Petrographical and geomechanical assessment of Widikum and its surroundings’ geological formations (North-West Cameroon) as construction materials

Widikum and its surroundings (North-West Cameroon) are covered with basalts, granites and gneisses. Construction companies use these rocks extensively and indiscriminately for structural loading, pavements, wall cladding as cobblestone and masonry stones. The suitability of these rocks and their petrographic (outcrops mode, structure, color, mineralogical composition and crystals size), physical and geomechanical (specific density, bulk density, Los Angeles abrasion test, and Aggregates crushing test) properties evaluation becomes important for their aforementioned applications. The aim of this study is to characterize on the petrographic and geomechanical level, basalts, granites and gneisses of the locality of Widikum and its surroundings for their use as construction materials. Concerning the petrographical point, granites and gneisses are rich in quartz, feldspar, plagioclase, biotite, amphibole and accessory minerals like opaque minerals and zircon. On the other hand, basalts are ferro-magnesians rich in olivine, pyroxene and opaque minerals. Plagioclase is also a main constituent mineral of this geological formation. On the physical and geomechanical properties, despite their extension on the field, granites have satisfactory density; but, they are least resistant according to the Los Angeles abrasion values. However, basalts are one of the geological formations which are the least extended on the field. They are most dense with the satisfactory to excellent Los Angeles abrasion values. Concerning the gneissic formation, its density and Los Angeles abrasion values are satisfactory. Generally, the aggregates crushing values of studied geological formations attest that they are satisfactory to excellent apart from those of coarse grainy granites. In view of the foregoing, basalts have the best geomechanical qualities and could be used as constituent of construction materials.