Airborne images integration for a first cartographic approximation of critical raw materials-rich placers on Santa Marta Beach (Ría de Vigo, NW Spain)

• Type: Article in International Conference Proceedings Book
• Date: 2024

Authors

Ng Cutipa, L (Author) Other; Lobato, A (Author) Other; González, J (Author) Other; Georgalas, G (Author) Other; Zananiri, I (Author) Other; Cardoso Fernandes, J (Author) FCUP; Carvalho, M (Author) Other; Azzalini, A (Author) Other; Araújo, L (Author) Other; Teodoro, AC (Author) Other

Conference proceedings International

Title: Proceedings of SPIE - The International Society for Optical Engineering

Final page: 23

Earth Resources and Environmental Remote Sensing/GIS Applications XV 2024

Edinburgh, 16 September 2024 through 19 September 2024

Indexing

Scopus - 3 Citations

Other information

Authenticus ID: P-017-CA9

DOI: 10.1117/12.3031637

Abstract (EN): Santa Marta Beach (170 m long) is located in the Vigo Estuary, Rias Baixas, NW Spain. Metamorphic and intrusive rocks predominate in the area and these are a good source of placer minerals. Placer deposits occurrences of ilmenite, zircon, garnet, monazite and other heavy and weathering resistant minerals, rich in critical raw materials, have been previously described in the Rias Baixas. The aim of this study is: to better identify quartz veins and pegmatitic dykes in the granitoids by mapping; to delineate areas of coastal placers with reddish to black shading by heavy mineral enhancement; and finally to integrate all data into a Geographic Information System to improve our knowledge of the land-sea interface. An aerial image from the National Aerial Orthophotography Plan (PNOA, 15 cm spatial resolution, from 2020) was used, and an ad hoc UAV (unmanned aerial vehicle) survey was carried out to capture very high spatial resolution images (< 3 cm) in 2024. The results show that UAV is better than PNOA at identifying detailed structural lineaments and is the only survey to delineate heavy mineralised areas (2.60 to 88.20 m2) and to detect dykes and veins. During fieldwork, placer deposits were also observed buried up to 60 cm below the beach surface, forming sub-parallel horizontal layers. The reddish colour, mainly due to the abundance of garnets, is probably due to the metamorphic rocks near Vigo (gneiss, 2-mica schists and mica schists). Quartz veins and pegmatites could be an alternative source of critical minerals to these placers (e.g., cassiterite and spodumene). © 2024 SPIE.

Language: English

Type (Professor's evaluation): Scientific