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

Abstract

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 the Valle del Cura Formation. The present study, based on extensive field work, robust geochronological and geochemical datasets, 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 retro-arc position of the main arc volcanism of the Doña Ana Group. The field evidence combined with radiometric and geochemical data demonstrate the synextensional characteristic of the volcanic sequence of the 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 (29°–30°S).

Neogene landscape evolution in the Andes of north-central Chile between 28 and 32°S: interplay between tectonic and erosional processes

“…To the east, the basement core is intruded by, or in faulted contact with, a block composed mostly of Permo-Triassic magmatic and volcanic rocks unconformably overlain by Oligocene-Miocene folded volcano-sedimentary rocks (Fig. 3;Maksaev et al 1984;Nasi et al 1990;Martin et al 1999;Bissig et al 2001;Winocur et al 2014). These rocks are unconformably covered by Miocene subhorizontal volcanic rocks and intruded by a north-south-trending Oligocene magmatic belt (Fig.…”

“…These rocks are unconformably covered by Miocene subhorizontal volcanic rocks and intruded by a north-south-trending Oligocene magmatic belt (Fig. 3;Maksaev et al 1984;Nasi et al 1990;Martin et al 1999;Bissig et al 2001;Winocur et al 2014). The area of the Frontal Cordillera to the east of the basement core is referred to here as the eastern Frontal Cordillera (Fig.…”

Geodynamic processes in the Andes of Central Chile and Argentina: an introduction

“…Winocur et al (2014) shed light on the age and evolution of this belt where major mining districts are located, based on extensive fieldwork as well as geochronological and geochemical data. After many years of walking and studying the Andes, Godoy (2014) remarks on the along-strike lithological variations of the Neuquén Basin ( Fig.…”

Physiographic and tectonic settings of high-sulfidation epithermal gold–silver deposits of the Andes and their controls on mineralizing processes

“…Volcanism in the Oligocene and early Miocene was voluminous in the El Indio belt (Bissig et al, 2001;Martin et al, 1995;Winocur et al, 2014) initially generating the 27-23 Ma Tilito Formation dacitic-toandesitic pyroclastic and volcaniclastic rocks and small volumes of basalts in an extensional setting (Winocur et al, 2014). The Tilito Formation is unconformably overlain by the dominantly-andesitic Escabroso (21-17 Ma) and Cerro de las Tórtolas (16.6-14 Ma) Formations ( Fig.…”