The evolution of the Austral Basin includes an early rifting stage (Jurassic- Early Cretaceous) related with Gondwanan break out, filled whith volcanic and volcaniclastic rocks, known as “Bahia Laura Group” in the Deseado Massif; “El Quemado Complex in the Patagonian Andes and “Lemaire Fm.” in Tierra del Fuego Province; all of these stratigraphic units are englobed in the subsurface denomination “Serie Tobífera” (Cortinas et al., 2005).This “Serie Tobífera” was historically considered the economic basement of the basin; however, in the 70s ́and the 90s śomes hydrocarbon accumulations were found in the Santa Cruz province (Ea. Dos Lagunas, Punta Loyola) Argentina, and in Magallanes province (Gaviota, Gaviota Norte, Flamenco) Chile. The discoveries continue in Chile, in the 2010 by Geopark. In the 2015, YPF resume the exploration of this play drilling four wells in the San Sebastian Block (Chile), with initial flow rates from 30 to 153 m3/d of oil and 160K m3/d of gas. Exploration discoveries continues in Argentina, in Lago Fuego Block, with production rates between 40K and 80K m3/d of gas.This paper describes the main characteristics of this play including the follows items: 1) Strong compositional heterogeneity defined by Rx fluorescence, plus an interpretation of thin section of cuttings, latter applied to individualize volcanic events. 2) Fractured structural Highs, identified with 3D seismic and attributes. 3) Fractured reservoirs characterized by borehole images, side well cores and well tests