MODELING AND HYDRODYNAMIC RECONSTRUCTION OF TIDAL INFLUENCED STROMATOLITES: YACORAITE FORMATION (MAASTRICHTIAN- DANIAN). JUJUY, ARGENTINA)

VILLAFAÑE, PATRICIO GUILLERMO; CÓNSOLE-GONELLA, CARLOS; CITTON, PAOLO; DÍAZ-MARTÍNEZ, IGNACIO; DE VALAIS, SILVINA

Congreso; 1st Palaeontological Virtual Congress; 2019

The architecture and external morphology in intertidal stromatolithic systems are influenced by the hydrodynamic energy of the environment. In the town of Maimará (Jujuy, Argentina), the Yacoraite Formation (Maastrichtian-Danian), exhibits a system of intertidal stromatoliths preserved in three-dimensional form. Although this type of system exists today, analogs in the fossil record are limited since tridimemsional exposure is not frequent. That is why the outcrops of the Yacoraite Formation in the town of Maimará, constitute a case study suggestive to analyze the relationship between these systems and the hydrodynamic energy of the environment.With this purpose, this site has been studied through in-situ survey, development of polished sections and thin sections. Finally, a three-dimensional model of system detail has been developed.As a result, it has been interpreted that the hydrodynamic energy of the medium has conditioned the stromatolithic growth in several scales. At macroscale, the morphology and architecture were influenced by the hydrodynamic action, interpreting the spaces between domes as first order discharge channels, which allow the passage of water.At mesoscale, the hydrodynamic energy of the environment interrupted the continuous growth of the microbial mat, giving rise to columnar structures. The space between the columns is interpreted as second and third order discharge channels according to their dimensions and position in the internal structure.In general, this model is consequent and a refinement of the inferred sedimentary environment for the unit in the Maimará section.