Foraminifera from Upper Jurassic - Lower Cretaceous hydrocarbon seep carbonates and adjacent shales in the Slottsmøya Member, central Spitsbergen
Benthic foraminifera have been extracted from both hydrocarbon seep carbonate structures and adjacent shales of the upper Slottsmøya Member (Agardhfjellet Formation) in central Spitsbergen. The assemblages contain both agglutinated and calcareous taxa, although the shale assemblages are virtually ag...
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ftoslouniv:oai:www.duo.uio.no:10852/12565 2024-10-06T13:46:56+00:00 Foraminifera from Upper Jurassic - Lower Cretaceous hydrocarbon seep carbonates and adjacent shales in the Slottsmøya Member, central Spitsbergen Hjálmarsdóttir, Hanna Rósa Hans Arne Nakrem, Jenø Nagy, Øyvind Hammer 2012-06-27 http://hdl.handle.net/10852/12565 http://urn.nb.no/URN:NBN:no-31287 eng eng http://urn.nb.no/URN:NBN:no-31287 Hjálmarsdóttir, Hanna Rósa. Foraminifera from Upper Jurassic - Lower Cretaceous hydrocarbon seep carbonates and adjacent shales in the Slottsmøya Member, central Spitsbergen. Masteroppgave, University of Oslo, 2012 http://hdl.handle.net/10852/12565 info:ofi/fmt:kev:mtx:ctx&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft.au=Hjálmarsdóttir, Hanna Rósa&rft.title=Foraminifera from Upper Jurassic - Lower Cretaceous hydrocarbon seep carbonates and adjacent shales in the Slottsmøya Member, central Spitsbergen&rft.inst=University of Oslo&rft.date=2012&rft.degree=Masteroppgave URN:NBN:no-31287 166946 122045246 Fulltext https://www.duo.uio.no/bitstream/handle/10852/12565/1/Hjalmarsdottir-Master.pdf Dette dokumentet er ikke elektronisk tilgjengelig etter ønske fra forfatter. Tilgangskode/Access code A forever closedaccess VDP::450 Master thesis Masteroppgave 2012 ftoslouniv 2024-09-12T05:43:54Z Benthic foraminifera have been extracted from both hydrocarbon seep carbonate structures and adjacent shales of the upper Slottsmøya Member (Agardhfjellet Formation) in central Spitsbergen. The assemblages contain both agglutinated and calcareous taxa, although the shale assemblages are virtually agglutinated. The fossil-bearing hydrocarbon seep bodies are the first indication of the existence of cold seeps in Spitsbergen. The preservation of the agglutinated tests from the seep carbonates is excellent. This is due to authigenic precipitation of carbonate, which led to early cementation of the sediment, protecting the foraminiferal tests from compaction. The taxa composing the assemblages are closely related to previously recorded species from the dark shales of the Slottsmøya Member as well as from age equivalent deposits of Arctic Russia and other areas of the Boreal Realm. Some new occurrences are also observed. The relatively high diversity mixed (calcareous-agglutinated) assemblages of the seeps indicate environmental conditions close to those of a normal marine shelf, while the low diversity agglutinated assemblages of the surrounding shales suggest hypoxic conditions. Thus, the hydrocarbon seeps created patches of environments where assemblages with a dominant normal marine aspect could exist on the generally hypoxic basin floor. The foraminifera date the seep carbonate bodies as Late Volgian-Late Ryazanian; an age determination that is in part divergent from ammonite datings previously obtained from these carbonates. Early Volgian-Earliest Ryazanian age is proposed for the succession of shales sampled. This study presents the first systematic report of foraminifera from hydrocarbon seep structures developed at the Jurassic-Cretaceous transition and the first comparison of their faunas with assemblages in the adjacent shales and siltstones. Master Thesis Arctic Foraminifera* Spitsbergen Universitet i Oslo: Digitale utgivelser ved UiO (DUO) Arctic Agardhfjellet ENVELOPE(18.833,18.833,78.083,78.083) Slottsmøya ENVELOPE(17.415,17.415,78.046,78.046) |
institution |
Open Polar |
collection |
Universitet i Oslo: Digitale utgivelser ved UiO (DUO) |
op_collection_id |
ftoslouniv |
language |
English |
topic |
VDP::450 |
spellingShingle |
VDP::450 Hjálmarsdóttir, Hanna Rósa Foraminifera from Upper Jurassic - Lower Cretaceous hydrocarbon seep carbonates and adjacent shales in the Slottsmøya Member, central Spitsbergen |
topic_facet |
VDP::450 |
description |
Benthic foraminifera have been extracted from both hydrocarbon seep carbonate structures and adjacent shales of the upper Slottsmøya Member (Agardhfjellet Formation) in central Spitsbergen. The assemblages contain both agglutinated and calcareous taxa, although the shale assemblages are virtually agglutinated. The fossil-bearing hydrocarbon seep bodies are the first indication of the existence of cold seeps in Spitsbergen. The preservation of the agglutinated tests from the seep carbonates is excellent. This is due to authigenic precipitation of carbonate, which led to early cementation of the sediment, protecting the foraminiferal tests from compaction. The taxa composing the assemblages are closely related to previously recorded species from the dark shales of the Slottsmøya Member as well as from age equivalent deposits of Arctic Russia and other areas of the Boreal Realm. Some new occurrences are also observed. The relatively high diversity mixed (calcareous-agglutinated) assemblages of the seeps indicate environmental conditions close to those of a normal marine shelf, while the low diversity agglutinated assemblages of the surrounding shales suggest hypoxic conditions. Thus, the hydrocarbon seeps created patches of environments where assemblages with a dominant normal marine aspect could exist on the generally hypoxic basin floor. The foraminifera date the seep carbonate bodies as Late Volgian-Late Ryazanian; an age determination that is in part divergent from ammonite datings previously obtained from these carbonates. Early Volgian-Earliest Ryazanian age is proposed for the succession of shales sampled. This study presents the first systematic report of foraminifera from hydrocarbon seep structures developed at the Jurassic-Cretaceous transition and the first comparison of their faunas with assemblages in the adjacent shales and siltstones. |
author2 |
Hans Arne Nakrem, Jenø Nagy, Øyvind Hammer |
format |
Master Thesis |
author |
Hjálmarsdóttir, Hanna Rósa |
author_facet |
Hjálmarsdóttir, Hanna Rósa |
author_sort |
Hjálmarsdóttir, Hanna Rósa |
title |
Foraminifera from Upper Jurassic - Lower Cretaceous hydrocarbon seep carbonates and adjacent shales in the Slottsmøya Member, central Spitsbergen |
title_short |
Foraminifera from Upper Jurassic - Lower Cretaceous hydrocarbon seep carbonates and adjacent shales in the Slottsmøya Member, central Spitsbergen |
title_full |
Foraminifera from Upper Jurassic - Lower Cretaceous hydrocarbon seep carbonates and adjacent shales in the Slottsmøya Member, central Spitsbergen |
title_fullStr |
Foraminifera from Upper Jurassic - Lower Cretaceous hydrocarbon seep carbonates and adjacent shales in the Slottsmøya Member, central Spitsbergen |
title_full_unstemmed |
Foraminifera from Upper Jurassic - Lower Cretaceous hydrocarbon seep carbonates and adjacent shales in the Slottsmøya Member, central Spitsbergen |
title_sort |
foraminifera from upper jurassic - lower cretaceous hydrocarbon seep carbonates and adjacent shales in the slottsmøya member, central spitsbergen |
publishDate |
2012 |
url |
http://hdl.handle.net/10852/12565 http://urn.nb.no/URN:NBN:no-31287 |
long_lat |
ENVELOPE(18.833,18.833,78.083,78.083) ENVELOPE(17.415,17.415,78.046,78.046) |
geographic |
Arctic Agardhfjellet Slottsmøya |
geographic_facet |
Arctic Agardhfjellet Slottsmøya |
genre |
Arctic Foraminifera* Spitsbergen |
genre_facet |
Arctic Foraminifera* Spitsbergen |
op_relation |
http://urn.nb.no/URN:NBN:no-31287 Hjálmarsdóttir, Hanna Rósa. Foraminifera from Upper Jurassic - Lower Cretaceous hydrocarbon seep carbonates and adjacent shales in the Slottsmøya Member, central Spitsbergen. Masteroppgave, University of Oslo, 2012 http://hdl.handle.net/10852/12565 info:ofi/fmt:kev:mtx:ctx&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft.au=Hjálmarsdóttir, Hanna Rósa&rft.title=Foraminifera from Upper Jurassic - Lower Cretaceous hydrocarbon seep carbonates and adjacent shales in the Slottsmøya Member, central Spitsbergen&rft.inst=University of Oslo&rft.date=2012&rft.degree=Masteroppgave URN:NBN:no-31287 166946 122045246 Fulltext https://www.duo.uio.no/bitstream/handle/10852/12565/1/Hjalmarsdottir-Master.pdf |
op_rights |
Dette dokumentet er ikke elektronisk tilgjengelig etter ønske fra forfatter. Tilgangskode/Access code A forever closedaccess |
_version_ |
1812175209936977920 |