Hydrothermal alteration mapping for epithermal gold exploration at Rodalquilar with ASTER - Classic
This is a comprehensive exercise about the use of ASTER imagery, together with reflectance spectra and a hydrothermal alteration map, to map alteration centers related to epithermal metal deposits. The methods used in this exercise are simple but very effective. The first version of the exercise was made in the early 2000s and many versions have been prepared since.
It was originally developed for the advanced remote sensing course of the EREG MSC program at ITC. The version available here uses the ILWIS academic software and a spreadsheet. The resampling of ASTER imageres in the exercise is somewhat time-consuming.
The area can be found in Google Earth at approximately 35.5015 lat; -106.1750 lon.
• Instructions: Ex - Hydrothermal alteration mapping - instructions.pdf
• Data: Datastart.zip
• Answers to questions: Ex - Hydrothermal alteration mapping - answers to questions.pdf
• Slides with an overview of results: Ex - Hydrothermal alteration mapping - results.pdf
Compositional mapping for hydrocarbon exploration
This exercise shows how ASTER satellite imagery can be used to map differences in mineralogical composition that are related to an outcropping petroleum generating system. The compositional differences are enhanced by calculating band-ratios and shown in different colors. The image colors are related to and explained by a ternary (color) diagram. The band ratios highlight the occurrence of illite, evaporates and calcite.
The exercise was developed in 2015 as part of the Petroleum Geology master at the University of Dar es Salaam in Tanzania. The exercise was occasionally used in the image interpretation course of the AES MSc program at the faculty of ITC of the University of Twente in 2016 and 2017. A document with example answers to questions in the instructions and example screenshots of some of the results are available.
The area can be found in Google Earth at approximately 31.9970 lat; 49.3292 lon.
• Instructions: Ex - Compositional Mapping.pdf
• Data: ASTER satellite image: AST_L1B_32175_SWIR/VNIR; Folder with image spectra
• Example answers to questions: Ex - Compositional Mapping - ANSWERS.pdf
• Screenshots of selected results: Results.pdf