Oil in the Monterey California Formation Los Angeles to Santa Maria, California July 20–24, Volume T311

Published by the American Geophysical Union as part of the Field Trip Guidebooks Series, Volume 311.

Diatomaceous rocks and their diagenetic equivalents, chert, porcelanite and siliceous mudstone are abundant in Miocene deposits of the Pacific region. Of these, the Monterey Formation is the best known and most extensive. It is present throughout large parts of the state of California (Figure 1) and is in places over three kilometers thick. In addition, it includes the largest diatomite quarry in the world and more importantly, is the source and reservoir for much of the oil produced in California (Figure 2).