VNIR-SWIR spectral signatures of the Cu-Co-Ni mineralization and the host rocks of El Aramo (Asturias, España).

The mineralization of the Aramo Plateau is a carbonate-hosted deposit with major Cu-Co-Ni sulphides and arsenides and minor precious metals. There are a few studies on the deposit, but according to Paniagua et al., (1988), it is an epithermal mineralization with an evolutive sequence involving temperatures from 85ºC to 170ºC whose hydrothermal systems were related to the distensive Late-Variscan tectonic activity in the region. Weathering and oxidation of primary sulfides in ore and waste rock materials has resulted in the formation of secondary minerals such as goethite, hematite, malachite, azurite, and others, causing the release of elements, such as Cu or As, to soils, waters or stream sediments (Loredo et al., 2008).

This study is a part of the S34I project (Secure and Sustainable Supply of raw materials for EU Industry) which research and innovate new data-driven methods to analyze Earth Observation data, supporting systematic mineral exploration and continuous monitoring of extraction activities with the aim to increase European autonomy regarding raw materials. This work shows the preliminary results of a study conducted by X-ray diffraction and field VNIR-SWIR spectroscopy related to 1) the identification the mineralogical composition of a very wide group of representative samples from old mines in the area and from the surface of the Aramo Plateau, both outcropping rocks and soils; 2) the spectral response in the VNIR-SWIR wavelength range (the same range that hyperspectral remote sensors use); and 3) the determination of the spectral signatures of the different paragenesis of the mineralization, the host rocks and the soils in which supergenic processes could occur.

Financial support by S34I project (DOI: 10.3030/101091616) is acknowledged.