TIDAL SEDMENTATION UNDER HIGH-ENERGY INFLUENCE: PHYSICAL AND BIOLOGICAL INTERACTIONS

PAN, J; CUADRADO, D.G.; GOMEZ, E.A.; RANIOLO, A.; MAISANO, L.

PUERTO MADRYN

Conferencia; 9th International Conference on Tidal Sedimentolog; 2015

The recognition of signatures in the rock record and the interpretation of associated sedimentary processes is one of the major challenges facing tidal sedimentologists. Detailed observations and quantitative estimates of parameters in modern environments, including time series data, facilitate the comprehension and understanding of the processes lying behind tidalites. In addition, the preservation potential of sedimentary structures plays an important role in the interpretation of the sedimentary rock record The present investigation deals with tidal processes on a supratidal pan, the inundation of which is primarily controlled by the local wave climate and atmospheric conditions (prevailing direction, duration and intensity of winds) acting in conjunction with specific geomorphological characteristics of the environment. Of paramount importance is the fact that the supratidal pan under consideration is colonized by microorganisms forming thick microbial mats which generate a smooth and elastic surface, thereby preserving particular sedimentary structures currently experiencing early diagenesis. Based on the interplay between moisture variation and event-controlled high tidal-current shear stress, deformed microbial structures have recently been documented and described at Paso Seco, Argentina (S40º39?- W62º14?; Cuadrado et al., 2015). The zone constitutes a remnant tidal channel/tidal flat which is today choked by a sand spit formed by NE longshore sediment transport. Through successive campaigns, the effects of seawater inundation of the study area during highenergy events were recorded.