--> Abstract: Paleoenvironments and Biofacies Based from Eocene Foraminifera of the Pauji Formation of the Area Zulia East, Western Venezuela, by Janieny Medina; #90078 (2008)

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Paleoenvironments and Biofacies Based from Eocene Foraminifera of the Pauji Formation of the Area Zulia East, Western Venezuela

Janieny Medina
Exploracion, Gerencia de Operaciones Exploratorias Occidente, PDVSA, Maracaibo, Venezuela

In the southeastern Zulia State, the approximately 1300 feet-thick Paují Formation is a marine transgressive fossiliferous unit composed of dark-gray shales at the top, and medium to fine grained, gray sandstones below. It unconformably underlies the Miocene La Rosa Formation and overlies the Eocene Misoa Formation. A detailed micropaleontological study of this formation was carried out using cutting samples from three different wells. The fossiliferous shales yielded three biofacies defined by 1) key species and 2) abundant and characteristic calcareous and agglutinated benthic foraminiferal assemblages. The Trochammina teasi, the Cibicides sp. and the Textularia Saggitula Zones, defined by the first appearance and extinction of each of these benthic markers, characterise the lower middle and upper part of the Paují Formation. More than 80 species of calcareous and agglutinated foraminifera have been identified. The assemblages as well as the planktonic/benthonic ratios, allow determination of outer neritic to upper bathyal conditions for the lower part, and upper to middle bathyal paleoenvironments for the middle and upper part of the formation. On the basis of Turborotalia cerroazulensis and Truncorotaloides rohri a Middle Eocene Age (Zones P11/P14 of Bolli & Saunders 1985) has been determined. This transgressive unit constitutes a very useful marker for reservoir correlation and characterisation in the area.

 

AAPG Search and Discover Article #90078©2008 AAPG Annual Convention, San Antonio, Texas