Title
Onocerane attests to dry climatic events during the Quaternary in the tropics
Date Issued
01 March 2004
Access level
open access
Resource Type
journal article
Author(s)
Jacob J.
Disnar J.R.
Boussafir M.
Ledru M.P.
Albuquerque A.L.S.
Universidad Federal Fluminense
Research Institute Development
Abstract
An unusual molecular fossil (onocerane I) has been detected in Quaternary lacustrine sediments (Lagoa do Caçó, NE Brazil) for the first time. This component was initially thought to attest to the former presence of ferns or club mosses. From consideration of possible plant precursors of onocerane-related molecules recorded in the literature and comparison with palynological results and palaeoclimatic data, we here provide evidence that club mosses and ferns cannot account as sources of onocerane I in this setting. Onocerane I is abundant in the lipid extracts of sediments deposited during the two driest periods recorded in Northern Brazil (Last Glacial Maximum and Younger Dryas). This component is therefore suspected to be diagnostic of the development of plants adapted to dry or semi-arid conditions in this region. © 2003 Elsevier Ltd. All rights reserved.
Start page
289
End page
297
Volume
35
Issue
3
Language
English
OCDE Knowledge area
MeteorologÃa y ciencias atmosféricas
Scopus EID
2-s2.0-1442340232
Source
Organic Geochemistry
ISSN of the container
01466380
Sponsor(s)
We are grateful to Dr. Peter Dean (Cambio, UK) and Dr. Sean Mayes (University of Canterbury, UK) for useful discussions on the role of onocerin in Ononis sp. We are fully undebted to Professor M.J. Pearson for providing the Nigerian crude oil sample and to Catherine Hanni (Brown University) for improving the English. We also thank Dr. H.P. Nytoft and Professor M.J. Pearson for their comments which significantly improved the quality of this manuscript. The research was supported by an IRD (France)-CNPq (Brasil) convention and an ISTO (UMR 6113 du CNRS, France)-IRD cooperation. One of us (J. J.) received financial support from the Conseil Régional du Centre.
Sources of information:
Directorio de Producción CientÃfica
Scopus