A wedge model by simulating several thicknesses between Springhill Formation and Serie Tobífera was made in the Cañadón Piedras Field, in northern Tierra del Fuego, Austral Basin. The purpose of this work is to evaluate the seismic response in post and pre-stack domains, related to the changes in the thickness of the Formation. This is significantly important since it is intended to identify regions where the Springhill Fm. presents low or zero thickness (altos pelados), are propitious to develop reservoir conditions in volcanic intervals. They may also help to explain the charge with hydrocarbons through the sandy facies acting as carriers. So, it is key to develop tools to map wedging of Springhill Fm. to identify associated zones with good reservoir conditions in the Tobífera Series. The results of the study through the interpretation of the values of P-Impedance allowed to discriminate and map the limits of the Springhill Fm. and the Tobífera Series, as well as to outline internal geometries in both intervals. It was observed that high impedance values correspond to lithologies of greater hardness and low chances of presenting good reservoir properties, while low impedance values are associated with less solid lithologies and with possibilities of presenting some type of porosity.