Sole marks (including groove casts, flute casts, and tool marks) are found on the bottom (sole) surface of turbidite and other clastic beds. They form as moulds preserved in the overlying bed when: (1) currents scour the seafloor (flutes, grooves) or (2) objects dragged by currents incise the substrate (tool marks). Being moulds rather than originals, they are preserved as positive relief on the base of the overlying sandstone bed.