Seymour Island A7: Late/Upper Campanian - Maastrichtian, Antarctica
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
unclassified
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Graphelispora cf. evansii microspore
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Lycopodiopsida
- Lycopodiales
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Retitriletes austroclavatidites microspore
Döring et al. 1963
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Retitriletes cf. eminulus microspore
Srivastava 1975
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Lycopodiopsida
- Selaginellales
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Camarozonosporites ohaiensis microspore
Dettmann and Playford 1968
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Camarozonosporites ambigens microspore
Playford 1971
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Ceratosporites equalis microspore
Cookson and Dettmann 1958
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Bryopsida
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Stereisporites antiquasporites microspore
Dettmann 1963
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Stereisporites regium microspore
Drugg 1967
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Polypodiopsida
- Osmundaceae
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Baculatisporites comaumensis microspore
Potonie 1953
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Polypodiopsida
- Polypodiaceae
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Laevigatosporites ovatus microspore
Wilson and Webster 1946
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Laevigatosporites major microspore
Krutzsch 1959
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Polypodiopsida
- Gleicheniaceae
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Gleicheniidites circinidites microspore
Dettmann 1963
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Pteridopsida
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Cyathidites minor microspore
Couper 1953
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Cyathidites cf. minor microspore
Couper 1953
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Osmundacidites wellmanii microspore
Couper 1953
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see common names |
Geography
Country: | Antarctica | State/province: | Seymour Island |
Coordinates: | 64.3° South, 56.9° West (view map) | ||
Paleocoordinates: | 62.3° South, 67.7° West | ||
Basis of coordinate: | estimated from map | ||
Geographic resolution: | small collection |
Time
Period: | Cretaceous | Epoch: | Late/Upper Cretaceous |
Key time interval: | Late/Upper Campanian - Maastrichtian | ||
Age range of interval: | 83.60000 - 66.00000 m.y. ago |
Stratigraphy
Geological group: | Seymour Island | Formation: | López de Bertodano | ||
Local section: | A | Local bed: | 7 | ||
Local order: | bottom to top | ||||
Stratigraphic resolution: | formation | ||||
Stratigraphy comments: Section A7 have 140 - 150 m. The section contains 15 samples: 01-15.
The formation was subdivided into 10 lithologic units by Macellari (1984b, 1988). Units 1 to 9 (~1100 m thick) span the upper Campanian and Maastrichtian,and the uppermost Unit 10 (up to 90m thick) is Tertiary (Danian).The formation is disconformably overlain by deltaic sediments of the Paleocene Sobral Formation. |
Lithology and environment
Primary lithology: | silty,sandy not reported |
Lithology description: Seymour Island is a small (20km), seasonally ice-free island in the James Ross Island basin at the northeastern end of the Antarctic Peninsula. Upper Cretaceous strata on Seymour Island are placed in the López de Bertodano Formation (Rinaldi et al. 1978; Rinaldi 1982; Macellari 1984b, 1988), which is 1190m thick, richly fossiliferous, poorly consolidated, and composed predominantly of grey sandy silts. It includes mud-rich units in the lower part; some fine-grained, often calcareous, sandstone beds throughout the formation; and glauconite beds in the uppermost part. | |
Environment: | marginal marine indet. |
Geology comments: These sediments were deposited in relatively low-energy, shallow shelf to marginal marine environments.
Although Mesozoic tectonic reconstructions of the Antarctic Peninsula- South America region are not universally accepted, it is generally agreed that the James Ross Island basin contains sedimentary and volcanic strata deposited in a back-arc terrain (e.g. Elliot 1988). |
Taphonomy
Modes of preservation: | original sporopollenin |
Size of fossils: | microfossils |
Collection methods and comments
Collection methods: | chemical,field collection |
Reason for describing collection: | paleoecologic analysis |
Museum repositories: | USNM |
Collection method comments: Spores from the Cretaceous part of the Lopez de Bertodano Formation discussed here are from a discontinuous section ( A5 through A11) collected during reconnaisance field-work in 1982, and section B1 collected in 1983/84. Another 12 samples from section A19 were examined. Samples were taken from holes dug about 10-30 cm into well-exposed outcrop, in part to avoid surficial slope wash. Surface weathering was not significantat most of these localities, although samples were collected from freshly exposed escarpments where possible.
Material will be housed in the National Museum of Natural History, Smithsonian Institution, Washington, D.C. | |
Taxonomic list comments:Recycled spores and pollen are common throughout the upper Campanian and Maastrichtian sediments of Seymour Island. They include rare Permian and Triassic species, recognizable by their diagnostic morphology. Some are of substantially darker color, but many of these Permian-Triassic specimens are surprisingly light-colored (yellow) and well-preserved, suggest- ing a history that included negligible thermal alteration (Askin and Elliot 1982). |
Metadata
Database number: | 167582 | ||
Authorizer: | C. Jaramillo | Enterer: | C. Jaramillo |
Modifier: | C. Jaramillo | Research group: | micropaleontology |
Created: | 2015-03-24 15:02:43 | Last modified: | 2015-03-24 15:40:37 |
Access level: | the public | Released: | 2015-03-24 15:02:43 |
Creative Commons license: | CC BY |
Reference information
Primary reference:
54654. | fossil record | R. A. Askin. 1990. Cryptogam spores from the upper Campanian and Maastrichtian of Seymour Island, Antarctica. Micropaleontology (36)141-156 [C. Jaramillo/C. Jaramillo] |