Application of multifractal modeling for the identification of alteration zones and major faults based on ETM+ multispectral data

摘要

The aim of this study is to investigate the reconnaissance of alteration zones and faults in Hashtjin 1: 100,000 sheet (NW Iran) using concentration-area (C-A) fractal model based on remote sensing data, which has been extracted from enhanced thematic mapper (ETM)+ multispectral images. There are Oligocene volcano-plutonic rocks and Tarom-Hashtjin metallogenic zone with Cu, Au, and Pb-Zn occurrences in the studied area. The concentration-area (C-A) fractal model proposed in this paper for the interpretation of pixel value distribution spatial patterns based on the extracted data from ETM+ multispectral images. The pixel values were calculated by the PCA (principal component analysis) method for iron oxides and argillic alteration. Furthermore, the sharpen-filtering has been applied to calculate the value pixels for the main fault zone in the Hashtjin area. The C-A model can be used to establish power-law relationships between the area and the pixel value. The log-log C-A plots show multifractal nature for iron oxides, argillic alteration zones, and faults. Results obtained by the fractal model reveal that alteration zones and major faults have a NNW-SSE trend. The alteration zones and major faults have a strong correlation with the geological map of the area.