Contribution of multispectral remote sensing to mining exploration in the Rehamna Massif, Moroccan Meseta

Mohamed El-Mimouni,Kawtar Benyas,Ahmed Akhssas,Abdellatif Aarab,Abderrazak Hamzaoui,Abdellah Lakhloufi

doi:10.1051/e3sconf/202015003018

Mohamed El-Mimouni, Kawtar Benyas + Show 4 more

Open Access

https://doi.org/10.1051/e3sconf/202015003018

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Abstract

The Western Moroccan Meseta contains mining sites in operation for several decades and others in development. The Rehamna Massif belonging to this, is the subject of this study. The present study reveals new results on the mineralization in this massif. It is based on the synergy of field investigation data and ASTER image analysis (L1T) covering this massif. Through spectral processing, namely the calculation of the band ratios, ACP and MNF, applied to the nine VNIR and SWIR bands of this image, it was possible to reveal the distribution of hydrothermal alteration minerals in the study area. The conjuncture of these data allowed us to select geological targets likely to be of potential mining interest in the massif.

Highlights

Except the phosphate deposits on its borders (Cenozoic cover), the Hercynian Rehamna Massif does not contain lot of current mining activity, unlike the other massifs of the Western Meseta, they have a common geological history
This part of the Rehamna contains orthogneisses [8, 11, 12] dated from the Upper Precambrian [13] covered by Cambrian arkoses, limestones and cipolin, surmounted by the metaconglomerate of kef Elmounib [14] attributed to the lower Devonian, followed by Devonian terrains of Skhour containing phyllites and quartzites [12,15]. iii) Eastern Rehamna, zone limited to the west by the Oulad Zednes fault, and represented by two metamorphic units: lower unit of Lalla Tittaf and upper unit of Ouled Hassine
The analysis of the image included three spectral methods applied to the nine VNIR and short-wave infrared (SWIR) bands: first, band-ratio calculations to identify hydrothermal alteration minerals from possible zones with mining potential, principal component analysis (PCA) and a minimum noise fraction transformation (MNF) were applied on the same bands to highlight selected areas

Summary

Introduction

Except the phosphate deposits on its borders (Cenozoic cover), the Hercynian Rehamna Massif does not contain lot of current mining activity, unlike the other massifs of the Western Meseta, they have a common geological history. Several studies have shown the importance of mapping hydrothermal alteration minerals in mining exploration and identification of mining deposits [1,2,3]. The images generated by the multi and hyperspectral sensors have shown great utility in geological and mineral mapping, and offer a decision support tool upstream of any mining exploration project. The use of these images in the detection of mining sites has become fruitful after the launch of the ETM + (Enhanced Themaic Mapper plus) and ASTER (Advanced Spectral Thermal Emission and Reflection Radiometer) satellites in 1999 [1, 4, 5]

Geological setting

Ore deposit in the Rehamna massif

Bands ratios

PCA technique

Conclusion