The Screening Of Ni-Cu-PGE Sulfide Ores Prospecting Target Area In Pan-xi Area In Si-chuan Province Based On "3S" Technology

PanZhihua-Xichang area, located in the southwest margin of the Yangtze platform, experienced several stages tectonic-magmatic activities and metamorphism, generating Cu, Ni-Cu-PGE and Fe-V-Ti complex metallogenic system and rich in minerals. Recently, with the rapid development of the mining industry and the consumption of the mineral resources, new metallogennic-prospecting theory and methods used in exploration are the key factors for finding out deposits in this area. Based on the "3S" technique, with the main lithogeochemical indicators, through the several relating research programes, we gain the innovation achievements and judgements:1. We firstly constructe 1: 200000 unified, standard database, including geology, mineral resources, geochemical exploration, remote sensing, gravity force and aeromagnetic data in PanZhihua-Xichang area.2. According to the comprephensive study of the 10 PGE-bearing intrusions in PanZhihua-Xichang area, absorbing the the foreign up-to-date theories and experimental information, the beginning of the restricted relation from partition coeficients for magma of PGE, the systematic analysing the Cu-Ni-PGE metallogenic material's transportation and concentration process, generalize the position of PGE reefs and lithogeochemical indicators in intrusions. We put forward to the conclution that there are six forms Cu-Ni-PGE mineralization, two important routes for PGE concentration(sulfide saturation) and three important indicator in looking for Ni-Cu-PGE sulfide deposits.Through the research of the six map sheets' regional original geochemistry data, involving Cu, Ni, Pt, Pd, Cr, Co, Fe, Ti and V elements, we discover that the high content of the Pt, Pd, Cu, Fe, Ni and V in stream sediments agrees with the distribution of the Emeishan basalts. And the high content of the Cr, Co and Ni are mainly controlled by the Emeishan basalts' west basalt district(Yanyuan basalt district) and the central basalt district(PanZhihua-Xichang basalt district). This new judgement provides us new awareness.4. Based on the fact that the geochemistry background is the discontinuous curved face in researching region, according to the systematic integration of the contrast technique in geochemical exploration, EDA(Exploratory Data Analysis) technique, data filtering technique, GIS and data interpolation technique, we creatively develop a method "subregion contrast filtered through outliers". The method effectively overcome the problems of the super-high background of the PGE, Cu, Ni in the Emeishan basalts area, and the lower background in the Precambrian system stratum. And we screened a series Cu, Ni, PGE's geochemical anomalies which can be further explored and appraised.5. Based on the principle of the similar analogy, we extract remote sensing information and geophysical information relating to mineralization.6. Supported by the MAPGIS, using Weights of Evidence Method and Expert Weight of Evidence, we predicte the targets of exploration programs of the copper deposit and Ni-Cu-PGE sulfide ores. And we screen Miesiluo etc several important prospecting target areas.