Biostratigraphy of Neogene Sedimentary Succession in the Macuspana Basin, Southern Gulf
of Mexico
Narváez, Yanina1,
Javier Helenes1, José Manuel Del Moral-Domínguez2, Víctor Manuel Martínez-Morales2 (1) Centro de Investigación Científica y de Educación Superior de Ensenada,
Baja California, Mexico (2) PEMEX, Región Sur, Laboratorio de Paleontología y Petrografía,
Mexico
Neogene strata in two wells
from the southern of Gulf of Mexico were examined for
calcareous microfossils. The onshore part of studied basin includes shallow
marine clastic sediments with few microfossil markers
within a complex structural setting. Calcareous nannofossil
and planktonic foraminifera results presented here
increase the definition and resolution of the Neogene
biostratigraphic framework in the basin. Ages were
assigned on the basis of last occurrences (downhole
first appearance) of calcareous nannofossil and planktonic foraminifera events. Benthic foraminifera
biofacies and calcareous nannoplankton
paleoenvironment analysis were used in paleobathymetric interpretations. Index fossils for age
determinations included following taxa: Calcidiscus macintyrei
(Pleistocene to Pliocene), Sphenolithus abies and Reticulofenestra pseudoumbilicus (Early Pliocene), Discoaster
quinqueramus and Discoaster
berggrenii (Late Miocene), Globorotalia
obesa, Globorotalia mayeri and Sphenolithus heteromorphus (Middle Miocene). Combination of paleontological and wire log data allows the definition of
more than one stratigraphic sequence and third order cycle.
Our data indicates a depositional hiatus in the late Miocene to Pliocene
interval. Biostratigraphic integration of diverse
wells of this sedimentary basin will help clarify the regional chronostratigraphic framework. This framework will surely
help model the geologic evolution and hydrocarbon exploration in Neogene intervals from southeastern Mexico.