Dinoflagellate cyst counts of ODP Site 1081, Benguela Upwelling, Miocene-Pliocene


Using the Late Miocene to Pliocene organic-walled dinoflagellate cyst record of ODP Site 1081 we reconstruct and discuss the early upwelling history over the Walvis Ridge with a special focus on the movement of the Angola-Benguela Front (ABF). We suggest that during the Late Miocene the Angola Current flowed southwards over the Walvis Ridge more frequently than today because the ABF was probably located further south as a result of a weaker meridional temperature gradient. A possible strengthening of the meridional gradient during the latest Miocene to early Pliocene in combination with uplift of south-western Africa intensified the upwelling along the coast and increased the upwelling's filaments over the Walvis Ridge. An intermediate period from 6.2 to 5.5 Ma is shown by the dominance of Habibacysta tectata, cysts of a cool-tolerant dinoflagellate known from the northern Atlantic, indicating changing oceanic conditions contemporaneous with the Messinian Salinity Crisis. From 4.3 Ma on, the upwelling signal got stronger again and waters were well-mixed and nutrient-rich. Our results indicate a northward migration of the ABF as early as 7 Ma and the initial stepwise intensification of the BUS.

Supplement to: Hötzel, Sebastian; Dupont, Lydie M; Marret, Fabienne; Jung, Gerlinde; Wefer, Gerold (2016): Steps in the intensification of Benguela upwelling over the Walvis Ridge during Miocene and Pliocene. International Journal of Earth Sciences, 1-13

DOI https://doi.org/10.1594/PANGAEA.858185
Related Identifier https://doi.org/10.1007/s00531-016-1309-0
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.858185
Creator Hötzel, Sebastian; Dupont, Lydie M ORCID logo; Marret, Fabienne ORCID logo; Jung, Gerlinde; Wefer, Gerold ORCID logo
Publisher PANGAEA
Publication Year 2016
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 3408 data points
Discipline Earth System Research
Spatial Coverage (11.319 LON, -19.620 LAT); Benguela Current, South Atlantic Ocean
Temporal Coverage Begin 1997-09-09T02:00:00Z
Temporal Coverage End 1997-09-11T21:15:00Z