Discrimination between Sedimentary Rocks from Close-Range Visible and Very-Near-Infrared Images

Area of Science:

• Geoscience
• Remote Sensing
• Mineralogy

Background:

• Mineral composition variations in rocks alter their spectral response, enabling study via imaging spectroscopy.
• Multispectral imaging offers a non-invasive method for geological material characterization.

Purpose of the Study:

• To evaluate the potential of a low-cost, calibrated visible-very near infrared (VIS-VNIR) multispectral camera for geological formation recognition.
• To assess the camera's capability for discriminating between rock types and for close-range mapping applications.

Main Methods:

• Spectral data acquisition using a Tetracam Mini-MCA-6 camera (six bands, 0.530–0.801 µm) on a field platform.
• Selection of twelve sedimentary formations in the Rhône-Alpes region, France.
• Supervised classification (maximum-likelihood) of processed multispectral data to distinguish limestones, marlstones, vegetation, and shadows.

Main Results:

• The calibrated VIS-VNIR multispectral camera demonstrated significant potential for geological discrimination.
• Successful differentiation between limestone and marlstone lithologies was achieved.
• The camera proved efficient for mapping limestone-marlstone alternations in geological formations.

Conclusions:

• A low-cost VIS-VNIR multispectral camera is a viable tool for geological mapping and mineral composition analysis.
• This technology facilitates the recognition and mapping of specific rock types like limestones and marlstones.
• The findings support the use of accessible remote sensing tools in geological studies.