Ore source is a term used to describe the origin of ore, which is a valuable mineral or metal that can be mined for commercial use. The four crossword solutions for ore source are SEAM, VEIN, MINE, and LODE. A SEAM is a thin layer of ore found between two layers of rock. A VEIN is a narrow channel of ore that runs through a rock formation. A MINE is an excavation in the ground from which ore is extracted. Finally, a LODE is a deposit of ore found within a rock formation.