Calcareous nannofossils of the Boreal Lower Cretaceous: Applications in biostratigraphy and palaeoceanography
The marine Lower Cretaceous sediments of northern, Boreal latitudes yield diverse and well-preserved calcareous nannofossil assemblages. The calcareous nannofloras of nine core and outcrop sections (of Ryazanian-Albian age) in England, Germany, the North Sea, and Barents Sea, are examined in detail...
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UCL (University College London)
1994
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Online Access: | https://discovery.ucl.ac.uk/id/eprint/10108862/1/Calcareous_nannofossils_of_the.pdf https://discovery.ucl.ac.uk/id/eprint/10108862/ |
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ftucl:oai:eprints.ucl.ac.uk.OAI2:10108862 2023-12-24T10:15:21+01:00 Calcareous nannofossils of the Boreal Lower Cretaceous: Applications in biostratigraphy and palaeoceanography Rutledge, David Charles 1994 text https://discovery.ucl.ac.uk/id/eprint/10108862/1/Calcareous_nannofossils_of_the.pdf https://discovery.ucl.ac.uk/id/eprint/10108862/ eng eng UCL (University College London) https://discovery.ucl.ac.uk/id/eprint/10108862/1/Calcareous_nannofossils_of_the.pdf https://discovery.ucl.ac.uk/id/eprint/10108862/ open Doctoral thesis, UCL (University College London). Thesis Doctoral 1994 ftucl 2023-11-27T13:07:33Z The marine Lower Cretaceous sediments of northern, Boreal latitudes yield diverse and well-preserved calcareous nannofossil assemblages. The calcareous nannofloras of nine core and outcrop sections (of Ryazanian-Albian age) in England, Germany, the North Sea, and Barents Sea, are examined in detail (utilising 773 samples). Dense sampling of key outcrop sections (in particular, Speeton) enables calibration of the observed nannofossil events against ammonite zones. The Barents Sea sections, which are shown to be highly condensed, yield the northernmost Lower Cretaceous nannofossils to be described. The previously chaotic taxonomy of Lower Cretaceous nannofossils is revised, and a major rationalisation of genera proposed - this involves several generic emendations, and twenty five new combinations. Two new genera, Apertasphaera and Neoparhabdolithus, and nine new species are described - Apertasphaera jakubowskii, Calculites burnettiae, Clepsilithus maculosus, Cyclagelosphaera papilla, Nannoconus inornatus, Nannoconus pseudoseptentrionalis, Rucinolithus windleyae, Tegumentum bergeni and Tubodiscus parvus. In addition, one new subspecies - Rhagodiscus angustus parvus - is described, and a number of species are split into informal varieties, to avoid biostratigraphical ambiguity. Following these revisions, the suprageneric classification is reappraised, and a new family - Family Tubodiscaceae - is proposed. An updated nannofossil zonation scheme for the Ryazanian to Aptian of the Boreal area is presented; this comprises twenty two zones (labelled BCl to BC22, in ascending order), and a number of additional subzones. Biostratigraphical resolution in the Hauterivian- Barremian is comparable with current ammonite zonations, and enables detailed sequence stratigraphical interpretation. Following the publication of new data from Tethyan sections (Bergen, 1994), the potential for direct inter-regional correlation is investigated; the nannofossil datums utilised generally support traditional, ammonite-based correlations but ... Doctoral or Postdoctoral Thesis Barents Sea University College London: UCL Discovery Barents Sea Bergen |
institution |
Open Polar |
collection |
University College London: UCL Discovery |
op_collection_id |
ftucl |
language |
English |
description |
The marine Lower Cretaceous sediments of northern, Boreal latitudes yield diverse and well-preserved calcareous nannofossil assemblages. The calcareous nannofloras of nine core and outcrop sections (of Ryazanian-Albian age) in England, Germany, the North Sea, and Barents Sea, are examined in detail (utilising 773 samples). Dense sampling of key outcrop sections (in particular, Speeton) enables calibration of the observed nannofossil events against ammonite zones. The Barents Sea sections, which are shown to be highly condensed, yield the northernmost Lower Cretaceous nannofossils to be described. The previously chaotic taxonomy of Lower Cretaceous nannofossils is revised, and a major rationalisation of genera proposed - this involves several generic emendations, and twenty five new combinations. Two new genera, Apertasphaera and Neoparhabdolithus, and nine new species are described - Apertasphaera jakubowskii, Calculites burnettiae, Clepsilithus maculosus, Cyclagelosphaera papilla, Nannoconus inornatus, Nannoconus pseudoseptentrionalis, Rucinolithus windleyae, Tegumentum bergeni and Tubodiscus parvus. In addition, one new subspecies - Rhagodiscus angustus parvus - is described, and a number of species are split into informal varieties, to avoid biostratigraphical ambiguity. Following these revisions, the suprageneric classification is reappraised, and a new family - Family Tubodiscaceae - is proposed. An updated nannofossil zonation scheme for the Ryazanian to Aptian of the Boreal area is presented; this comprises twenty two zones (labelled BCl to BC22, in ascending order), and a number of additional subzones. Biostratigraphical resolution in the Hauterivian- Barremian is comparable with current ammonite zonations, and enables detailed sequence stratigraphical interpretation. Following the publication of new data from Tethyan sections (Bergen, 1994), the potential for direct inter-regional correlation is investigated; the nannofossil datums utilised generally support traditional, ammonite-based correlations but ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Rutledge, David Charles |
spellingShingle |
Rutledge, David Charles Calcareous nannofossils of the Boreal Lower Cretaceous: Applications in biostratigraphy and palaeoceanography |
author_facet |
Rutledge, David Charles |
author_sort |
Rutledge, David Charles |
title |
Calcareous nannofossils of the Boreal Lower Cretaceous: Applications in biostratigraphy and palaeoceanography |
title_short |
Calcareous nannofossils of the Boreal Lower Cretaceous: Applications in biostratigraphy and palaeoceanography |
title_full |
Calcareous nannofossils of the Boreal Lower Cretaceous: Applications in biostratigraphy and palaeoceanography |
title_fullStr |
Calcareous nannofossils of the Boreal Lower Cretaceous: Applications in biostratigraphy and palaeoceanography |
title_full_unstemmed |
Calcareous nannofossils of the Boreal Lower Cretaceous: Applications in biostratigraphy and palaeoceanography |
title_sort |
calcareous nannofossils of the boreal lower cretaceous: applications in biostratigraphy and palaeoceanography |
publisher |
UCL (University College London) |
publishDate |
1994 |
url |
https://discovery.ucl.ac.uk/id/eprint/10108862/1/Calcareous_nannofossils_of_the.pdf https://discovery.ucl.ac.uk/id/eprint/10108862/ |
geographic |
Barents Sea Bergen |
geographic_facet |
Barents Sea Bergen |
genre |
Barents Sea |
genre_facet |
Barents Sea |
op_source |
Doctoral thesis, UCL (University College London). |
op_relation |
https://discovery.ucl.ac.uk/id/eprint/10108862/1/Calcareous_nannofossils_of_the.pdf https://discovery.ucl.ac.uk/id/eprint/10108862/ |
op_rights |
open |
_version_ |
1786202118615465984 |