Close to Bowie's submerged summit, former coastlines cut by wave actions and beach deposits show that the submarine volcano would once have stood above sea level, as either a single volcanic island or as a small cluster of shoals that would have been volcanically active.
22.
Many early hand axes appear to be made from simple rounded pebbles ( from river or beach deposits ), it is necessary to detach a'starting flake', often much larger than the rest of the flakes ( due to the oblique angle of a rounded pebble requiring greater force to detach it ), thus creating an asymmetry.
23.
The Lower Shiawassee is bordered by a low-relief till plain overlain by relatively impermeable and are poorly-drained fine-grained glacial lake clays and relict beach deposits that were deposited over a several thousand-year period when glacial Lake Saginaw covered much of the area, after the most recent retreat of the ice at the end of the Wisconsin glaciation.