The Marinoan glaciation (Neoproterozoic) in northeast Svalbard
The definitive version is available at onlinelibrary.wiley.com Two separate and distinct diamictite-rich units occur in the mixed carbonate-siliciclastic Polarisbreen Group, which comprises the top kilometer of >7 km of Neoproterozoic strata in the northeast of the Svalbard archipelago. The platf...
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ftunivadelaidedl:oai:digital.library.adelaide.edu.au:2440/34305 2023-12-17T10:30:36+01:00 The Marinoan glaciation (Neoproterozoic) in northeast Svalbard Halverson, G. Maloof, A. Hoffman, P. 2004 http://hdl.handle.net/2440/34305 https://doi.org/10.1111/j.1365-2117.2004.00234.x en eng Blackwell Science Ltd Basin Research, 2004; 16(3):297-324 0950-091X 1365-2117 http://hdl.handle.net/2440/34305 doi:10.1111/j.1365-2117.2004.00234.x http://dx.doi.org/10.1111/j.1365-2117.2004.00234.x Journal article 2004 ftunivadelaidedl https://doi.org/10.1111/j.1365-2117.2004.00234.x 2023-11-20T23:19:11Z The definitive version is available at onlinelibrary.wiley.com Two separate and distinct diamictite-rich units occur in the mixed carbonate-siliciclastic Polarisbreen Group, which comprises the top kilometer of >7 km of Neoproterozoic strata in the northeast of the Svalbard archipelago. The platformal succession accumulated on the windward, tropical to subtropical margin of Laurentia. The older Petrovbreen Member is a thin glacimarine diamictite that lacks a cap carbonate. It contains locally derived clasts and overlies a regional karstic disconformity that was directly preceded by a large (>10‰) negative δ13C anomaly in the underlying shallow-marine carbonates. This anomaly is homologous to anomalies in Australia, Canada and Namibia that precede the Marinoan glaciation. The younger and thicker Wilsonbreen Formation comprises terrestrial ice-contact deposits. It contains abundant extrabasinal clasts and is draped by a transgressive cap dolostone 3–18 m thick. The cap dolostone is replete with sedimentary features strongly associated with post-Marinoan caps globally, and its isotopic profile is virtually identical to that of other Marinoan cap dolostones. From the inter-regional perspective, the two diamictite-rich units in the Polarisbreen Group should represent the first and final phases of the Marinoan glaciation. Above the Petrovbreen diamictite are 200 m of finely laminated, dark olive-coloured rhythmites (MacDonaldryggen Member) interpreted here to represent suspension deposits beneath shorefast, multi-annual sea ice (sikussak). Above the suspension deposits and below the Wilsonbreen diamictites is a <30-m-thick regressive sequence (Slangen Member) composed of dolomite grainstone and evaporitic supratidal microbialaminite. We interpret this sabkha-like lagoonal sequence as an oasis deposit that precipitated when local marine ice melted away under greenhouse forcing, but while the tropical ocean remained covered due to inflow of sea glaciers from higher latitudes. It appears that the Polarisbreen ... Article in Journal/Newspaper glacier* Sea ice Svalbard The University of Adelaide: Digital Library Canada Petrovbreen ENVELOPE(18.185,18.185,78.699,78.699) Svalbard Svalbard Archipelago Basin Research 16 3 297 324 |
institution |
Open Polar |
collection |
The University of Adelaide: Digital Library |
op_collection_id |
ftunivadelaidedl |
language |
English |
description |
The definitive version is available at onlinelibrary.wiley.com Two separate and distinct diamictite-rich units occur in the mixed carbonate-siliciclastic Polarisbreen Group, which comprises the top kilometer of >7 km of Neoproterozoic strata in the northeast of the Svalbard archipelago. The platformal succession accumulated on the windward, tropical to subtropical margin of Laurentia. The older Petrovbreen Member is a thin glacimarine diamictite that lacks a cap carbonate. It contains locally derived clasts and overlies a regional karstic disconformity that was directly preceded by a large (>10‰) negative δ13C anomaly in the underlying shallow-marine carbonates. This anomaly is homologous to anomalies in Australia, Canada and Namibia that precede the Marinoan glaciation. The younger and thicker Wilsonbreen Formation comprises terrestrial ice-contact deposits. It contains abundant extrabasinal clasts and is draped by a transgressive cap dolostone 3–18 m thick. The cap dolostone is replete with sedimentary features strongly associated with post-Marinoan caps globally, and its isotopic profile is virtually identical to that of other Marinoan cap dolostones. From the inter-regional perspective, the two diamictite-rich units in the Polarisbreen Group should represent the first and final phases of the Marinoan glaciation. Above the Petrovbreen diamictite are 200 m of finely laminated, dark olive-coloured rhythmites (MacDonaldryggen Member) interpreted here to represent suspension deposits beneath shorefast, multi-annual sea ice (sikussak). Above the suspension deposits and below the Wilsonbreen diamictites is a <30-m-thick regressive sequence (Slangen Member) composed of dolomite grainstone and evaporitic supratidal microbialaminite. We interpret this sabkha-like lagoonal sequence as an oasis deposit that precipitated when local marine ice melted away under greenhouse forcing, but while the tropical ocean remained covered due to inflow of sea glaciers from higher latitudes. It appears that the Polarisbreen ... |
format |
Article in Journal/Newspaper |
author |
Halverson, G. Maloof, A. Hoffman, P. |
spellingShingle |
Halverson, G. Maloof, A. Hoffman, P. The Marinoan glaciation (Neoproterozoic) in northeast Svalbard |
author_facet |
Halverson, G. Maloof, A. Hoffman, P. |
author_sort |
Halverson, G. |
title |
The Marinoan glaciation (Neoproterozoic) in northeast Svalbard |
title_short |
The Marinoan glaciation (Neoproterozoic) in northeast Svalbard |
title_full |
The Marinoan glaciation (Neoproterozoic) in northeast Svalbard |
title_fullStr |
The Marinoan glaciation (Neoproterozoic) in northeast Svalbard |
title_full_unstemmed |
The Marinoan glaciation (Neoproterozoic) in northeast Svalbard |
title_sort |
marinoan glaciation (neoproterozoic) in northeast svalbard |
publisher |
Blackwell Science Ltd |
publishDate |
2004 |
url |
http://hdl.handle.net/2440/34305 https://doi.org/10.1111/j.1365-2117.2004.00234.x |
long_lat |
ENVELOPE(18.185,18.185,78.699,78.699) |
geographic |
Canada Petrovbreen Svalbard Svalbard Archipelago |
geographic_facet |
Canada Petrovbreen Svalbard Svalbard Archipelago |
genre |
glacier* Sea ice Svalbard |
genre_facet |
glacier* Sea ice Svalbard |
op_source |
http://dx.doi.org/10.1111/j.1365-2117.2004.00234.x |
op_relation |
Basin Research, 2004; 16(3):297-324 0950-091X 1365-2117 http://hdl.handle.net/2440/34305 doi:10.1111/j.1365-2117.2004.00234.x |
op_doi |
https://doi.org/10.1111/j.1365-2117.2004.00234.x |
container_title |
Basin Research |
container_volume |
16 |
container_issue |
3 |
container_start_page |
297 |
op_container_end_page |
324 |
_version_ |
1785583588707663872 |