8th International Nannoplankton Association Conference
Ma. Antonieta Sánchez R., Patricia Padilla A., Gisela Salazar M., José A. Gómez P., Julio C. González L., Jorge Alvarado A., Gustavo Murillo M., Jorge E. Lugo, Janett Sánchez D.:
The graphic correlation method is a technique that allows consistent and relatively accurate biostratigraphic correlations. This procedure utilises events of extinction and first appearances of the species. These bioevents are used as chronohorizons for correlations.
Data of nannofossils and foraminifera, both planktonic and benthic species, were integrated and interpreted applying the graphic correlation method to two wells (A and B) from SE Mexico. The studied stratigraphic columns correspond to siliciclastic sediments of Middle Miocene-Pliocene age. Four local terraces or discontinuities were identified within the sedimentary succession. Two of these discontinuities are found in the base of the Upper Miocene and the other one at the base of the Lower Pliocene in Well A. Two more were recognised in Well B, one in the Middle Pliocene and a second one in the Middle Miocene.
On the other hand, the analysis of the microflora and microfauna shows variations in the diversity of species. A relatively high diversity during the Late Miocene can be observed, which decreases during Middle Miocene and Early Pliocene time. It is probable that a high rate of sediment supply, derived from the continent and accumulated in the basin, was the cause for the decrease in species diversity.
Copyright © 2000, most recent revision July 26, 2000Tania Hildebrand-Habel (firstname.lastname@example.org)