West Point Layer C (Miocene to of South Atlantic)

Where: Falkland Islands, South Atlantic (51.4° S, 60.7° W: paleocoordinates 51.5° S, 57.3° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Middle Miocene to Middle Miocene (16.0 - 3.6 Ma)

• The preferred Middle? Miocene to Early Pliocene age limits are based on presence of the (now) mesotherm to typically megatherm genera Araucaria, Hedyosmum and Ovidia in a type of evergreen rainforest (podocarp-Nothofagus tall closed forest sensu Specht, 1970) that is now confined to relatively cool and uniformly wet climates in southern South America, New Zealand and Tasmania.

•Halle (1911: 210−211) subdivided the Forest Bed into two units (layers) based on texture and organic content: Layer C and Layer D.

Environment/lithology: mire or swamp; lithified, massive, yellow claystone

• Quantitative analyses of lignites from the Bass and Gippsland Basins and Southeastern Highlands in southeast Australia indicate that another commonly occurring gymnosperm in the Forest Bed (Podosporites microsaccatus) was common in heath and some coastal freshwater swamps, and in analogous upland environments during the Tertiary (Tulip et al., 1982; Macphail et al., 1994, M.K. Macphail and A.D. Partridge unpubl. data).
• Layer c, comprising a stone-free massive yellow clay with thin organic laminae (stringers).

•The Forest Bed is sandwiched between Quaternary clays and the Palaeozoic bedrock at the rear of West Point Harbour. No equivalent deposit of densely packed tree remains in an organic mud matrix has been found anywhere else in the Falklands, suggesting that accumulation and long-term preservation of the deposit are the result of highly unusual circumstances. These almost certainly include topographic factors, for exam- ple the bay is encircled by steep hills, and the protection afforded to the wood-rich stratum by the overlying stony solifluction clays.

Size class: microfossils

Preservation: original sporopollenin

Collected in 1996 and 1997

Collection methods: chemical, hydroflouric,

• Samples collected in 1996 and 1907 represent Halle's Layers c and d, respectively.

•Slides from Halle's original collection are housed at the Swedish Museum of Natural History (Stockholm).

Primary reference: M. Macphail and D. J. Cantrill. 2006. Age and implications of the Forest Bed, Falkland Islands, southwest Atlantic Ocean: Evidence from fossil pollen and spores. Palaeogeography, Palaeoclimatology, Palaeoecology (240)602-629 [C. Jaramillo/C. Jaramillo]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 169355: authorized by Carlos Jaramillo, entered by Carlos Jaramillo on 20.05.2015

Creative Commons license: CC BY (attribution)

Taxonomic list

unclassified
  -
Chlorophyceae
  -
Botryococcus braunii Kutzing 1849
Pinopsida
 Pinales - Podocarpaceae
 Pinales - Araucariaceae
 Pinales - Taxodiaceae
Cupressacites indet. Bolkhovitina 1956
Monocotyledoneae
 Arecales - Arecaceae
  -
 Liliales - Liliidae
Monocots
 Poales - Poaceae
Graminidites sp. Potonie 1960
Pteridopsida
  -
 Gleicheniales - Matoniaceae
Dictyophyllidites cf. arcuatus Pocknall and Mildenhall 1984
 Polypodiales -
Polypodiisporites radiatus Pocknall and Mildenhall 1984
Polypodiisporites inangahuensis Pocknall and Mildenhall 1984
  -
Lycopsida
  -
Magnoliopsida
  -
Dicotyledonae
 Polygonales - Caryophyllidae
Polycolporopollenites esobalteus Pocknall and Mildenhall 1984
Magnoliopsida
  -
Rhoipites "sp. A" Wodehouse 1933
 Canellales -
 Myrtales -
 Santalales - Loranthaceae
 Proteales -
Proteacidites reticuloscabratus
P. (Propylipollis) reticuloscabratus
Proteacidites "sp. A" Cookson and Couper 1953
Proteacidites "sp. B" Cookson and Couper 1953
 Fagales -
Nothofagidites saraensis Menendez and Caccavari 1975
Nothofagidites cf. acromegacanthus Menendez and Caccavari 1975
  -
Canthiumidites bellus
  -
Canthiumidites cf. bellus Mildenhall and Pocknall 1989
Pinidae
 Cupressales - Pinidae
Inaperturopollenites sp. PotoniƩ 1966
Compositoipollenites
  -
Quintiniapollis
  -
Quintiniapollis sp. Mildenhall and Pocknall 1989