Fossil woods from cape Wiman (Paleocene) seymour (Marambio) island, Antartica.

PUJANA, ROBERTO R.; MIRABELLI, SEBASTIAN L.; MARENSSI, SERGIO A.; SANTILLANA, SERGIO N.

Salvador de Bahia

Congreso; XIV International Palynological Congress, X International Organisation of Palaeobotany Conference; 2016

p { margin-bottom: 0.25cm; direction: ltr; color: rgb(0, 0, 0); line-height: 120%; }p.western { font-family: "Liberation Serif","Times New Roman",serif; font-size: 12pt; }p.cjk { font-family: "Droid Sans Fallback"; font-size: 12pt; }p.ctl { font-family: "FreeSans"; font-size: 12pt; }Fossil woods from CapeWiman (Paleocene), Seymour (Marambio) Island, AntarcticaRoberto R. Pujana1,Sebastián L. Mirabelli2,Sergio A. Marenssi3,Sergio N. Santillana41MuseoArgentino de Ciencias Naturales-CONICET, Argentina,rpujana@macn.gov.ar2MuseoArgentino de Ciencias Naturales-CONICET, Argentina2Institutode Geociencias Básicas-CONICET, Argentina2InstitutoAntártico Argentino, ArgentinaFossilwoods collected at the locality of Cape Wiman, in the northeasternpart of the Seymour (Marambio) Island were anatomically studied indetail. The fossil wood bearing sediments of Paleocene age, wereformerly considered a stratigraphic unit (Wiman Formation) butaccording to more recent studies, these strata are part of the CrossValley Formation. The collection consists of more than 40 samples.All the samples are charcoaled and permineralized with carbonates andpreservation is often poor. Samples were thin sectioned and observedat SEM. The assemblage is dominated by conifers. Among the conifers,about half of the woods are assigned to the Araucariaceae(Agathoxylonspp.), accompanied by Podocarpaceae (Phyllocladoxylonand probable Podocarpoxylon).Angiosperms are not very well preserved, but the samples apparentlycorrespond to the same taxonomic unit, probably Eucryphiaceoxyloneucryphioides,which has scalariform perforation plates, mostly uniseriate rays andpredominantly solitary small vessels. Diversity of the fossil woodsis similar to previous studies of the Cross Valley Formation found inother localities of the same island. These composition reinforces thehypothesis that the Paleocene forest canopy were dominated by theAraucariaceae in the area and were later replaced by thePodocarpaceae in the Eocene (La Meseta Formation).Keywords:Wood anatomy, Western Antarctica, Cross Valley Formation.