Application Of Bi-dimensional Empirical Mode Decomposition(BEMD) And Singular-Value Decomposition(SVD) In Extraction Of Pt-Pd-Cu Anomalies In Eastern Yunnan Province, Southwestern China

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.