PALEOECOLOGÍA DE MICROSECUENCIAS PLANTÍFERAS DEL GRUPO RÍO GENOA, PÉRMICO DE CHUBUT, ARGENTINA

Rubén Cuneo

Abstract


PALAEOECOLOGY OF PLANTIFEROUS MICROSECUENCES OF THE RíO GENOA GROUP, PERMIAN OF CHUBUT, ARGENTINA. - One stratigraphical section was measured at Estancia La Casilda, Chubut Province, and 10 plantiferous sections (PS) were recognized. Quantitative palaeoecological data from four sedimentary microsequences bearing PS are statistically analyzed PS I, II and V occur in the Piedra Shotel Formation and PS VIII in the overlying Nueva Lubecka Formation, both of the Río Genoa Group. PS I, II and V probably developed in a fluvial floodplaín colonized by conifers, glossopterids and cordaitales. Restricted subenvironments were dominated by sphenophylls and arborescent lycopods, Ferns are usually present as secondary elements. PS VIII was also deposited in a fluvial environment, although in this case the floodplain reached the sea. Hígh humidity environmental conclitions are infered from the petrographical analysis of coals. The age of the sequence is considered to be early Permian (Lubeckense A) with typical species of the Glossopteris flora and mixed northern elements. Intercalated marine beds with invertebrates of the Cancrinella Zone also suggest a Permian age.

Full Text:

 Subscribers Only