Geometrías de crecimiento en sedimentos paleógenos en el borde Puna-Cordillera Oriental en la provincia de Jujuy

LÓPEZ STEINMETZ, ROMINA; HONGN, FERNANDO; MONTERO LÓPEZ, CAROLINA

San Miguel de Tucumán

Congreso; XX Congreso Geológico Argentino; 2017

Growth strata and structures are developed in tectonic settings when sedimentation and deformation are coevals (Riba 1973); depending on the ratio between sedimentation/uplift rates, different geometries will be generated (see Poblet 2012). When the sedimentation rate is higher than uplift rate, a growth wedge is developed defined by variations in the bed dips and thicknesses (e.g. Poblet 2012), so if these strata are not eroded, they constitute an excellent indicator to constraint the deformation time. There are several examples of growth geometries along the Puna and Cordillera Oriental of Northwest Argentina which are key evidences of the Paleogene deformation event of the Andean orogeny (Hongn et al. 2007, Payrola et al. 2009, del Papa et al. 2013, Aramayo et al. 2015, Montero-López et al. 2016). In this contribution we present new data from an area (Los Colorados-Tucsa) located in the transition of Puna and Cordillera Oriental (Jujuy province) showing evidences of growth geometries developed in the sediments of the Eocene Casa Grande Formation. They are unconformable overlying the Cretaceous-Paleogene sediments of the rift Salta Group.