It is located in the Sierras de Cordoba mountain chain.[4] It formed during the late Miocene, when a progressive shallowing of the subductingNazca Plate caused volcanic activity to retreat 500 kilometres (310 mi) from the main Andes into the land behind the mountain chain.[2] This did result in a typical shallow slab chemistry of the Pocho rocks.[4] Volcanic activity at Pocho is dated about 4.7 +- 0.3 million years ago[5] and took place over two cycles.[6] Seismic activity in the area may indicate the presence of a residual magma chamber however,[7] which would also explain anomalous crustal seismic velocities in the area.[8]
References
^Coira, B.; Kay, S. Mahlburg; Viramonte, J. (1993-08-01). "Upper Cenozoic Magmatic Evolution of the Argentine Puna—a Model for Changing Subduction Geometry". International Geology Review. 35 (8): 697. doi:10.1080/00206819309465552. ISSN0020-6814.