Paleogene Arc-Related Volcanism in the Southern Central Andes and North Patagonia (39°?41° S)

IANNELLI, SOFIA B.; FERNÁNDEZ PAZ, LUCÍA; LITVAK, VANESA; JONES, E ROSEMERY; RAMOS MIGUEL ESTEBAN; FOLGUERA, ANDRÉS; RAMOS, VICTOR A.

The Evolution of the Chilean-Argentinean Andes

Springer

Año: 2018; p. 343 - 359

The influence of tectonic processes in evolution of magmatic suites evaluated through their geochemical signature has always been a subject of debate. Late Paleocene arc volcanism in the Southern Central Andes, particularly in North Patagonia, can be used to infer a direct relationship between magmatic episodes and tectonic changes along the Andean margin. Eocene arc-related volcanism (~44 Ma) in the North Patagonian Andes shows evidence for limited influence of the subducting slab on the composition of arc magmas and they exhibit an alkaline tendency. By Oligocene times (~29 Ma), arc volcanic sequences in the Auca Pan depocenter show predominantly arc-like geochemical signatures and have been derived from a calc-alkaline source. However, a comparison with younger arc sequences (