The Soldado Rock section is a valuable stratigraphic key to basal and Upper Eocene of Northern South America. Of the six beds Nos. 2, 6, and 8 are fossiliferous. No. 2 was placed in basal Eocene (Maury, 1912) and correlated with Alabama Midway beds and Marina Farinha beds of Pernambuco. Later thought by Vaughan to be Wilcox, but basal Eocene age corroborated by discovery of same fauna in Marac quarry (Waring, 1926) where it was associated with characteristic basal Eocene species. Age of No. 2 Bed is equivalent to European Montian and Thanetian of England; Bed No. 6, fora-miniferal fauna, referred by Maury and Bagg to Eocene; later by Douville to Oligocene, and by Tobler and Kugler to Upper Eocene. Douville later accepted this. Consensus of opinion of foraminiferal experts now is that Bed No. 6 is Bartonian. This permits Bed 8 to be uppermost Eocene, namely Ludian. Bed No. 8 referred by Maury to Wilcox, raised by Douville, Tobler, and Kugler into Oligocene, now restored to Eocene, but in uppermost member, ...