IANIGLA   20881
INSTITUTO ARGENTINO DE NIVOLOGIA, GLACIOLOGIA Y CIENCIAS AMBIENTALES
Unidad Ejecutora - UE
artículos
Título:
Icnofaunas triásicas en abanicos aluviales distales: evidencias de la Formación Cerro Puntudo, Cuenca Cuyana, Argentina.
Autor/es:
KRAPOVICKAS, VERÓNICA; MÁNGANO, MARÍA GABRIELA; MANCUSO, ADRIANA CECILIA; MARSICANO, CLAUDIA; VOLKHEIMER, WOLFGANG
Revista:
AMEGHINIANA
Editorial:
Asociación Paleontológica Argentina
Referencias:
Año: 2008 vol. 45 p. 429 - 429
ISSN:
0002-7014
Resumen:
Abstract: Triassic ichnofaunas in distal alluvial fans: evidence from the Cerro PuntudoFormation, Cuyo Basin, Argentina.nmAlluvial fan deposits of the Cerro Puntudo Formation (Triassic, Cuyo Basin, San Juanprovince) contain a low-diversity ichnofauna. The analyzed section recordssedimentation in the most distal portion of an alluvial fan system. Palaeophycustubularis Hall, Palaeophycus striatus Hall, and small sub-horizontal and inclined tracefossils occur in laterally extensive tuffaceous limestone, interpreted as playa-lakedeposits originated by flash floods. They are attributed to the Scoyenia ichnofacies.Massive and trough cross-stratified medium- and fine-grained sandstone, filling smallchannelized bodies, hosts a monospecific association of sparse Skolithos isp. illustratingthe Skolithos ichnofacies. Low diversity, moderate abundance, and the presence ofsimple dwelling structures suggest an opportunistic association. Based on cross-cuttingrelationships among biogenic structures and preservation of morphological details, anevolution from a soft to a relatively firm substrate is proposed. Two suites have beendistinguished in connection to progressive dewatering of floodplain sediments: 1)Palaeophycus tubularis Hall and small sub-horizontal and inclined trace fossils,developed in a soft substrate, and 2) Palaeophycus striatus Hall associated with smallsub-horizontal and inclined trace fossils, developed in a relatively firm substrate.