Within the South Atlantic waters adyacent to the Malvinas islands and the Argentine mainland there are three sedimentary basins with potential major hydrocarbon resources; the Magallanes, Malvinas, and Malvinas rise. The Magallanes basin an offshore extension of the producing areas in Chile and Tierra del Fuego lies entirely in water less than 300 feet. The assesment of undiscovered hydrocarbon for this offshore portion is at least equivalent to that already found onshore. East of the Rio Chico or Dungeness arch between the Malvinas iSlands and the mainland lies the Malvinas basin. YPF the Argentine state oil company has run more than 16.000 km of seismic reflection lines which have provided a fairly detailed knowledge of the structural configuration and basin evolution. Three distinct tectonic environments are present, a platform area with a sedimentary section up to 4.000 m thick, a transitional hinge zone and a deep trough parallel to the Andean belt.The hydrocarbon potential of the sedimentary sequence composed of marine Tertiary and Cretaceous is now being tested by the Ciclon wildcat the first offshore well drilled in these waters.