Late Eocene to Oligocene Events: Molino de Cobo, Betic Cordillera, Spain.

TitleLate Eocene to Oligocene Events: Molino de Cobo, Betic Cordillera, Spain.
Publication TypeJournal Article
Year of Publication1989
AuthorsMolina, E, Keller, G, Madile, N
JournalLate Eocene to Oligocene Events: Molino de Cobo, Betic Cordillera, Spain.
Volume20
Issue3
Start Page491-514
Abstract

Quantitative analysis of upper Eocene to Oligocene planktonic foraminifers and calcareous nannofossils in the Molino de Cobo section, Betic Cordillera, Spain indicate three major extinction evenLS: 1) in the upper Eocene at the extinction of Globigerapsis index, 2) at the Eocene-Oligocene boundary and 3) al tbe lower/upper Oligocene boundary. The Globigerapsis index extinction event in Ibis area coincides with the dramatic abundance decline of the discshaped discoasters (D. saipanensis, D. barbadiensis). This faunal and floral assemblage change coincides with a carbonate dissolution interval. The Eocene-Oligocene boundary extinction event involves five planktonic foraminiferal species, which contrary to common belief did not go extinct simulta~ neously, but stretched out over a 3m intervalo This extinction event is probably related to the isotopic enrichment that signals the development of the psychrosphere, or two layer ocean with cold bottom and warm surface water. The lower/upper O1igocene faunal tumover event involves the extinction of surviving Eocene species and the evolulion of late Oligocene to Miocene species. A short hiatos may be present at this intervalo This faunal turnover is most likely related to global cooling and a major sea level drop.   PDF

URLhttp://wzar.unizar.es/perso/emolina/pdf/Molina1988REM.pdf