The nature of Ordovician limestone-marl alternations in the Oslo-Asker District (Norway): Witnesses of primary glacio-eustasy or diagenetic rhythms?
Amberg CEA, Collart T, Salenbien W, Egger LM, Munnecke A, Nielsen AT, Monnet C, Hammer Ø, Vandenbroucke TR (2016)
Publication Language: English
Publication Status: Published
Publication Type: Journal article, Original article
Publication year: 2016
Journal
Publisher: Nature Publishing Group
Book Volume: 6
Article Number: 18787
URI: http://www.nature.com/articles/srep18787
DOI: 10.1038/srep18787
Open Access Link: http://www.nature.com/articles/srep18787.pdf
Abstract
Ordovician limestone-marl alternations in the Oslo-Asker District have been interpreted as signaling glacio-eustatic lowstands, which would support a prolonged â €œ Early Palaeozoic Icehouseâ €. However, these rhythmites could alternatively reflect differential diagenesis, without sedimentary trigger. Here, we test both hypotheses through one Darriwilian and three Katian sections. Our methodology consists of a bed-by-bed analysis of palynological (chitinozoan) and geochemical (XRF) data, to evaluate whether the limestone/marl couplets reflect an original cyclic signal. The results reveal similar palynomorph assemblages in limestones and marls. Exceptions, which could be interpreted as reflecting palaeoclimatological fluctuations, exist at the species level: Ancyrochitina bornholmensis seems to be more abundant in the marl samples from the lower Frognerkilen Formation on Nakkholmen Island. However, these rare cases where chitinozoans differ between limestone/marl facies are deemed insufficient for the identification of original cyclicity. The geochemical data show a near-perfect correlation between insoluble elements in the limestone and the marls, which indicates a similar composition of the potential precursor sediment, also in the Frognerkilen Formation. This is consistent with the palynological data. Although an original cyclic pattern could still be recorded by other, uninvestigated parameters, our palaeontological and geochemical data combined do not support the presence of such a signal.
Authors with CRIS profile
Involved external institutions
Ruprecht-Karls-Universität Heidelberg
Germany (DE)
Universiteit Gent (UGent) / Ghent University
Belgium (BE)
University of Oslo
Norway (NO)
University of Copenhagen
Denmark (DK)
LILLE 1 University - Science and Technology
France (FR)
Duke University
United States (USA) (US)
Germany (DE)
Universiteit Gent (UGent) / Ghent University
Belgium (BE)
University of Oslo
Norway (NO)
University of Copenhagen
Denmark (DK)
LILLE 1 University - Science and Technology
France (FR)
Duke University
United States (USA) (US)
How to cite
APA:
Amberg, C.E.A., Collart, T., Salenbien, W., Egger, L.M., Munnecke, A., Nielsen, A.T.,... Vandenbroucke, T.R. (2016). The nature of Ordovician limestone-marl alternations in the Oslo-Asker District (Norway): Witnesses of primary glacio-eustasy or diagenetic rhythms? Scientific Reports, 6. https://dx.doi.org/10.1038/srep18787
MLA:
Amberg, Chloé E. A., et al. "The nature of Ordovician limestone-marl alternations in the Oslo-Asker District (Norway): Witnesses of primary glacio-eustasy or diagenetic rhythms?" Scientific Reports 6 (2016).
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