Dinoflagellates of sediment core GeoB1523-1

Annemiek Vink; Anja Brune; Christine Höll; Karin A F Zonneveld; Helmut Willems

doi:10.1594/pangaea.56156

Dinoflagellates of sediment core GeoB1523-1

Citation

Vink A, Brune A, Höll C, Zonneveld K A F, Willems H (2000). Dinoflagellates of sediment core GeoB1523-1. PANGAEA - Data Publisher for Earth & Environmental Science. Occurrence dataset https://doi.org/10.1594/pangaea.56156 accessed via GBIF.org on 2024-12-14.

Description

Large numbers of calcareous dinoflagellate cysts and the vegetative calcareous coccoid species Thoracosphaera heimii are generally found in sediments underlying oligotrophic and/or stratified (sub)surface water environments. It is difficult to distinguish between the relative importance of these two environmental parameters on calcareous cyst and T. heimii distribution as they usually covary, but this information is essential if we want to apply cysts properly in the reconstruction of palaeoenvironments and past surface water hydrography. In the multi-proxy core GeoB 1523-1 from the Ceará Rise region in the western equatorial Atlantic Ocean (covering the past 155 ka), periods of greatest oligotrophy are not synchronous with periods of greatest stratification (Rühlemann et al., 1996, doi:10.1016/S0025-3227(96)00048-5; Mulitza et al., 1997, doi:10.1130/0091-7613(1997)025<0335:PFAROP>2.3.CO;2; 335-338; Mulitza et al., 1998, doi:10.1016/S0012-821X(98)00012-0), giving us the unique opportunity to differentiate between the effects of both parameters on cyst accumulation. The calcareous cyst record of the core reflects prominent increases in accumulation rate of nearly all observed species only during the nutrient-enriched but more stratified isotopic (sub)stages 5.5, 5.3, 5.1 and 1. In this respect, the distribution trends in the core are more similar to those of the eastern equatorial upwelling region (GeoB 1105-4) than they are to those of the oligotrophic north-eastern Brazilian continental slope (GeoB 2204-2), even though temporal changes in bioproductivity are principally in antiphase between the eastern and western equatorial regions. We conclude that stratification of the upper water column and the presence of a well-developed thermocline are probably the more important factors controlling cyst distribution in the equatorial Atlantic, whereas the state of oligotrophy secondarily influences cyst production within a well-stratified environment.

Taxonomic Coverages

Protozoa
rank: kingdom
Myzozoa
rank: kingdom

Geographic Coverages

Event: GeoB1523-1, Amazon Fan ;

Bibliographic Citations

Contacts

Annemiek Vink
originator

Anja Brune
originator

Christine Höll
originator

Karin A F Zonneveld
originator

Helmut Willems
originator

metadata author
PANGAEA - Data Publisher for Earth & Environmental Science
email: info@pangaea.de
homepage: https://www.pangaea.de

Frank-Oliver Glöckner
administrative point of contact

Robert Huber
administrative point of contact