Cullen Conifers: Early/Lower Miocene - Middle Miocene, Argentina

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Polypodiopsida - Polypodiaceae
Trichotomosulcites subgranulatus microspore Couper 1953
unclassified
Gymnospermae indet. microspore
replaced by Pinophyta
Coniferales - Podocarpaceae
Phyllocladidites elongatus microspore Zamaloa and Romero 2005
sp. nov.
Phyllocladidites mawsonii microspore Cookson 1947
Dacrycarpites australiensis microspore Cookson and Pike 1953
Lygistepollenites florinii microspore Stover and Evans 1973
Podocarpidites sp. microspore Cookson 1947
Podocarpidites torquatus microspore Mildenhall and Pocknall 1989
Podocarpidites rugulosus microspore Romero 1977
Podocarpidites microreticuloidatus microspore (Cookson 1947)
original and current combination Podocarpidites microreticuloidata
Equisetopsida - Araucariaceae
Araucariacites australis microspore Cookson 1947
see common names

Geography
Country:Argentina State/province:Tierra del Fuego County:Isla Grande
Coordinates: 53.0° South, 68.7° West (view map)
Paleocoordinates:53.6° South, 62.8° West
Basis of coordinate:estimated from map
Geographic resolution:local area
Time
Period:Neogene Epoch:Miocene
10 m.y. bin:Cenozoic 5
Key time interval:Early/Lower Miocene - Middle Miocene
Age range of interval:23.03000 - 11.63000 m.y. ago
Stratigraphy
Formation:Cullen
Stratigraphic resolution:formation
Stratigraphy comments: The Cullen Formation outcrops on the NE coast of Isla Grande de Tierra del Fuego and its age has been controversial for a long time; a probably early or middle Miocene age was proposed (Zamaloa, 1999).

Details of the geographical location of outcrops, the stratigraphic column and geological sections were published in this journal, dealing with spores of the same Formation (Zamaloa, 2004).

Samples were obtained from Hito I, Beta Dell and Tapera Sur Dell sections (Zamaloa, 2004)
Lithology and environment
Primary lithology:paleosol/pedogenic,green,yellow silty,sandy siltstone
Secondary lithology:fine,medium,brown sandstone
Lithology description: The Cullen Formation is composed of predominantly yellowish and greenish siltstone and claystone intercalated with fine to medium- grained brown sandstone. Fine-grained deposits formed in flood (alluvial) plains are prevalent in the Cullen Formation sequence. They include well-developed bioturbated paleosols showing pedogenesis. Plant remains consisting of fragments of roots, stems, leaves, and logs, are frequent. Coarser-grained sandy strata represent a channel fill facies.
Environment:"channel"
Geology comments: The statigraphical, sedimentological and taphonomical analyses indicate a paleoenvironment resulting from a system of meandering streams. The diverse and abundant spore assemblage reinforces the proposed paleoenvironment indicated by pollen assemblage and stratigraphy,consisting of humid temperate forests and local occurrences of bog, freshwater and near-shore lake communities.
Taphonomy
Modes of preservation:original sporopollenin
Size of fossils:microfossils
Collection methods and comments
Collection methods:chemical
Reason for describing collection:paleoecologic analysis
Collection method comments: Standard palynological techniques were used to prepare the samples. Microscopic slides were mounted in glycerine jelly and stained with safranin. Slides and residues are archived in the palynological collection of the Departamento de Ecologia, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, as BAFCB p.m.
Taxonomic list comments:Eleven conifer pollen taxa including one new species are recorded, as well as indeterminate gymnosperm pollen. Podocarpidites torquatus is recorded for the first time from South America.
Metadata
Database number:169382
Authorizer:C. Jaramillo Enterer:C. Jaramillo
Modifier:C. Jaramillo Research group:micropaleontology
Created:2015-05-22 15:13:59 Last modified:2015-05-22 15:18:36
Access level:the public Released:2015-05-22 15:13:59
Creative Commons license:CC BY
Reference information

Primary reference:
55276.fossil record M. C. Zamaloa and E. J. Romero. 2005. Neogene palynology of Tierra del Fuego, Argentina: conifers. Alcheringa (29)113-121 [C. Jaramillo/C. Jaramillo/C. Jaramillo]