METHOD FOR PALYNOLOGICAL PREPARATION: A TOOL TO INCREASE THE RECOVERY OF DINOFLAGELLATES
ANTONIO D. DE OLIVEIRA 1, JOÃO G. MENDONÇA-FILHO 1, MARCELO A. CARVALHO 1, TAÍSSA R. MENEZES 1, CECÍLIA C. LANA 2AND WOLFRAM W. BRENNER 3
1 Universidade Federal do Rio de Janeiro, IGEO / DEGEO / Laboratório de Palinofácies e Fácies Orgânica.
2 PETROBRAS / CENPES / BPA - Gerência de Bioestratigrafia e Paleoecologia Aplicada.
3 Christian-Albrechts-Universität Kiel, Forschungszentrum für marine Geowissenschaften.
Presented by DIOGENES DE ALMEIDA CAMPOS
The purpose of this project is to develop a method that improves the recovery of dinoflagellates of holocenic and pleistocenic sediments from the Campos Basin. Samples were customarily prepared by the employment of the standard method for palynofacies study, whose main goal is to eliminate the mineral constituents by acids, thus concentrating the palynomorph assemblages on palynological slides. Here we improve this method applying a simple procedure: the panning process to eliminate the excess of heavy minerals in the samples after the use of hydrofluoric acid. Moreover, detergent and ultra-sonic to dissociate the amorphous organic matter were employed. An additional difference is the sieving of the suspension material (after decantation) which was previously discarded. There is also no necessity for the use of acetolysis (a standard procedure in palynological preparation of Quaternary samples), resulting in better preservation of dinoflagellates. The size of the sample can also be reduced (6 grams) which is another advantage of the present procedure.
To confirm the effectiveness of the method described here, one sample was prepared following both procedures. Using the traditional method, only two dinoflagellates were found, which made up only 1% of all palynomorphs recovered. By following the procedures presented here, the number of dinoflagellates has increased, reaching 78% of all palynomorphs. It should be noted that the increase of the dinoflagellates is not at the expense of other palynomorphs, because in both procedures there is no significant difference in the palynomorph count.
According to these results, it was possible to confirm that the new methodology employed here for the samples of the pleistocenic and holocenic sediments of the Campos Basin has improved extraordinarily the recovery of dinoflagellates, and might have a widespread use for the recovery of those microfossils in other deposits. ( December 20, 2001 ).
Publication Dates
-
Publication in this collection
17 July 2002 -
Date of issue
June 2002
