title: "Pliocene-Pleistocene" Boundary in Deep-Sea Sediments.
abstract: Changes in planktonic microfossil assemblages in Atlantic sediment cores, at approximately the beginning of the Quaternary, correspond in a general way with those recognized in Pacific cores. How closely the horizon marked by these changes approximates to the Pliocene-Pleistocene boundary is not yet established.
authors.forename: W R
authors.initials: WR
authors.lastname: Riedel
authors.forename: M N
authors.initials: MN
authors.lastname: Bramlette
authors.forename: F L
authors.initials: FL
authors.lastname: Parker