Roughly linear deposit of material left behind by a moving geologic body. In diamond exploration, the term generally refers to tracks of “indicator” minerals such as garnet, ilmenite, and chromite, eroded from a kimberlite by glaciers. As the glaciers move the melting of the ice releases these minerals into the underlying sediment, forming the train. In some cases, kimberlites can be located by following the train back to its “head” or source. Dispersion trains of gold can also be formed when glaciers move overtop an ore body. Dispersion train also refers to the trail of debris left by a volcanic eruption or meteorite impact.