IGEBA   23946
INSTITUTO DE GEOCIENCIAS BASICAS, APLICADAS Y AMBIENTALES DE BUENOS AIRES
Unidad Ejecutora - UE
artículos
Título:
A late Paleozoic fossil forest from the southern Andes, Argentina
Autor/es:
CÉSARI, S.N.; BUSQUETS, P.; MÉNDEZ-BEDIA, I.; COLOMBO, F.; LIMARINO, C.; CARDÓ, R.; GALLASTEGUI, G.
Revista:
Palaeogeography, Palaeoclimatology, Palaeoecology
Editorial:
ELSEVIER
Referencias:
Año: 2012 vol. 333 p. 131 - 147
ISSN:
0031-0182
Resumen:
An anatomical and ecological study of a Late Pennsylvanianearly Permian
assemblage of silicified trunks from the San Ignacio Formation of
southern Andean Cordillera is detailed. This stratigraphic unit has been
divided in three facies associations. The silicified trunks are
abundant in the middle part of the facies association C (limestones,
shales and volcanics) forming a persistent forested stratigraphic level.
Anatomical information integrated with sedimentological data, has
allowed reconstruction of a plant community that grew on the westernmost
margin of Gondwana. The paleoforest grew in wetland environments, where
a taphocoenosis of only permineralized trunks and stumps has been
preserved. Based on characters of the stem and roots the trees are
cordaitaleans, though distinct from other members of this group.
Vascular traces exhibit tracheids arranged in circular patterns
indicating auxin regulation of axial growth and probably the presence of
epicormic shoots. These fossil trees also preserve anatomical evidence
of plantarthropod interactions and rootlets invading the decaying wood.
Indistinct growth rings as well as additional indirect evidence
indicate that this ecosystem experienced an overall humid, warm climatic
regime.