Field trip guide: Neogene evolution of the central Andean Puna plateau and southern Central Volcanic Zone

KAY, S.M., COIRA, B., AND MPODOZIS, C.

Field trip guides to the Backbone of the Americas in the southern and central Andes: Ridge collision, shallow subduction, and plateau uplift.

Geological Society of America Field Guide 13

Lugar: EEUU; Año: 2008; p. 119 - 183

This seven day field trip is designed to examine the distinctive magmatic, structural and sedimentological features of the late Oligocene to Recent evolution of the southern part of the high Central Andean plateau and the southern Central Volcanic Zone magmatic arc.  The stops for days 1 to 5 between 23° and 27°S latitude in Argentina emphasize the distinctive magmatic and structural features of the Puna region that comprises the southern half of the Andean plateau. Differences between the northern and southern Puna are highlighted. Among the various features to be observed are: (1) the giant Miocene ignimbrites of the northern Puna, (2) the distinctive normal and strike-slip faults and associated shoshonitic lavas of the central Puna and the intraplate and calc-alkaline lavas of the southern Puna, and (3) the silicic calderas of the southern Puna, and (4) the internal salar basins.  The stops on the last two days between 26.5° and 27.5°S latitude in Chile present a view of the Miocene to Recent frontal arc region on the western side of the plateau.  Particularly, the stops highlight the Miocene to Recent history of the late Miocene to Pliocene displacement of the magmatic front from the Maricunga belt on the western edge of the plateau to its present position in the southern Central Volcanic Zone.  Evidence for the timing of the uplift of the plateau, changes in the angle of the underlying subduction zone, delamination of the underlying continental crust and mantle lithosphere, and forearc subduction erosion are examined though out the course of the trip stops.