A dimension-stone-specific GIS-AHP framework for regional quarry suitability screening in under-mapped Precambrian basement: application to Cameroon’s West Region, Central African Fold Belt

Abstract

Abstract Dimension stone exploration in crystalline basement terrains requires spatially explicit methods that integrate geological potential with environmental, infrastructural, and regulatory constraints. This study develops a GIS-based multi-criteria decision analysis (MCDA) framework combined with Analytic Hierarchy Process (AHP) weighting to evaluate quarry suitability in the West Region of Cameroon. Geological, environmental, topographic and infrastructural criteria were integrated using GIS-AHP to generate a regional quarry suitability model. An additional methodological contribution is the introduction of a suitability density metric, which transforms pixel-based suitability outputs into administrative-unit indicators, enabling interpretation of quarry potential in relation to governance and planning units. This allows identification where suitable rocks occur and where they are spatially concentrated within communes and divisions. Results show that high and very high suitability zones are concentrated in the central-eastern crystalline belt, controlled primarily by granitoid-orthogneiss lithologies, moderate terrain conditions, and reduced environmental constraints. Sensitivity analysis indicates that the spatial pattern is robust under ± 20% perturbations of key AHP weights, although class proportions vary moderately. Field validation at 44 sites confirms broad agreement between regional predictions and quarry-scale observations, while also highlighting scale-dependent mismatches driven by local structural conditions and access constraints. The suitability density metric identifies Foumban as the primary exploration hotspot, with Foumbot, Massangam, Malantouen, Bangangté, Djebem and Bafoussam II as secondary priority communes. Magba is dominated by moderate suitability but still retains localized quarry potential. Overall, the framework provides a transferable screening tool for dimension stone prospectivity and supports spatially informed governance of low-value construction minerals in Precambrian terranes.