A marginal marine ichnofauna from the Blaiklock Glacier Group (?Lower Ordovician) of the Shackleton Range, Antarctica
ABSTRACT A diverse arthropod-dominated ichnofauna, associated with a poorly preserved crustacean fauna and soft-bodied ?medusoid impressions, is described from the Blaiklock Glacier Group of the north-western Shackleton Range (Coats Land), Antarctica. The ichnofauna consists of Asaphoidichnus, Beaco...
Published in: | Transactions of the Royal Society of Edinburgh: Earth Sciences |
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crcambridgeupr:10.1017/s026359330000050x 2024-03-03T08:37:58+00:00 A marginal marine ichnofauna from the Blaiklock Glacier Group (?Lower Ordovician) of the Shackleton Range, Antarctica Weber, B. Braddy, S. J. 2003 http://dx.doi.org/10.1017/s026359330000050x https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S026359330000050X en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Transactions of the Royal Society of Edinburgh: Earth Sciences volume 94, issue 1, page 1-20 ISSN 0263-5933 1473-7116 Paleontology Earth and Planetary Sciences (miscellaneous) journal-article 2003 crcambridgeupr https://doi.org/10.1017/s026359330000050x 2024-02-08T08:34:59Z ABSTRACT A diverse arthropod-dominated ichnofauna, associated with a poorly preserved crustacean fauna and soft-bodied ?medusoid impressions, is described from the Blaiklock Glacier Group of the north-western Shackleton Range (Coats Land), Antarctica. The ichnofauna consists of Asaphoidichnus, Beaconites, Didymaulichnus, Diplichnites, Gordia, ?Laevicyclus, Merostomichnites, Monomorphichnus, Palaeophycus, Planolites, Rusophycus, Selenichnites , and Taphrhelminthoides (ichnogen nov.). Three new ichnotaxa are recognised: Taphrhelminthoides antarcticus n. ichnogen. et ichnosp. is a bilobate trail, composed of two parallel flat lobes, separated by a median ridge with a characteristic figure-of-eight pattern. Merostomichnites gracilis n. ichnosp. is characterised by its proportions (external:internal width ratio >3) and series of 10 to 12, thin, linear tracks. Selenichnites antarcticus n. ichnosp. is characterised by small elongate horseshoe-shaped marks, the medial portion showing three to five transverse scratch-marks. The palaeoenvironment is interpreted as extremely shallow marine water, possibly a tide-dominated estuary, based on sedimentological evidence and the composition of the ichnofauna. Radiometric and palaeomagnetic data indicate that this assemblage is Lower Ordovician in age, representing the first autochthonous Ordovician fossiliferous succession to be described from Antarctica. The succession shows several sedimentological and palaeontological similarities with the basal units of the Ordovician Table Mountain Group in South Africa, supporting palaeogeographic models placing the Palaeozoic Blaiklock basin close to the Ordovician Table Mountain basin. Article in Journal/Newspaper Antarc* Antarctica antarcticus Cambridge University Press Shackleton Shackleton Range ENVELOPE(-26.000,-26.000,-80.833,-80.833) Coats Land ENVELOPE(-27.500,-27.500,-77.000,-77.000) Table Mountain ENVELOPE(69.031,69.031,-48.668,-48.668) Median Ridge ENVELOPE(-62.833,-62.833,-64.983,-64.983) Blaiklock ENVELOPE(-67.019,-67.019,-67.545,-67.545) Blaiklock Glacier ENVELOPE(-29.666,-29.666,-80.583,-80.583) Transactions of the Royal Society of Edinburgh: Earth Sciences 94 1 1 20 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Paleontology Earth and Planetary Sciences (miscellaneous) |
spellingShingle |
Paleontology Earth and Planetary Sciences (miscellaneous) Weber, B. Braddy, S. J. A marginal marine ichnofauna from the Blaiklock Glacier Group (?Lower Ordovician) of the Shackleton Range, Antarctica |
topic_facet |
Paleontology Earth and Planetary Sciences (miscellaneous) |
description |
ABSTRACT A diverse arthropod-dominated ichnofauna, associated with a poorly preserved crustacean fauna and soft-bodied ?medusoid impressions, is described from the Blaiklock Glacier Group of the north-western Shackleton Range (Coats Land), Antarctica. The ichnofauna consists of Asaphoidichnus, Beaconites, Didymaulichnus, Diplichnites, Gordia, ?Laevicyclus, Merostomichnites, Monomorphichnus, Palaeophycus, Planolites, Rusophycus, Selenichnites , and Taphrhelminthoides (ichnogen nov.). Three new ichnotaxa are recognised: Taphrhelminthoides antarcticus n. ichnogen. et ichnosp. is a bilobate trail, composed of two parallel flat lobes, separated by a median ridge with a characteristic figure-of-eight pattern. Merostomichnites gracilis n. ichnosp. is characterised by its proportions (external:internal width ratio >3) and series of 10 to 12, thin, linear tracks. Selenichnites antarcticus n. ichnosp. is characterised by small elongate horseshoe-shaped marks, the medial portion showing three to five transverse scratch-marks. The palaeoenvironment is interpreted as extremely shallow marine water, possibly a tide-dominated estuary, based on sedimentological evidence and the composition of the ichnofauna. Radiometric and palaeomagnetic data indicate that this assemblage is Lower Ordovician in age, representing the first autochthonous Ordovician fossiliferous succession to be described from Antarctica. The succession shows several sedimentological and palaeontological similarities with the basal units of the Ordovician Table Mountain Group in South Africa, supporting palaeogeographic models placing the Palaeozoic Blaiklock basin close to the Ordovician Table Mountain basin. |
format |
Article in Journal/Newspaper |
author |
Weber, B. Braddy, S. J. |
author_facet |
Weber, B. Braddy, S. J. |
author_sort |
Weber, B. |
title |
A marginal marine ichnofauna from the Blaiklock Glacier Group (?Lower Ordovician) of the Shackleton Range, Antarctica |
title_short |
A marginal marine ichnofauna from the Blaiklock Glacier Group (?Lower Ordovician) of the Shackleton Range, Antarctica |
title_full |
A marginal marine ichnofauna from the Blaiklock Glacier Group (?Lower Ordovician) of the Shackleton Range, Antarctica |
title_fullStr |
A marginal marine ichnofauna from the Blaiklock Glacier Group (?Lower Ordovician) of the Shackleton Range, Antarctica |
title_full_unstemmed |
A marginal marine ichnofauna from the Blaiklock Glacier Group (?Lower Ordovician) of the Shackleton Range, Antarctica |
title_sort |
marginal marine ichnofauna from the blaiklock glacier group (?lower ordovician) of the shackleton range, antarctica |
publisher |
Cambridge University Press (CUP) |
publishDate |
2003 |
url |
http://dx.doi.org/10.1017/s026359330000050x https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S026359330000050X |
long_lat |
ENVELOPE(-26.000,-26.000,-80.833,-80.833) ENVELOPE(-27.500,-27.500,-77.000,-77.000) ENVELOPE(69.031,69.031,-48.668,-48.668) ENVELOPE(-62.833,-62.833,-64.983,-64.983) ENVELOPE(-67.019,-67.019,-67.545,-67.545) ENVELOPE(-29.666,-29.666,-80.583,-80.583) |
geographic |
Shackleton Shackleton Range Coats Land Table Mountain Median Ridge Blaiklock Blaiklock Glacier |
geographic_facet |
Shackleton Shackleton Range Coats Land Table Mountain Median Ridge Blaiklock Blaiklock Glacier |
genre |
Antarc* Antarctica antarcticus |
genre_facet |
Antarc* Antarctica antarcticus |
op_source |
Transactions of the Royal Society of Edinburgh: Earth Sciences volume 94, issue 1, page 1-20 ISSN 0263-5933 1473-7116 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s026359330000050x |
container_title |
Transactions of the Royal Society of Edinburgh: Earth Sciences |
container_volume |
94 |
container_issue |
1 |
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1 |
op_container_end_page |
20 |
_version_ |
1792503135624757248 |