Dinoflagellate cyst counts and age model from sediment samples of ODP Hole 175-1085A
Sediment samples from ODP Site 1085 were investigated in order to obtain more information on the initiation and development of the Benguela upwelling system during the middle and upper Miocene. In particular, our intent was to establish the causes of the upwelling as well as the response of the upwe...
Published in: | Paleoceanography |
---|---|
Main Authors: | , , , |
Format: | Other/Unknown Material |
Language: | English |
Published: |
PANGAEA
|
Subjects: | |
Online Access: | https://doi.pangaea.de/10.1594/PANGAEA.815984 |
id |
ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.815984 |
---|---|
record_format |
openpolar |
spelling |
ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.815984 2024-09-15T17:44:21+00:00 Dinoflagellate cyst counts and age model from sediment samples of ODP Hole 175-1085A Heinrich, Sonja Zonneveld, Karin A F Bickert, Torsten Willems, Helmut LATITUDE: -29.374410 * LONGITUDE: 13.990110 * DATE/TIME START: 1997-09-26T00:15:00 * DATE/TIME END: 1997-09-29T18:15:00 application/zip, 2 datasets https://doi.pangaea.de/10.1594/PANGAEA.815984 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.815984 Access constraints: access rights needed info:eu-repo/semantics/restrictedAccess Supplement to: Heinrich, Sonja; Zonneveld, Karin A F; Bickert, Torsten; Willems, Helmut (2011): The Benguela upwelling related to the Miocene cooling events and the development of the Antarctic Circumpolar Current: Evidence from calcareous dinoflagellate cysts. Paleoceanography, 26(3), PA3209, https://doi.org/10.1029/2010PA002065 Ocean Drilling Program ODP dataset publication series ftpangaea https://doi.org/10.1029/2010PA002065 2024-07-24T02:31:21Z Sediment samples from ODP Site 1085 were investigated in order to obtain more information on the initiation and development of the Benguela upwelling system during the middle and upper Miocene. In particular, our intent was to establish the causes of the upwelling as well as the response of the upwelling regime to the development of the Antarctic Circumpolar Current. Based on changes in the calcareous dinoflagellate cyst association, we found an initial increase of the dinoflagellate cyst productivity, probably related to the initiation of upwelling about 11.8 Ma ago. Two distinct increases in cyst productivity in conjunction with temperature decreases of the upper water masses reflect upwelling pulses off Namibia and occur at the end of the Miocene cooling events Mi5 (about 11.5 Ma) and Mi6 (about 10.5 Ma). Both cooling events are associated with an ice volume increase in Antarctica and are thought to have led to an increase in southeasterly winds, possibly causing these two upwelling pulses. We demonstrate a decrease in dinoflagellate cyst productivity and enhanced terrigenous input via the Orange River after the Mi5 event. At about 11.1 Ma, the dinoflagellate cyst productivity increases again. The polar cyst species Caracomia arctica occurs here for the first time. This implies an influence of subantarctic mode water and therefore a change in the quality of the upwelling water which allowed the Benguela upwelling to develop into modern conditions. From about 10.4 Ma, C. arctica forms a permanent part of the association, pointing to an establishment of the upwelling regime. Other/Unknown Material Antarc* Antarctic Antarctica PANGAEA - Data Publisher for Earth & Environmental Science ENVELOPE(13.990110,13.990110,-29.374410,-29.374410) Paleoceanography 26 3 |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
Ocean Drilling Program ODP |
spellingShingle |
Ocean Drilling Program ODP Heinrich, Sonja Zonneveld, Karin A F Bickert, Torsten Willems, Helmut Dinoflagellate cyst counts and age model from sediment samples of ODP Hole 175-1085A |
topic_facet |
Ocean Drilling Program ODP |
description |
Sediment samples from ODP Site 1085 were investigated in order to obtain more information on the initiation and development of the Benguela upwelling system during the middle and upper Miocene. In particular, our intent was to establish the causes of the upwelling as well as the response of the upwelling regime to the development of the Antarctic Circumpolar Current. Based on changes in the calcareous dinoflagellate cyst association, we found an initial increase of the dinoflagellate cyst productivity, probably related to the initiation of upwelling about 11.8 Ma ago. Two distinct increases in cyst productivity in conjunction with temperature decreases of the upper water masses reflect upwelling pulses off Namibia and occur at the end of the Miocene cooling events Mi5 (about 11.5 Ma) and Mi6 (about 10.5 Ma). Both cooling events are associated with an ice volume increase in Antarctica and are thought to have led to an increase in southeasterly winds, possibly causing these two upwelling pulses. We demonstrate a decrease in dinoflagellate cyst productivity and enhanced terrigenous input via the Orange River after the Mi5 event. At about 11.1 Ma, the dinoflagellate cyst productivity increases again. The polar cyst species Caracomia arctica occurs here for the first time. This implies an influence of subantarctic mode water and therefore a change in the quality of the upwelling water which allowed the Benguela upwelling to develop into modern conditions. From about 10.4 Ma, C. arctica forms a permanent part of the association, pointing to an establishment of the upwelling regime. |
format |
Other/Unknown Material |
author |
Heinrich, Sonja Zonneveld, Karin A F Bickert, Torsten Willems, Helmut |
author_facet |
Heinrich, Sonja Zonneveld, Karin A F Bickert, Torsten Willems, Helmut |
author_sort |
Heinrich, Sonja |
title |
Dinoflagellate cyst counts and age model from sediment samples of ODP Hole 175-1085A |
title_short |
Dinoflagellate cyst counts and age model from sediment samples of ODP Hole 175-1085A |
title_full |
Dinoflagellate cyst counts and age model from sediment samples of ODP Hole 175-1085A |
title_fullStr |
Dinoflagellate cyst counts and age model from sediment samples of ODP Hole 175-1085A |
title_full_unstemmed |
Dinoflagellate cyst counts and age model from sediment samples of ODP Hole 175-1085A |
title_sort |
dinoflagellate cyst counts and age model from sediment samples of odp hole 175-1085a |
publisher |
PANGAEA |
url |
https://doi.pangaea.de/10.1594/PANGAEA.815984 |
op_coverage |
LATITUDE: -29.374410 * LONGITUDE: 13.990110 * DATE/TIME START: 1997-09-26T00:15:00 * DATE/TIME END: 1997-09-29T18:15:00 |
long_lat |
ENVELOPE(13.990110,13.990110,-29.374410,-29.374410) |
genre |
Antarc* Antarctic Antarctica |
genre_facet |
Antarc* Antarctic Antarctica |
op_source |
Supplement to: Heinrich, Sonja; Zonneveld, Karin A F; Bickert, Torsten; Willems, Helmut (2011): The Benguela upwelling related to the Miocene cooling events and the development of the Antarctic Circumpolar Current: Evidence from calcareous dinoflagellate cysts. Paleoceanography, 26(3), PA3209, https://doi.org/10.1029/2010PA002065 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.815984 |
op_rights |
Access constraints: access rights needed info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1029/2010PA002065 |
container_title |
Paleoceanography |
container_volume |
26 |
container_issue |
3 |
_version_ |
1810491838324277248 |