Late Quaternary upwelling variations in the eastern equatorial Atlantic Ocean as inferred from dinoflagellate cysts, planktonic foraminifera, and organic carbon content

Citation
C. Holl et S. Kemle-von Mucke, Late Quaternary upwelling variations in the eastern equatorial Atlantic Ocean as inferred from dinoflagellate cysts, planktonic foraminifera, and organic carbon content, QUATERN RES, 54(1), 2000, pp. 58-67
Citations number
41
Categorie Soggetti
Earth Sciences
Journal title
QUATERNARY RESEARCH
ISSN journal
00335894 → ACNP
Volume
54
Issue
1
Year of publication
2000
Pages
58 - 67
Database
ISI
SICI code
0033-5894(200007)54:1<58:LQUVIT>2.0.ZU;2-P
Abstract
Analysis of multiple proxies shows that eastern equatorial Atlantic upwelli ng was subdued during isotope stage 5.5, more intense during stages 4, 5.2, 5.4, and 6, and most intense early in stage 2. These findings are based on proxy measures from a core site about 600 km southwest of Liberia. The pro xies include total organic carbon content, the ratio of peridinoid and ocea nic organic-walled dinoflagellate cyst species, accumulation rates of calca reous dinoflagellates, estimates of sea surface paleotemperatures, the diff erence in stable oxygen isotope composition between two species of plankton ic foraminifera that lire at different water depths, and the abundance of t he planktonic foraminifera Neogloboquadrina dutertrei. Most of these parame ters consistently vary directly or inversely with one another. Slight discr epancies between the individual parameters show the usefulness of a multipl e proxy approach to reconstruct paleoenvironments. Our data confirm that no rthern summer insolation strongly influences upwelling in the eastern equat orial Atlantic Ocean. (C) 2000 University of Washington.