An integrated ASTER-based approach for mapping carbonatite and iron oxide-apatite deposits

Abstract

Mapping of carbonatites and related mineral deposits has occupied prominent place in mineral resource exploration programs given their potential to host valuable concentrations of critical metals such as rare earth elements and niobium. Based on spectral characteristics of most indicative minerals for these rocks, a mapping approach was developed using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data. The combination of band rationing outcomes with components from the principal component analysis and minimum noise fraction techniques highlighted the targeted rocks, with the excellent prospective zone representing ∼ 0.2% of the total investigated area. This approach was successfully applied to the Gleibat Lafhouda complex to rapidly delineate carbonatites and iron oxide-apatite ore outcrops. Results were validated through field observations and in-situ geochemical analysis using a portable X-ray fluorescence analyzer. Field data have also served as training data to perform a supervised classification, allowing further improvement of the mapping results.

Keywords:

• Remote sensing
• ASTER data
• mineral resource exploration
• carbonatite
• iron oxide-apatite ore

Acknowledgment

The authors would like to thank the Military services and local authorities for their assistance during the entire period of field missions. The authors wish also to thank Bassou Zayi (UM6P-Geology & Sustainable Mining & UM6P‒OCP Geo-Analytical Lab) and Christophe Nevado and Doriane Delmas (Géosciences Montpellier) for their help in sample and thin section preparations. We thank two anonymous reviewers for their constructive and helpful comments.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was initiated in the frame of FP7-PEOPLE-IRSES project “MEDYNA” 2014–2017 (“Maghreb-EU research staff exchange on geoDYnamics, geohazards, and applied geology in North-west Africa”, Work Package #3: “Deep structures and mantle processes”), and was supported and funded by the UM6P project.