The Greenhouse - Icehouse Transition : a dinoflagellate perspective
Through the analysis of the stratigraphic and spatial distribution of organic walled dinoflagellate cysts (dinocysts) from climatologically and oceanographically key sites, this project aims to contribute to a better understanding of the Eocene-Oligocene (E/O) environmental changes and their timing....
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Stockholms universitet, Institutionen för geologi och geokemi
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ftstockholmuniv:oai:DiVA.org:su-1073 2023-05-15T13:33:25+02:00 The Greenhouse - Icehouse Transition : a dinoflagellate perspective van Mourik, Caroline A. 2006 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-1073 eng eng Stockholms universitet, Institutionen för geologi och geokemi Stockholm : Institutionen för geologi och geokemi Meddelanden från Stockholms universitets institution för geologi och geokemi, 1101-1599 1101-1599 http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-1073 urn:isbn:91-7155-227-8 info:eu-repo/semantics/openAccess Eocene - Oligocene dinoflagellate cysts biostratigraphy paleoecology NATURAL SCIENCES NATURVETENSKAP Doctoral thesis, comprehensive summary info:eu-repo/semantics/doctoralThesis text 2006 ftstockholmuniv 2023-02-23T21:38:18Z Through the analysis of the stratigraphic and spatial distribution of organic walled dinoflagellate cysts (dinocysts) from climatologically and oceanographically key sites, this project aims to contribute to a better understanding of the Eocene-Oligocene (E/O) environmental changes and their timing. A central issue is to identify the global environmental changes which are responsible for the Eocene cooling and its underlying mechanisms with the focus on the Oligocene isotope-1 (Oi-1) event, thought to mark the onset of major Antarctic glaciation. Two low-latitude sites were selected, Blake Nose (western North Atlantic) and Massignano (central Italy). For the first time a coherent taxonomy and biostratigraphy of dinocysts was established for the late Eocene at these latitudes. A high resolution correlation was established between the Massignano E/O Stratotype Section and the stratigraphically more extended ‘Massicore’. The composite section was used to analyse sea surface temperature (SST) change across the greenhouse-icehouse transition by means of dinocyst distribution. At Massignano, the Oi-1 event was recognised both qualitatively and quantitatively. In the power spectrum of the SSTdino the ~100 and ~400 kyr eccentricity cycles may be distinguished and correlated with La04. When orbitally tuned, the E/O GSSP dates ~100 kyr older than the Oi-1 event. The boundary’s age could either be ~33.75 or ~34.1 Ma, both differ significantly from the ~33.9 Ma age in the GTS 2004. Furthermore, when the data from the low-latitude sites were combined with extensive datasets from the Proto North Atlantic and adjacent regions, a suite of species sensitive to changes in SST was recognised. Their first and last occurrences reflect seven distinct phases of decreasing SSTs during the Middle Eocene to earliest Oligocene. These results clearly indicate that atmospheric cooling together with higher frequency orbital forcing played a key role in the transition from the Greenhouse to the Icehouse world. Doctoral or Postdoctoral Thesis Antarc* Antarctic North Atlantic Stockholm University: Publications (DiVA) Antarctic |
institution |
Open Polar |
collection |
Stockholm University: Publications (DiVA) |
op_collection_id |
ftstockholmuniv |
language |
English |
topic |
Eocene - Oligocene dinoflagellate cysts biostratigraphy paleoecology NATURAL SCIENCES NATURVETENSKAP |
spellingShingle |
Eocene - Oligocene dinoflagellate cysts biostratigraphy paleoecology NATURAL SCIENCES NATURVETENSKAP van Mourik, Caroline A. The Greenhouse - Icehouse Transition : a dinoflagellate perspective |
topic_facet |
Eocene - Oligocene dinoflagellate cysts biostratigraphy paleoecology NATURAL SCIENCES NATURVETENSKAP |
description |
Through the analysis of the stratigraphic and spatial distribution of organic walled dinoflagellate cysts (dinocysts) from climatologically and oceanographically key sites, this project aims to contribute to a better understanding of the Eocene-Oligocene (E/O) environmental changes and their timing. A central issue is to identify the global environmental changes which are responsible for the Eocene cooling and its underlying mechanisms with the focus on the Oligocene isotope-1 (Oi-1) event, thought to mark the onset of major Antarctic glaciation. Two low-latitude sites were selected, Blake Nose (western North Atlantic) and Massignano (central Italy). For the first time a coherent taxonomy and biostratigraphy of dinocysts was established for the late Eocene at these latitudes. A high resolution correlation was established between the Massignano E/O Stratotype Section and the stratigraphically more extended ‘Massicore’. The composite section was used to analyse sea surface temperature (SST) change across the greenhouse-icehouse transition by means of dinocyst distribution. At Massignano, the Oi-1 event was recognised both qualitatively and quantitatively. In the power spectrum of the SSTdino the ~100 and ~400 kyr eccentricity cycles may be distinguished and correlated with La04. When orbitally tuned, the E/O GSSP dates ~100 kyr older than the Oi-1 event. The boundary’s age could either be ~33.75 or ~34.1 Ma, both differ significantly from the ~33.9 Ma age in the GTS 2004. Furthermore, when the data from the low-latitude sites were combined with extensive datasets from the Proto North Atlantic and adjacent regions, a suite of species sensitive to changes in SST was recognised. Their first and last occurrences reflect seven distinct phases of decreasing SSTs during the Middle Eocene to earliest Oligocene. These results clearly indicate that atmospheric cooling together with higher frequency orbital forcing played a key role in the transition from the Greenhouse to the Icehouse world. |
format |
Doctoral or Postdoctoral Thesis |
author |
van Mourik, Caroline A. |
author_facet |
van Mourik, Caroline A. |
author_sort |
van Mourik, Caroline A. |
title |
The Greenhouse - Icehouse Transition : a dinoflagellate perspective |
title_short |
The Greenhouse - Icehouse Transition : a dinoflagellate perspective |
title_full |
The Greenhouse - Icehouse Transition : a dinoflagellate perspective |
title_fullStr |
The Greenhouse - Icehouse Transition : a dinoflagellate perspective |
title_full_unstemmed |
The Greenhouse - Icehouse Transition : a dinoflagellate perspective |
title_sort |
greenhouse - icehouse transition : a dinoflagellate perspective |
publisher |
Stockholms universitet, Institutionen för geologi och geokemi |
publishDate |
2006 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-1073 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic North Atlantic |
genre_facet |
Antarc* Antarctic North Atlantic |
op_relation |
Meddelanden från Stockholms universitets institution för geologi och geokemi, 1101-1599 1101-1599 http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-1073 urn:isbn:91-7155-227-8 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766042076188770304 |