柴北缘成矿带矿化蚀变信息提取的方法研究

The method and practice on extracting of the mineralization alternation information with ETM image in the northern marginal mineralization belt of Chaidamu Basin

目的通过地物光谱测试及图像波谱分析,总结一套ETM卫星图像矿化蚀变信息提取的方法。方法根据野外波谱测试数据,建立蚀变矿物波谱数据库,并按ETM数据的波段对波谱库进行相应的重采样,使得重采样后的光谱分辨率与ETM的光谱分辨率相匹配,以选择矿化蚀变信息提取的最优波段组合;根据矿化蚀变信息提取的最优波段组合,分别采用比值(组合比值)、主成分分析(多重主成分分析)和光谱角填图等方法提取铁化、泥化和硅化信息,并对所提取的各类矿化蚀变信息进行可靠性评估。结果经野外实地验证和已知资料对比分析,预测的成矿远景区均具一定找矿前景。结论利用遥感技术手段,结合区域地质资料分析,在西部植被覆盖较少地区进行成矿远景预测是可行的。

Aim Using spectrum data collected on ground object and the image spectrum analysis, to generalize a set of working method on extract mineralization alternation from ETM satellite image. Methods According to spectrum data tested in the field establish spectrum database for the altered mineral, in order to carry on the corresponding sampling according to ETM data band, next cause the spectrum resolution of the sampling and the spect/um resolution of ETM bend matches, afterward choose the most superior wave band combination to extract the mineralization alternation information;According to the most superior band combination extract iron tincture and the pelization and the silicification information using the ratio separately （combination ratio）, the principal components analysis （multiple principal components analysis） and spectral angle mapping method. Moreover appraise reliability of these unusual information united geology and mineral and geochemistry. Results After field validation and comparison with the known data, the perspective area with mineralization we divided are all bearing bright prospect to find new mineral. Conclusion It is feasible to forecast the mineralized perspective area with remote sensing technical method combined with regional geology data analysis in the district with little vegetation such as northwestern part of China.