿体,深部钻探验证并寻找隐伏-半隐伏矿。     

陕南化探数据库的建设及开发应用

利用现代化计算工具及《区域地球化学数据管理系统》、MAPGIS地理信息系统等软件,对陕南地区57357km²历年来1:5万化探数据进行建库、数据处理及成图,提取有用信息,分析研究陕南地区区域地球化学特征及各元素富集规律。结合地质、物探资料及时指导找矿预测、资料二次开发及二轮找矿。     

Application of universal kriging for estimation of earthquake ground motion: Statistical significance of results

Universal kriging is compared with ordinary kriging for estimation of earthquake ground motion. Ordinary kriging is based on a stationary random function model; universal kriging is based on a nonstationary random function model representing first-order drift. Accuracy of universal kriging is compared with that for ordinary kriging; cross-validation is used as the basis for comparison. Hypothesis testing on these results shows that accuracy obtained using universal kriging is not significantly different from accuracy obtained using ordinary kriging. Tests based on normal distribution assumptions are applied to errors measured in the cross-validation procedure;t andF tests reveal no evidence to suggest universal and ordinary kriging are different for estimation of earthquake ground motion. Nonparametric hypothesis tests applied to these errors and jackknife statistics yield the same conclusion: universal and ordinary kriging are not significantly different for this application as determined by a cross-validation procedure. These results are based on application to four independent data sets (four different seismic events).     

冀北地区龙头山铅多金属矿床的发现及地物化综合找矿模型的建立

隐伏矿是当前矿产地质勘查的重点对象。在综合研究冀北地区1:20万区域示矿信息基础上,优选出锥子山花岗岩体一带的龙头山为找矿靶区,研究显示其具有较好的找矿潜力。1:5万水系沉积物地球化学测量圈定出11处综合异常;其中H6异常属于矿致异常。H6异常经1:1万地物化测量显示:Ag、Pb、Zn、Au等元素异常值高,具有外带—中带—内带三级分带;同时具有中低阻高极化的激电异常、蚀变矿（化）带与物化探异常相耦合的特征。通过进行系统地不同尺度地物化测量,缩小了找矿靶区,经工程验证发现了龙头山铅多金属矿床。矿体赋存在北西西向延伸、宽30~60 m的龙头山（F3）断裂构造系统中、产状较陡,赋矿围岩为太古界单塔子群（花岗）片麻岩和晚侏罗世张家口组安山岩,矿石多为细脉—浸染状、致密块状构造,矿床特征与毗邻的小扣花营、牛圈等多金属矿床类似,属于中低温热液脉型铅多金属矿床。最后,根据大比例尺地物化示矿信息特征,厘定了热液脉型铅多金属矿床的找矿标志,建立了地物化综合找矿模型,有利于推进冀北地区的找矿勘查。      

Application of geostatistics to identify gold-rich areas in the Finisterre-Fervenza region,NW Spain

Three univariate geostatistical methods of estimation are applied to a geochemical data set. The studied methods are: ordinary kriging (cross-validation), factorial kriging, and indicator kriging. These techniques use the probabilistic and spatial behaviour of geochemical variables, giving a tool for identifying potential anomalous areas to locate mineralization. Ordinary kriging is easy to apply and to interpret the results. It has the advantage of using the same experimental grid points for its estimates, and no additional grid points are needed. Factorial kriging decomposes the raw variable into as many components as there are identified structures in the variogram. This, however, is a complex method and its application is more difficult than that of ordinary or indicator kriging. The main advantages of indicator kriging are that data are used by their rank order, being more robust about outlier values, and that the presentation of results is simple. Nevertheless, indicator kriging is incapable of separating anomalous values and the high values from the background, which have a behaviour different to the anomaly. In this work, the results of the application of these 3 kriging methods to a set of mineral exploration data obtained from a geochemical survey carried out in NW Spain are presented. This area is characterised by the presence of Au mineral occurrences. The kriging methods were applied to As, considered as a pathfinder of Au in this area. Numerical treatment of Au is not applicable, because it presents most values equal to the detection limit, and a series of extreme values. The results of the application of ordinary kriging, factorial kriging and indicator kriging to As make possible the location of a series of rich values, sited along a N–S shear zone, considered a structure related to the presence of Au.     

综合找矿方法在山西小青沟银锰多金属矿田的应用

本文利用山西小青沟银锰多金属矿田的1：1万综合物化探测量资料,总结出激发极化法、高精度磁测、甚低频电磁法和化探原生晕是寻找该类型矿床的最佳综合找矿方法,并进行了有效的大比例尺成矿预测。     

FuzzyKrig: a comprehensive matlab toolbox for geostatistical estimation of imprecise information

Using kriging has been accepted today as the most common method of estimating spatial data in such different fields as the geosciences. To be able to apply kriging methods, it is necessary that the data and variogram model parameters be precise. To utilize the imprecise (fuzzy) data and parameters, use is made of fuzzy kriging methods. Although it has been 30 years since different fuzzy kriging algorithms were proposed, its use has not become as common as other kriging methods (ordinary, simple, log, universal, etc.); lack of a comprehensive software that can perform, based on different fuzzy kriging algorithms, the related calculations in a 3D space can be the main reason. This paper describes an open-source software toolbox (developed in Matlab) for running different algorithms proposed for fuzzy kriging. It also presents, besides a short presentation of the fuzzy kriging method and introduction of the functions provided by the FuzzyKrig toolbox, 3 cases of the software application under the conditions where: 1) data are hard and variogram model parameters are fuzzy, 2) data are fuzzy and variogram model parameters are hard, and 3) both data and variogram model parameters are fuzzy.     

镇沅县九甲金矿土壤地球化学特征及找矿前景

云南镇沅县九甲金矿区位于哀牢山成矿带.基于在矿区开展的1∶2.5万土壤地球化学测量,根据Cu、Au、As、Sb、Ag 5个元素的含量及分布特征,圈定了异常.结合矿区地层、构造、岩性等地质特征对土壤地球化学异常进行了综合评价,从中圈定了3个有找矿前景的综合异常,为矿区的找矿提供了有效的依据.