Lower Tertiary strata in .the northern Santa Lucia Range of California are correlated by means of planktonic and benthonic foraminifers. Benthonic foraminiferal assemblages from eight stratigraphic sections range in age from Ynezian to possible basal Refugian. The Paleocene mudstone contains a Ynezian benthonic foraminiferal assemblage. The Ulatisian benthonic assemblage of the Lucia Mudstone and the Penutian to Ulatisian benthonic assemblages of the Eocene sandstone and rnudstone unit are associated with planktonic foraminifers referable to Zones P 7-P 8 and P 9. The Church Creek Formation is characterized by a Narizian to possibly Refugian benthonic assemblage. Two questionable associations of early Eocene planktonic foraminifers with Narizian benthonic foraminifers occur near Arroyo Seco Creek. No -age-diagnostic foraminifers were found in The Rocks Sandstone. Data from previous studies, along with our data, suggest a Ulatisian to Narizian age for this unit. Paleoenvironments interpreted from foraminiferal assemblages suggest a general shoaling from lower bathyal or deeper water depths in the middle Paleocene and early Eocene to bathyal water depths during the middle Eocene. In addition, the Ulatisian water depths deepen across the Santa Lucia Range from east to west.
