Late Pleistocene channel-levee development on Monterey submarine fan, central California

Much of the modern upper (proximal) Monterey fan is a channel-levee complex , the Upper Turbidite Sequence (UTS), that was deeply eroded after the chan nel breached a volcanic ridge to reach a deeper base level. Ages of sedimen t samples collected with the ALVIN submersible from the deepest outcrop wit hin the channel-levee system, 390 m below the adjacent western levee crest, indicate that the UTS deposits accumulated at greater than or equal to 1 m ka(-1) during the last 500 ka. Neogene and Early Pleistocene sediment accu mulation on the fan prior to the UTS was much slower (<0.03 m ka(-1)), and underlying turbidite systems(?) had substantially different morphologic exp ression(s).