TITLE:
Lithological Analysis of Nain Ophiolitic Zone Using ASTER Data
AUTHORS:
Ali Reza Nasiri Khaneghah, Ramin Arfania
KEYWORDS:
Ophiolitic Mélange, Ultramafic Rocks, Advanced Space Borne Thermal Emission and Reflection Radiometer (ASTER), Optimum Index Factor (OIF), Feature Oriented Principal Components Selection (FPCS), Band Ratio (BR)
JOURNAL NAME:
Open Journal of Geology,
Vol.7 No.8,
August
23,
2017
ABSTRACT: The Mesozoic ophiolitic Mélange, north of Nain in the Central-East Iran Microplate (CEIM) comprises serpentinized ultramafic rocks, harzburgites, dunite, gabbro, peridotite, pelagic limestone and other carbonate rocks. The excellent and vast exposure of this desert region is well suited for geologic mapping of this rock suite using remote sensing, especially using data from the satellite-borne advanced Space borne Thermal Emission and Reflection Radiometer (ASTER) imaging system which was designed for mapping mineral information. In this study, data processing methods like Method Minimum noise fraction (MNF), Feature Oriented Principal Components Selection (FPCS), Band Ratios (BR) and Optimum Index Factor (OIF) were used to process ASTER data to optimize the mapping of ophiolite rock types. For example, a simple color composites of OIF (Red: B3, Green: B4, and Blue: B8) and Band ratios (e.g. Red: (B2 + B4)/B3, Green: (B5 + B7)/B6, Blue: (B7 + B9)/B8) were useful for discriminating serpentinite, meta-basalt and granite rock types. It is concluded here that proposed ASTER data has the potential for mapping similar ophiolites elsewhere using the global archive of ASTER imagery.