La vida en un lago carbonático del Cretácico Superior: análisis icnológico y paleobiológico de la Formacion Yacoraite en la subcuenca de Tres Cruces, Jujuy.

KRAPOVICKAS, VERONICA; MARSICANO, CLAUDIA; BARREDO, SILVIA

Congreso; XX Congreso Geológico Argentino; 2017

Abstract. The life in a Late Cretaceous carbonate lake: ichnological and paleobiological analysisof the Yacoraite Formation in the Tres Cruces sub-basin (Tres Cruces, Jujuy).Various authors have argued about the putative marine vs continental origin of the YacoraiteFormation (Salta Group) based mainly on its body fossil content and sedimentology. This workis focused on the ichnologic content of the Yacoraite Formation at the Tres Cruces sub-basin andreinforced by other paleontologic and sedimentologic evidences. The research reveals fiveichnofabrics included in three ichnofacies models. The Lockeia ichnofabric record traces ofepibentonic and infaunal subaqueous animals in shallow carbonatic environments, associated todomic microbialites, gastropods, ostracods, and scarce miliolid forams. The Treptichnus-SGPichnofabric suggest an epibentonic and shallow endobentonic fauna developed in an oxygenatedfresh water lake. It is associated to smooth shelled heterodont bivalves and plant debris. Bothichnofabrics are included within the Mermia Ichnofacies. The Palaeophycus-Taenidiumichnofabric and the Scoyenia ichnofabric corresponds to the pre-desiccation and post-desiccationsuits, respectively, of the Scoyenia Ichnofacies thus denoting the fluctuation (exposition vs.inundation) of the water in the shore margin. These ichnofabrics are associated to charophytes