Field trip guide; Andean Cordillera and backarc of the south-central Andes ( approximately 38.5 degrees S to 37 degrees S)
Field trip guide; Andean Cordillera and backarc of the south-central Andes ( approximately 38.5 degrees S to 37 degrees S) (in Field trip guides to the backbone of the Americas in the Southern and Central Andes; ridge collision, shallow subduction, and plateau uplift, Suzanne Mahlburg Kay (editor) and Victor A. Ramos (editor))
Field Guide (Geological Society of America) (2008) 13: 23-55
The Andes of the Neuquen Mesozoic basin have experienced multiple episodic tectonic events as a consequence of the changes of the plate tectonic boundary configuration. Each episode of deformation has overprinted the previous one, making it difficult to unravel the Andean tectonic history. The first deformation event took place in the uppermost Cretaceous with the formation of the Agrio fold-and-thrust belt. This event was related to the shallowing of the subducting plate recorded by the migration of the volcanic arc toward the foreland. During the late Oligocene-early Miocene, an extensional event, related to the steepening of the subducted plate, affected only the hinterland region causing the opening of the Cura Mallin basin. This basin was closed during the late Miocene, together with the development of a new fold-and-thrust belt that reactivated the previous structures. During the Late Tertiary, two more episodes of extension and compression affected the Andean area. The trip focuses on the field evidence that documents this complex history of evolution by looking at evidence of the sequence of the distinct tectonic events.