Alteration is regarded as significant information for mineral exploration. In this study, ETM＋ remote sensing data are used for recognizing and extracting alteration zones in northwestern Yunnan （云南）, China. The ...Alteration is regarded as significant information for mineral exploration. In this study, ETM＋ remote sensing data are used for recognizing and extracting alteration zones in northwestern Yunnan （云南）, China. The principal component analysis （PCA） of ETM＋ bands 1, 4, 5, and 7 was employed for OH alteration extractions. The PCA of ETM＋ bands 1, 3, 4, and 5 was used for extracting Fe^2＋ （Fe^3＋） alterations. Interfering factors, such as vegetation, snow, and shadows, were masked. Alteration components were defined in the principal components （PCs） by the contributions of their diagnostic spectral bands. The zones of alteration identified from remote sensing were analyzed in detail along with geological surveys and field verification. The results show that the OH^- alteration is a main indicator of K-feldspar, phyllic, and prophilized alterations. These alterations are closely related to porphyry copper deposits. The Fe^2＋ （Fe^3＋） alteration indicates pyritization, which is mainly related to hydrothermal or skarn type polymetallic deposits.展开更多
Satellite remote sensing data are usually used to analyze the spatial distribution pattern of geological structures and generally serve as a significant means for the identification of alteration zones. Based on the L...Satellite remote sensing data are usually used to analyze the spatial distribution pattern of geological structures and generally serve as a significant means for the identification of alteration zones. Based on the Landsat Enhanced Thematic Mapper （ETM＋） data, which have better spectral resolution （8 bands） and spatial resolution （15 m in PAN band）, the synthesis processing techniques were presented to fulfill alteration information extraction： data preparation, vegetation indices and band ratios, and expert classifier-based classification. These techniques have been implemented in the MapGIS-RSP software （version 1.0）, developed by the Wuhan Zondy Cyber Technology Co., Ltd, China. In the study area application of extracting alteration information in the Zhaoyuan （招远） gold mines, Shandong （山东） Province, China, several hydorthermally altered zones （included two new sites） were found after satellite imagery interpretation coupled with field surveys. It is concluded that these synthesis processing techniques are useful approaches and are applicable to a wide range of gold-mineralized alteration information extraction.展开更多
基金supported by the project "Remote Sensing Alteration Abnormity Extraction from Geological Survey in Northwestern Yunnan, China" from China Geological Survey
文摘Alteration is regarded as significant information for mineral exploration. In this study, ETM＋ remote sensing data are used for recognizing and extracting alteration zones in northwestern Yunnan （云南）, China. The principal component analysis （PCA） of ETM＋ bands 1, 4, 5, and 7 was employed for OH alteration extractions. The PCA of ETM＋ bands 1, 3, 4, and 5 was used for extracting Fe^2＋ （Fe^3＋） alterations. Interfering factors, such as vegetation, snow, and shadows, were masked. Alteration components were defined in the principal components （PCs） by the contributions of their diagnostic spectral bands. The zones of alteration identified from remote sensing were analyzed in detail along with geological surveys and field verification. The results show that the OH^- alteration is a main indicator of K-feldspar, phyllic, and prophilized alterations. These alterations are closely related to porphyry copper deposits. The Fe^2＋ （Fe^3＋） alteration indicates pyritization, which is mainly related to hydrothermal or skarn type polymetallic deposits.
基金The paper is supported by the Research Foundation for Out-standing Young Teachers, China University of Geosciences (Wuhan) (Nos. CUGQNL0628, CUGQNL0640)the National High-Tech Research and Development Program (863 Program) (No. 2001AA135170)the Postdoctoral Foundation of the Shandong Zhaojin Group Co. (No. 20050262120)
文摘Satellite remote sensing data are usually used to analyze the spatial distribution pattern of geological structures and generally serve as a significant means for the identification of alteration zones. Based on the Landsat Enhanced Thematic Mapper （ETM＋） data, which have better spectral resolution （8 bands） and spatial resolution （15 m in PAN band）, the synthesis processing techniques were presented to fulfill alteration information extraction： data preparation, vegetation indices and band ratios, and expert classifier-based classification. These techniques have been implemented in the MapGIS-RSP software （version 1.0）, developed by the Wuhan Zondy Cyber Technology Co., Ltd, China. In the study area application of extracting alteration information in the Zhaoyuan （招远） gold mines, Shandong （山东） Province, China, several hydorthermally altered zones （included two new sites） were found after satellite imagery interpretation coupled with field surveys. It is concluded that these synthesis processing techniques are useful approaches and are applicable to a wide range of gold-mineralized alteration information extraction.
