A., "Environmental Effects of Sand and Gravel Mining on Land and Soil in Luku, Minna, Niger State, North Central Nigeria." Journal of Geosciences and Geomatics, vol. 2, no. 2 (2014): 42-49. doi: 10.12691/jgg-2-2-1. 1. Introduction . Sand and gravel mining refers to the process of removing sand or gravel from a place of its occurrence [1].