title: Preceramic sequences in the el abra rock-shelters, Colombia.
abstract: A series of crude stone artifacts, characterized by a trimming mainly of the working edge of a single face of a chert flake or a fragment of a nodule, was excavated in the El Abra rock-shelters, north of Bogotá, Colombia. The tools indicate a cultural complex distinct from others that have been described for the Paleo-Indian of South America.
authors.forename: W R
authors.initials: WR
authors.lastname: Hurt
authors.forename: T
authors.initials: T
authors.lastname: Hammen
authors.forename: G C
authors.initials: GC
authors.lastname: Urrego