The identification of offshore mineral resources in shallow and deep marine regions is of strategic importance, especially in underexplored continental margin environments. Therefore, the exploration of these resources relies heavily on suitable seafloor mapping. This research presents a mineral prospectivity map of the offshore Lagos region, Nigeria, in the Atlantic Ocean, using Multibeam Echo Sounder (MBES) bathymetry and backscatter datasets. In this study, MBES data were collected directly in 2025 through a marine survey in part of the Lagos offshore area, Nigeria.

To ensure data quality during the survey, MBES instrument calibration, such as a patch test, was conducted to correct systematic errors in latency, roll, pitch, and yaw between the sonar head and navigation sensors. Additionally, verification checks were performed both before and during MBES operations to verify system accuracy, consistency, and adherence to survey specifications. The bathymetric data were corrected by removing outliers and filtering, then processed with the Qimera and Mbmax 64 tools.

The cleaned data were used to develop a digital terrain model (DTM) and derived parameters such as slope, aspect, and bathymetric position index (BPI). Data analysis was carried out using Fledermaus and QGIS geospatial tools. The results indicated that the observed depths ranged approximately from -40 metres to -84 metres below sea level, revealing significant topographical variation. The region features plains and gentle slopes with fine to moderately sorted sands, conducive to the accumulation of iron-rich sands and potentially heavy minerals due to slower water movement. It also exhibits steeper slopes, characterised by coarse sands, which can trap heavier minerals and support potential placer deposits.

BPI analysis shows that most of the terrain is flat, including gentle slopes, with only minor rises observed in a few locations. Moving forward, the backscatter data will be processed and analysed to aid in substrate type identification and classification, providing further insights into the region’s geological potential through backscatter signatures and intensity. The bathymetric and backscatter datasets will be combined to produce spatial layers pertinent to the area’s mineral resource potential. This research will provide a basis for further resource evaluations in the Nigerian offshore seas. The outcomes are anticipated to offer significant insights for seabed resource exploitation and facilitate the sustainable growth of the nation’s blue economy.