%0 Journal Article
%T Darwin forest at agua de la zorra: the first in situ forest discovered in South America by Darwin in 1835 El Bosque Darwin en Agua de la Zorra: El primer bosque in situ descubierto en Am谷rica del Sur por Darwin en 1835
%A Mariana Brea
%A Anal赤a E. Artabe
%A Luis A. Spalletti
%J Revista de la Asociaci車n Geol車gica Argentina
%D 2009
%I Asociaci車n Geol車gica Argentina
%X The Agua de la Zorra area (near Uspallata, Mendoza, Argentina) is one of the best renowned fossil localities of the country because of its spectacular in situ fossil forest. This forest was discovered by Charles Darwin in 1835, who described this forest as monotypic and assigned it a Tertiary age. Nowadays, this fossil locality is known as the Darwin Forest. Over a century and a half later it was reinterpreted as a mixed Middle Triassic forest and a new fossil monotypic palaeocommunity of horsetails was discovered. This palaeovegetation is included in the Paramillo Formation (i.e., lower section the Potrerillos Formation) of northwestern Cuyo Basin, Mendoza province (69∼12' W and 32∼30' S). The sediments were deposited in a sinuous fluvial system, in which channel-filling sand bodies were associated with mud-dominated floodplain deposits. The palaeoforest grew on an andisol soil that developed on volcaniclastic floodplain deposits. It had a density of 427 -759 trees per hectare, and was constituted by conifers and corystosperms distributed in two arboreal strata. The highest reached 20-26 m tall, and was dominated by corystosperms, but it also included the tallest conifers. The second stratum, mainly composed of conifers, ranged between 16-20 m tall. The forest has also emergent corystosperms, which reached 30 m tall. The understorey was composed of ferns. Growth ring anatomy suggests that conifers could have had an evergreen habit. Structure of vegetation, growth ring analyses and sedimentation suggest that the forest developed under dry, subtropical, and strongly seasonal conditions. El 芍rea de Agua de la Zorra (cerca de Uspallata, Mendoza, Argentina) es uno de los sitios f車siles m芍s espectaculares y renombrados del pa赤s porque aflora un bosque in situ. Este bosque descripto como monot赤pico y asignado al Terciario fue descubierto por Charles Darwin en 1835. Un siglo y medio m芍s tarde, se reinterpret車 como un bosque mixto del Tri芍sico Medio y se reconoci車 una nueva paleocomunidad monot赤pica de esfen車fitas. La paleovegetaci車n proviene de la Formaci車n Paramillo (= secci車n inferior de la Formaci車n Potrerillos) de la regi車n noroeste de la Cuenca Cuyana, provincia de Mendoza (69∼12'O y 32∼30'S). Los sedimentos fueron depositados por un sistema fluvial de alta sinuosidad. El bosque f車sil creci車 sobre suelos del tipo andisol que se desarrollaron sobre dep車sitos de planicies volcanicl芍sticas. El bosque Darwin tiene una densidad de 427-759 芍rboles por hect芍rea. Este est芍 constituido por con赤feras y corystospermas y tiene dos estratos arb車reos. El m芍s alto se de
%K Paleovegetaci車n
%K Paleoecolog赤a
%K Paleoambientes
%K Tri芍sico Medio
%K Sudoeste de Gondwana
%K Palaeovegetation
%K Palaeoecology
%K Palaeoenvironments
%K Middle Triassic
%K Southwestern Gondwana
%U http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0004-48222009000100004