Triassic floras of Argentina: biostratigraphy, floristic events and comparison with other areas of Gondwana and Laurasia

MOREL, E.; ARTABE, A.; SPALLETTI, L.

ALCHERINGA

TAYLOR & FRANCIS LTD

Lugar: Londres; Año: 2003 vol. 27 p. 231 - 243

0311-5518

The Triassic Floras of Argentina: biostratigraphy, floristic events and comparison with other areas of Gondwana and Laurasia. The palaeofloristic record found in several stratigraphic units of southern and west ? central Argentina allows the recognition of five Assemblage Biozones and three Stages, defined on the basis of Assemblage Biozone chronology, analysis of main stratigraphic unconformities, and evolution of basin infill. From the chronological viewpoint, the Barrealian, Cortaderitian and Florian stages are characterised by three palaeofloristic events: a) appearance of mesophytic elements and coexistence of Palaeozoic and Mesozoic groups, b) maximum diversification of the Dicroidium Flora, and c) decline of the Dicroidium Flora and replacement by morphotypes with strong Jurassic affinity. The Triassic geological record of Argentina, notable for the remarkable continuity of fossil floras, has a great potential for long-distance correlations. Using the palaeofloristic events recognised in southwestern Gondwana, a global chart was made considering the bio and chronostratigraphic units, and their comparison with the Triassic palaeofloras distinguished in the Eastern Province of extratropical Gondwana and in Laurasia.