INFERENCIAS PALEOCLIMATICAS A PARTIR DEL ESTUDIO DE LOS ANILLOS DE CRECIMIENTO DE LEÑOS FOSILES DE LA FORMACION RIO TURBIO, SANTA CRUZ, ARGENTINA. I. NOTHOFAGOXYLON PARAPROCERA Ancibor, 1990

Abstract

PALEOCLIMATIC INFERENCES FOR THE RIO TURBIO FORMATION THROUGH THE STUDY OF GROWTH RINGS IN FOSSIL WOODS. I. NOTHOFAGOXYLON PARAPROCERA ANCIBOR, 1990. Dendrochronologic methods have been used to study fossil woods of Nothofagoxylon paraprocera Ancibor 1990, from the Rio Turbio Formation, Santa Cruz, province Argentina. Analyses of well preserved growth patterns have yielded information about growth periodicity. Increase annual growth is variable (0,45-3,53 mm). The values of medium sensibility are found to develop between normal limits; and the low correlation allows to suggest that the dendrochronologic features of these trees are similar to extant ones, growing near the fossiliferous locality of Rio Turbio. N. paraprocera lived under temperate, strongly seasonal, weather conditions. These conditions preveiled in the area during part of the Eocene, allowing the development of a community that occupied topographycally higher ecological niches.