【作者】 菅贞贞；

【导师】 陈永清；

【作者基本信息】 中国地质大学(北京) ， 地球探测与信息技术， 2012， 硕士

【摘要】 地球化学元素异常的提取一直是勘查地球化学家最重要的工作之一，但迄今还没找到一个完全令人满意的具有科学依据的方法。长期经来，人们主要使用经典的统计学方法：均值与两倍的标准离差之和（(?)+2S）作为异常下限对全部数据进行异常筛选和评价，该方法难以客观地描述成矿元素含量变量的空间分布规律，并不能很好的应用于处理非线性和非平稳数据。“非线性”和“复杂性”科学能够深刻揭示自然复杂系统中固有的内在本质规律，是21世纪自然科学的重要前缘研究领域之一。本研究选用由云南地调院提供的滇东地区化探组合副样，针对地球化学元素的随机性、非线性和非平稳性特征，分别将二维经验模分解（BEMD）和奇异值分解（SVD）的理论与方法应用于滇东地区的Pt、Pd、Cu含量数据的异常信息提取中，并将两种方法的结果进行了进一步的对比研究，最终结合滇东地区的地质背景和成矿特征，得出具有一定矿产资源潜力的找矿有利地段和成矿远景区，为地球化学勘查的研究提供了新方法。研究成果如下：1.二维经验模分解（BEMD）与奇异值分解（SVD）方法原理虽不同，但都有根据自身定义的低通、带通和高通滤波器滤波功能。通过各自定义的滤波器获得明显的Pt、Pd、Cu致矿异常信息，获取了两类刻画不同尺度的元素异常图：区域Pt、Pd、Cu异常和局部Pt、Pd、Cu异常。2.根据异常产出的地质特征，区域Pt、Pd、Cu异常可进一步划分为2种亚类：其一是位于受SN向小江断裂和NE向寻甸—宣威深大断裂控制的二叠纪峨眉山玄武岩分布区的异常，其特征是具有明显的浓集中心，异常强度大；其二是分布于研究区中南部的黑色岩系中的异常，异常强度弱。其中前者是滇东Pt、Pd、Cu找矿的有利地段。局部Pt、Pd、Cu异常可进一步划分为：⑴分布于玄武岩区，受SN-NE向深大断裂与其次级断裂交汇域控制的异常；⑵分布于不同地质时期黑色岩系中的异常；其中，分布于玄武岩区的Pt、Pd、Cu局部异常强度高，规模大，是进一步找寻Pt、Pd、Cu资源的远景地段。更多还原

【Abstract】 Extracting abnormal of geochemical elements has always been considered as one of the mostimportant work for exploration geochemistry, but until now there is no satisfied scientificmethod completely. The Classical statistical, adding two times standard deviation to mean（（?）+2S）, was used as the anomaly threshold to extract and evaluate abnormal for a long time.But it can not deal with nonlinear and non-stationary data very well. And it is difficult toobjectively describe spatial distribution of the content of ore-forming elements.Nonlinearity and complexity are important research fields of natural science in the21stcentury, which can deeply reveal the internal essential rule in natural complex system. This studyselect geochemical samples in Eastern Yunnan province, Southwestern China provided byYunnan Geological Survey Institute and apply bi-dimensional empirical modedecomposition（BEMD） and singular-value decomposition（SVD） to analyze random, nonlinearand non-stationary Pt, Pd and Cu concentration data. Finally, the results of both methods will befurther researched. With the geological background and metallogenic characteristics of researcharea, we delimit preferable ore-finding areas and prospective ore-forming areas in eastern Yunan.It provides a new method for geochemical exploration research. The results are shown asfollows,1. The principle of bi-dimensional empirical mode decomposition（BEMD） and singular-valuedecomposition（SVD） are different, but they have high-pass S_HP（x, y）, band-pass S_BP（x, y） andlow-pass S_LP（x, y） filters according to their own characters. Through the filters, obvious Pt, Pdand Cu anomaly information were extracted, and two kinds of element anomalies in differentscales are obtained: the regional and local Pt、Pd and Cu anomalies.2. The regional Pt、Pd and Cu anomalies can be subdivided into two categories based ongeological features of anomalies occurrence. One is those with obvious concentrated centers andhigh anomalous intensity which is located at Emeishan basalt areas controlled by the SN trend ofthe Xiaojiang fault and the NE trend of the Xundian-Xuanwei fault. The other is those with weakanomalous intensity which is distributed in black rock series of central and southern parts of thestudy area. The former is the favorable areas for prospecting Pt、Pd and Cu deposits. The localPt、Pd and Cu anomalies also can be subdivided into two sub-categories: one is those which arelocated at the Emeishan basalts controlled by the intersecting areas of both the SN and the NEtrend of deep-seated faults and their secondary faults; the second is those which are located inblack rock series with different geologic epoch. The first one with high strength of Pt-Pdanomalies are prospective areas for Pt、Pd and Cu deposits.更多还原