This book provides an overview of newly gathered material focusing on the opening and closure of The Neuqun Basin. The Neuqun Basin contains the most important hydrocarbon reservoirs in Argentina and therefore is characterized by a profound knowledge of the sedimentation mechanisms and closure times. During the last 10 years a considerable amount of new information has been produced that illustrates a complex evolution that involves more than one synrift stage during its evolution, an aborted sag phase associated with the inception of a first foreland basin in late Early Cretaceous times, two extensional destabilizations in the Late Cretaceous-Paleocene and late Oligocene times and a Neogene magmatic expansion coetaneous to a last mountain building. These processes have produced a polyphasic complex structure that exhumed the rich sedimentary record that characterizes the basin.