Título: Biostratigraphic analysis and environmental implications of La Luna Formation, Rio Loro Section, Western Venezuela.

Autor: Kertznus, V. R.

Fuente: Annual AAPG-SEPM Convention, Paper Abstract, p. A93.

Editor: American Association of Petroleum Geologists, Tulsa.

Año: 2002.

Lugar y fecha del Evento: Houston, Texas, 10 al 13 de Marzo.

País de publicación: U. S. A.

Tipo de documento: Abstract.

Resumen

This study is directed to the determination of the age of Rio Loro section based on Premoli Silva & Sliter zonation, as well as to make interpretations of the environmental conditions during the period in which the section was deposited. Those conditions have influence on the morphologic complexity, diversity, and life strategies of the planktonic foraminifers and their assemblages. The biostratigraphic data was correlated to stable isotopes of (delta)13C and (delta)180 curves. The age of the section is geochronologically located between the late Turonian and Campanian. Environmentally, euxinic conditions prevailed from its beginning (late Turonian-Coniacian) being progressively increased until the mid Santonian, where more oxygenated conditions appear and become more evident toward the early Campanian. Although La Luna Formation was depositad in a transgressive period characterized by low oxygenation and oligotrophic stable conditions that allowed the development of stratification in the water column, the overall section shows three periods, characterized by greater oxygenation and representing abrupt changes toward eutrophic conditions that favor the development of opportunist organisms, as well as assemblages dominated by benthonic organisms.