Bioestratigrafía del Paleoceno y Eoceno de la Cuenca Tampico- Misantla, basada en los foraminíferos planctónicos
A Paleocene-Eocene biostratigraphic scheme of zonation is established for the Tampico-Misantla Basin. Twenty-two Interval-Zones are defined, which are based on the distribution of planktonic foraminifera. The Paleocene/Eocene boundary is placed at the base of Zone T-10 (Globorotalia velascoensis/Globorotalia aragonensis Interval-Zone) The Eocene/Oligocene boundary is defined at the top of Zone T-22 (Globorotalia cerroazulensis/Globorotalia cocoaensis Interval Zone). On the other hand, it is suggested that the stage divisions of the Paleocene and Eocene Series, as stand at present, should be abandoned, because their use in local stratigraphy would cause serious cronostratigraphic missdeterminations and additional mistakes in correlation.