D6 - San Ramon section (Paleocene of Argentina)

Where: Chubut, Argentina (42.7° S, 69.8° W: paleocoordinates 45.1° S, 58.8° W)

• coordinate estimated from map

When: Lefipán Formation, Danian (66.0 - 61.6 Ma)

• bed-level stratigraphic resolution

Environment/lithology: delta front; lithified mudstone

• During the early Danian coarsening-upward cycles reflect accumulation in tidal bars, mainly in a tide to waveinfluenced distal delta-front environment with high sedimentation rates. These deposits bear molluscan faunal associations indicative of recurrent changes from normal marine to low-salinity marine environments with low-oxygen, fine-grained, soupy substrates.
• This bed: Bioturbation - Heterolithic bedding

•The Lefipán Formation consists of marine to marginal marine, fossiliferous sandstones and mudstones with some intercalated coquinas and conglomerates.

Size class: microfossils

• Samples were marine (dinoflagellate cysts)and continental (spores, pollen grains, fungal remains, fresh water algae) palynomorphs.

Preservation: original sporopollenin

Collection methods: chemical,

• Slides are housed in the palynological collection of the Museo Paleontológico Egidio Feruglio, Trelew, Chubut, Argentina (MPEF-Palin)numbers 100 to 113.

Primary reference: V. D. Barreda, N. R. Cúneo, P. Wilf, E. D. Currano, R. A. Scasso and H. Brinkhuis. 2012. Cretaceous/Paleogene Floral Turnover in Patagonia: Drop in Diversity, Low Extinction, and a Classopollis Spike. PLoS ONE 7(12):e52455 [C. Jaramillo/J. Moreno]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 151458: authorized by Carlos Jaramillo, entered by Jessica Moreno on 03.10.2013

Creative Commons license: CC BY (attribution)

Taxonomic list

• Pollen terminology follows Punt et al. 2007.
Psilatricolpites inargutus Archangelsky 1973
 Pinales - Podocarpaceae
 Pinales - Araucariaceae
 Pinales - Cheirolepidiaceae
Classopollis sp. Pflug 1953
 Arecales -
Spinizonocolpites hialinus Archangelsky and Zamaloa 1986
Arecipites sp. Nichols et al. 1973
Trilites "sp. 2" Erdtman and Couper 1947
Trilites volkheimerii Filatoff 1975
Laevigatosporites ovatus Wilson and Webster 1946
Cyathidites minor Couper 1953
Cyathidites australis Couper 1953
Peromonolites vellosus Partridge 1973
 Gleicheniales - Gleicheniaceae
Deltoidospora sp. Miner 1935
  - Selaginellaceae
Ceratosporites equalis Cookson and Dettmann 1958
Senipites tercrassata Archangelsky 1973
Tricolporites "sp. 3" Cookson 1947
 Theales - Dilleniidae
Haloragacidites harrisii Mildenhall and Harris 1971
Rhoipites minusculus Archangelsky 1973
Gemmatricolpites "sp. 1" van Hoeken-Klinkenberg 1964
 Magnoliales - Chloranthaceae
Psilatricolporites salamanquensis Archangelsky and Zamaloa 1986
Rousea patagonica Archangelsky 1973
Retitricolporites "sp. 1" Van der Hammen and Wymstra 1964
 Gentianales - Apocynaceae
cf. Cricotriporites sp. Leidelmeyer 1966
cf. Cricotriporites
 Fabales - Fabaceae
Margocolporites sp. Ramanajuan 1966
 Malvales - Bombacaceae
 Proteales -
Triatriopollenites bertelsii Archangelsky 1973
Triatriopollenites lateflexus Archangelsky 1973
 Proteales - Proteaceae
Propylipollis cf. tenuiexinus Dettmann and Jarzen 1996
Echitriporites sp. Van der Hammen 1956
Lewalanipollis senectus Dettmann and Jarzen 1996
 Proteales -
Peninsulapollis gillii Dettmann and Jarzen 1988
Peninsulapollis cf. truswelliae Dettmann and Jarzen 1988
Proteacidites "sp. C" Cookson and Couper 1953
 Fagales -
Nothofagidites "sp. 1" Potonié 1960
Nothofagidites fuegiensis Menéndez and Caccavari 1975
Tricolpites "sp. 1" Potonié 1960
Striatricolporites gamerroi Archangelsky 1973