Seymour Island A9: Late/Upper Campanian - Maastrichtian, Antarctica

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Lycopodiopsida - Selaginellales
Ceratosporites equalis microspore Cookson and Dettmann 1958
Camarozonosporites ohaiensis microspore Dettmann and Playford 1968
Camarozonosporites ambigens microspore Playford 1971
Lycopodiopsida - Lycopodiales
Retitriletes austroclavatidites microspore Döring et al. 1963
Retitriletes nodosus microspore Srivastava 1975
Retitriletes cf. eminulus microspore Srivastava 1975
Lycopodiopsida - Isoetales - Isoetaceae
Echinosporis informal sp. 1 microspore Krutzsch 1967
Marchantiopsida - Marchantiidae
Triporoletes reticulatus microspore Playford 1971
Bryopsida
Stereisporites regium microspore Drugg 1967
Stereisporites antiquasporites microspore Dettmann 1963
Pteridopsida
Osmundacidites wellmanii microspore Couper 1953
Grapnelispora cf. evansii microspore Stover and Partridge 1984
Cyathidites sp. microspore Couper 1953
Cyathidites minor microspore Couper 1953
Cyathidites cf. minor microspore Couper 1953
Cyathidites australis microspore Couper 1953
Polypodiopsida - Polypodiaceae
Laevigatosporites ovatus microspore Wilson and Webster 1946
Laevigatosporites major microspore Krutzsch 1959
Polypodiopsida - Blechnaceae
Peromonolites bowenii microspore
Polypodiopsida - Osmundaceae
Baculatisporites comaumensis microspore Potonie 1953
Polypodiopsida - Gleicheniaceae
Gleicheniidites circinidites microspore Dettmann 1963
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:9
Local order:bottom to top
Stratigraphic resolution:formation
Stratigraphy comments: Section A9 have 140 - 150 m. The section contains 20 samples: 01-20.

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:167585
Authorizer:C. Jaramillo Enterer:C. Jaramillo
Research group:micropaleontology
Created:2015-03-24 16:06:25 Last modified:2015-03-24 16:06:25
Access level:the public Released:2015-03-24 16:06:25
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]