A complete terrestrial Oligocene magnetobiostratigraphy from the Ebro Basin, Spain

The integrated litho-, bio- and magnetostratigraphic cross-correlation of 1 1 continuous and correlatable sections in the southeastern Ebro Basin (NE S pain) produced a complete Oligocene magnetic polarity stratigraphy ranging from latest Eocene to earliest Miocene. The magnetic polarity zonation of t he different alluvial and shallow lacustrine sections has been correlated t o the GPTS using fossil mammals and the distinct sequence and pattern of po larity reversals. The composite magnetic polarity sequence defines a contin uous sequence from Chron C15n to Chron 6Cn.2n, from 34.8 to 23.7 Ma (late E ocene-early Miocene). In addition, a few short normal and reverse polarity events that correlate to cryptochrons in the GPTS are found (i.e. in C11n.1 r and C8n.1r). The resulting regional magneto-biostratigraphic framework ba sed on fossil mammals is proposed to refine the dating of the European Olig ocene biochronological mammal Paleogene units and correlate them with the s tandard Oligocene marine stages and the North American land mammal ages. Th e magnetochronology now established enables more precise dating of the late Eocene and Oligocene paleofloristic and paleofaunistic changes in southwes tern Europe, which were coeval to ongoing global paleoclimatic and paleocea nographic changes on Earth caused by high latitude cooling and ice sheet de velopment in eastern Antarctica. (C) 2001 Elsevier Science B.V. All rights reserved.