Evolución del magmatismo de arco durante el Eoceno Medio - Mioceno Temprano en los Andes Patagónicos

LUCÍA FERNÁNDEZ PAZ; FLORENCIA BECHIS; VANESA LITVAK; ANDRÉS ECHAURREN; SOFÍA IANNELLI; ALFONSO ENCINAS; VERÓNICA OLIVEROS; ANDRÉS FOLGUERA; VÍCTOR VALENCIA

San Miguel de Tucumán

Congreso; XX Congreso Geológico Argentino; 2017

Asociación Geológica Argentina

El Maitén belt represents arc activity from middle Eocene to lower Miocene times, after a stage of arc waning and within plate magmatism. Its evolution was controlled by changes in subduction zone geometry as well as changes in convergence rates. Arc resumption by middle Eocene is characterized by a tholeiitic volcanism, which evolved to typically calc-alkaline series during Oligocene times. However, its final stages of basic lava flows took place in association with marine transgressions and alkaline intrusions. Geochemically, these lavas show arc signature with N-MORB sources, which contrasts with the alkaline sills that represent deeper sources.