Integration of SPOT-5 and ASTER satellite data for structural tracing and hydrothermal alteration mineral mapping: implications for Cu–Au prospecting

ABSTRACT

The integration of information extracted from the Syste`m Pour l’Observation de la Terre (SPOT) and the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data, comprehensive field and mineralogy studies demonstrates that phyllic alteration zone associated with northwestern (NW)–southeastern (SE) structural fractures is a high potential zone for Cu–Fe–Au vein-type mineralisation in the Bajestan region, the Lut block, east Iran. The fractal pattern was calculated for fractures map using the Box-Counting algorithm to the SPOT-5 data. Statistical parameters of fractures, such as density, intensity and fractures’ intersection were also determined. Band composition, specialised band ratio and Spectral Angle Mapper (SAM) classification methods were implemented to the ASTER dataset for detecting hydrothermal alteration zones, such as propylitic, phyllic, argillic and gossan. Results indicate that the maximum value of the fractal dimension, intensity, density and the intersection of the fractures are concentrated in the NW and SE parts of SPOT image maps. In the other hand, phyllic alteration zone containing sericite, alunite, kaolinite and jarosite mineral assemblages was also identified in several zones of the NW and SE parts of the ASTER image maps. Integration of the results indicates the high potential zones for the occurrence of Cu–Fe–Au mineralisation in the Bajestan region.

KEYWORDS:

• SPOT-5
• ASTER
• hydrothermal alteration zones
• fractures map
• the Lut Block
• Iran

Acknowledgements

The present study is based on the first author`s PhD thesis at Ferdowsi University of Mashhad, Mashhad, Iran with the research number of 18300.3. We would like to express our great appreciation to Prof. Jixian Zhang and the anonymous reviewers for their very useful and constructive comments and suggestions for improvement of this manuscript. The authors gratefully acknowledge the Geological Survey of Iran (GSI) for its all supports. We offer special thanks to Dr Jafar Taheri the principal of GSINET (geological survey of Iran, North East Territory). We acknowledge the assistance of the Zamin Physic Pouya company for their logistic support during the field investigations and ground truth data collection. We also thank Korea Polar Research Institute (KOPRI) and University of Technology Sydney for their great assistance during preparation and revision the manuscript.