Magmatic and tectonic evolution of the Oligocene Valle del Cura basin, Main Andes of Argentina and Chile: Evidence for generalized extension

WINOCUR, DIEGO; LITVAK, VANESA D.; RAMOS, VICTOR A.

GEOLOGICAL SOCIETY OF LONDON SPECIAL PUBLICATION

The Geological Society

Lugar: Londres; Año: 2015 vol. 399 p. 109 - 130

0305-8719

The magmatic history and tectonic evolution of the Valle del Cura region has received the attention of several studies in recent years, particularly as part of a larger area of interest named the Indio Belt. These studies have suggested an Eocene volcanic sequence known as Valle del Cura Formation. The present study based on an extensive field work, robust geochronological and geochemical data sets, shows an Oligocene to early Miocene age for this unit, similar to the Doña Ana Group. The tectonic setting that controlled the volcanism of the Valle del Cura Formation was extensional and corresponds to a retroarc position of the main arc volcanism of Doña Ana Group. The field evidences added to the radiometric and geochemical data demonstrate the synextensional characteristic of the volcanic sequence of Valle del Cura Formation and the Doña Ana Group at these latitudes. This characteristic was dominant at the central part of the Pampean Flat Slab (29º-30ºS).