Cambro-Ordovician microorganisms: acritarchs and endoliths
Organic-walled microfossils are abundant and taxonomically diverse in Cambrian-Ordovician strata; some are important for biostratigraphy and for the correlation of geological successions. New assemblages of Cambrian-Ordovician acritarchs from Kolguev Island, Arctic Russia and Middle Cambrian ichnofo...
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Uppsala universitet, Institutionen för geovetenskaper
2005
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ftuppsalauniv:oai:DiVA.org:uu-5726 2023-05-15T15:12:59+02:00 Cambro-Ordovician microorganisms: acritarchs and endoliths Stockfors, Martin 2005 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-5726 eng eng Uppsala universitet, Institutionen för geovetenskaper Uppsala : Institutionen för geovetenskaper http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-5726 urn:isbn:91-506-1798-2 info:eu-repo/semantics/openAccess Earth sciences Cambrian Ordovician acritarch endolith Kolguev Island North Greenland Stratigraphy Geovetenskap Doctoral thesis, comprehensive summary info:eu-repo/semantics/doctoralThesis text 2005 ftuppsalauniv 2023-02-23T21:44:36Z Organic-walled microfossils are abundant and taxonomically diverse in Cambrian-Ordovician strata; some are important for biostratigraphy and for the correlation of geological successions. New assemblages of Cambrian-Ordovician acritarchs from Kolguev Island, Arctic Russia and Middle Cambrian ichnofossils of endoliths from Peary Land, North Greenland are studied. Twenty-seven acritarch species are described in detail and 10 taxa are left under open nomenclature. The diagnosis of one genus is restricted, and two other are emended. New combinations are proposed for three species and one new species is recognised. The studied acritarch assemblages are taxonomically rich and age-diagnostic and used to recognise Upper Cambrian and Tremadoc strata on Kolguev Island. The sedimentologically continuous successions provide for the first time palaeontological evidence of Cambrian strata in the north-eastern sector of Europe. The exact level of the Cambrian-Ordovician boundary was distinguished together with stratigraphic intervals equivalent to the Peltura and Acerocare zones of the Upper Cambrian of Baltica. The newly established relative age of the lowermost sedimentary succession overlying the Timanian unconformity allows verification of the minimum age of the Timanian deformation and the time-span of the hiatus bound to this unconformity. Endoliths occur in the fossil record from the Early Archean and they played an important role in the formation of stromatolites and the process of bioerosion and biodegradation. Endoliths that have actively bored into brachiopod shells or carbonate grains (euendoliths), and some that inhabited the cavities inside brachiopod shells (cryptoendoliths) are described. Borings within the carbonate grains extended with a dentritic pattern, whereas those within the brachiopod shells were formed by a multifilamentous euendolith which produced characteristic longitudinally ridged galleries. The cryptoendolithic morphologies include indeterminate coccoid masses and at least two filamentous forms. ... Doctoral or Postdoctoral Thesis Arctic Greenland Kolguev North Greenland Peary Land Uppsala University: Publications (DiVA) Arctic Greenland Peary ENVELOPE(-63.867,-63.867,-65.250,-65.250) Peary Land ENVELOPE(-32.500,-32.500,82.633,82.633) |
institution |
Open Polar |
collection |
Uppsala University: Publications (DiVA) |
op_collection_id |
ftuppsalauniv |
language |
English |
topic |
Earth sciences Cambrian Ordovician acritarch endolith Kolguev Island North Greenland Stratigraphy Geovetenskap |
spellingShingle |
Earth sciences Cambrian Ordovician acritarch endolith Kolguev Island North Greenland Stratigraphy Geovetenskap Stockfors, Martin Cambro-Ordovician microorganisms: acritarchs and endoliths |
topic_facet |
Earth sciences Cambrian Ordovician acritarch endolith Kolguev Island North Greenland Stratigraphy Geovetenskap |
description |
Organic-walled microfossils are abundant and taxonomically diverse in Cambrian-Ordovician strata; some are important for biostratigraphy and for the correlation of geological successions. New assemblages of Cambrian-Ordovician acritarchs from Kolguev Island, Arctic Russia and Middle Cambrian ichnofossils of endoliths from Peary Land, North Greenland are studied. Twenty-seven acritarch species are described in detail and 10 taxa are left under open nomenclature. The diagnosis of one genus is restricted, and two other are emended. New combinations are proposed for three species and one new species is recognised. The studied acritarch assemblages are taxonomically rich and age-diagnostic and used to recognise Upper Cambrian and Tremadoc strata on Kolguev Island. The sedimentologically continuous successions provide for the first time palaeontological evidence of Cambrian strata in the north-eastern sector of Europe. The exact level of the Cambrian-Ordovician boundary was distinguished together with stratigraphic intervals equivalent to the Peltura and Acerocare zones of the Upper Cambrian of Baltica. The newly established relative age of the lowermost sedimentary succession overlying the Timanian unconformity allows verification of the minimum age of the Timanian deformation and the time-span of the hiatus bound to this unconformity. Endoliths occur in the fossil record from the Early Archean and they played an important role in the formation of stromatolites and the process of bioerosion and biodegradation. Endoliths that have actively bored into brachiopod shells or carbonate grains (euendoliths), and some that inhabited the cavities inside brachiopod shells (cryptoendoliths) are described. Borings within the carbonate grains extended with a dentritic pattern, whereas those within the brachiopod shells were formed by a multifilamentous euendolith which produced characteristic longitudinally ridged galleries. The cryptoendolithic morphologies include indeterminate coccoid masses and at least two filamentous forms. ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Stockfors, Martin |
author_facet |
Stockfors, Martin |
author_sort |
Stockfors, Martin |
title |
Cambro-Ordovician microorganisms: acritarchs and endoliths |
title_short |
Cambro-Ordovician microorganisms: acritarchs and endoliths |
title_full |
Cambro-Ordovician microorganisms: acritarchs and endoliths |
title_fullStr |
Cambro-Ordovician microorganisms: acritarchs and endoliths |
title_full_unstemmed |
Cambro-Ordovician microorganisms: acritarchs and endoliths |
title_sort |
cambro-ordovician microorganisms: acritarchs and endoliths |
publisher |
Uppsala universitet, Institutionen för geovetenskaper |
publishDate |
2005 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-5726 |
long_lat |
ENVELOPE(-63.867,-63.867,-65.250,-65.250) ENVELOPE(-32.500,-32.500,82.633,82.633) |
geographic |
Arctic Greenland Peary Peary Land |
geographic_facet |
Arctic Greenland Peary Peary Land |
genre |
Arctic Greenland Kolguev North Greenland Peary Land |
genre_facet |
Arctic Greenland Kolguev North Greenland Peary Land |
op_relation |
http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-5726 urn:isbn:91-506-1798-2 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766343595994906624 |