A pebble-cobble deposit in Monterey Bay, California

A deposit of pebbles and cobbles was discovered in approximately 60 fm of water on the continental shelf in Monterey Bay, California.Samples were taken in the area and the extent of the deposit was deter- mined.The material was characterized as well rounded, moderately well sorted coarse pebbles derived mainly from the granites of the Santa Lucia Formation with lesser amounts of alluvium from the Salinas Drain- age Basin which flows into Monterey Bay.It was established that the deposit probably represents a marine terrace of Pleistocene Age, indicating a relative lowering of sea level of about 330 to 360 ft.This appears to be the first reported evidence of submerged marine terraces in Northern California.