Detecting Lithium (Li) Mineralizations from Space: Current Research and Future Perspectives

Abstract

Optical and thermal remote sensing data have been an important tool in geological exploration for certain deposit types. However, the present economic and technological advances demand the adaptation of the remote sensing data and image processing techniques to the exploration of other raw materials like lithium (Li). A bibliometric analysis, using a systematic review approach, was made to understand the recent interest in the application of remote sensing methods in Li exploration. A review of the application studies and developments in this field was also made. Throughout the paper, the addressed topics include: (i) achievements made in Li exploration using remote sensing methods; (ii) the main weaknesses of the approaches; (iii) how to overcome these difficulties; and (iv) the expected research perspectives. We expect that the number of studies concerning this topic will increase in the near future and that remote sensing will become an integrated and fundamental tool in Li exploration.

Semi-Automatization of Support Vector Machines to Map Lithium (Li) Bearing Pegmatites

“…This can be related or accentuated by the low ratio between pegmatite size and the satellite image spatial resolution. This issue was vastly explained in previous studies [7,32]. Another major concern in ML and deep learning (DL) remote sensing applications is the ability to transfer learning between case studies [52].…”

“…Spectral studies are being conducted using a laboratory spectroradiometer to build a spectral database of Li-bearing minerals. Moreover, as stated by Cardoso-Fernandes, et al [7], the knowledge on the alteration halos associated with Li-pegmatites could favor alteration mapping techniques, thus increasing the size of the target areas and possibly allowing to vector near-surface hidden dykes. For that, more than 70 host-rocks samples are being characterized through geochemical studies.…”

“…As mentioned before, pegmatite exposition can be very small when compared with the spatial resolution of several free satellite products [7,32]. Despite the fact that lack of thermal band can limit the applicability of Sentinel-2 images in Li-pegmatite identification [2], its medium to high spatial resolution (10-60 m) may be crucial in a classification exercise where the target class presents the lowest exposition.…”

“…With that goal in mind, some authors have attempted to identify Li-bearing pegmatites with different remote sensing data (ASTER, Landsat-5, Landsat-8, and Sentinel-2) and different image processing techniques [1][2][3][4][5][6]. Cardoso-Fernandes, et al [7] recently reviewed the approaches and developments made to Li-exploration using remote sensing data and image processing techniques, pointing out their weaknesses and strengths.…”

Newly Discovered Triassic Lithium Deposits in the Dahongliutan Area, NorthWest China: A Case Study for the Detection of Lithium-Bearing Pegmatite Deposits in Rugged Terrains Using Remote-Sensing Data and Images

“…The method of using satellite images for mineral exploration begins with the compilation of information, which is commonly done in a Geographic Information System (GIS) environment. This includes available records of exploration, geo-referenced geological maps, and initial interpretations of satellite images and orthorectified aerial photographs (where available) (Dimmell et al, 2005;Selway et al, 2005;Scogings et al, 2016;Steiner, 2018;Cardoso-Fernandes et al, 2019a;Cardoso-Fernandes et al, 2019b;Steiner, 2019a;Steiner, 2019b;Cardoso-Fernandes et al, 2020a;Cardoso-Fernandes et al, 2020b). This data is initially used to define areas that might be prospective for economic concentrations of minerals, where regional geochemistry sampling and initial geological mapping is commenced.…”