CICYTTP   12500
CENTRO DE INVESTIGACION CIENTIFICA Y DE TRANSFERENCIA TECNOLOGICA A LA PRODUCCION
Unidad Ejecutora - UE
capítulos de libros
Título:
Phytolith studies in Gran Barranca (Central Patagonia, Argentina).
Autor/es:
ZUCOL, A. F. ET AL
Libro:
The Paleontology of Gran Barranca: Evolution and Environmental Change through the Middle Cenozoic of Patagonia.
Editorial:
Cambridge University Press
Referencias:
Año: 2007; p. 1 - 58
Resumen:
Zucol, A. F. (with the collaboration of Brea, M., Raigemborn M.S., Matheos S. Carlini, A.A., Madden, R.H. & G. Vucetich).
The sedimentary sequence of the southern escarpment of Lake Colhué Huapí (Gran
Barranca locality, Chubut province, Argentina) is composed of Sarmiento Formation, Río
Chico Group and Salamanca Formation. In the type profile (MMZ profile), the Sarmiento
Formation comprises three successive stratigraphic units: Gran Barranca, Puesto Almendra
and Colhué Huapí members, while Río Chico Group in the eastern extreme of the Gran
Barranca (BCH profile) presents only two of its formations (Las Flores and Koluél Kaike
formations). The sediments of this sequence, assigned by different indicators to the Eocene,
were analyzed in their phytoliths content. The previous stages and the current state of
phytolith analysis of this fossiliferous locality are summarized, with a preliminary analysis
of MMZ profile. Phytolith analysis of the Río Chico Group formations (BCH profile) and
Gran Barranca Member of Sarmiento Formation (MMZ profile) were implemented with
satisfactory results regarding both their fertility and their variability. These results have
allowed to establish a zonification of the sequence characterized by the presence of
different structural features of their paleocommunities. The presence of botanical groups in
each zone and their paleoenvironmental conditions are described. The oldest evidence of
megathermic paleograsslands is reported for South American paleobotanical records.