The Time-Space Distribution of Cenozoic Volcanism in the South-Central Andes: a New Data Compilation and Some Tectonic Implications

Cenozoic tectonostratigraphic evolution and architecture of the Central Andes in northern Chile based on the Aquine region, Western Cordillera (19°-19º30’ S).

“…A Oligocene volcanic lull lasted until the late Oligocene-early Miocene (Trumbull et al, 2006), when regional-scale explosive volcanism gave origin to the Utayane and Oxaya Formations (Figs. 9b and 11b) concomitant to a strong peak in plate convergence rates at ca.…”

Migrating deformation in the Central Andes from enhanced orographic rainfall

“…Slip along these faults has been reactivated through changes in the stress regime 55,56 , and particularly in response to a change from dominantly vertical thickening to orogen-parallel stretching 55 . Th e infl uence of these faults is strong particularly for the post 7.9 Ma volcanic activities on the plateau, as inferred from age-density analyses of volcanoclastic rocks 54 . As these faults accommodate orogen-parallel variations in shortening 55 and are not related to subduction geometries 55 , we suggest that the reactivation of these faults may also be related to orographic-rainfall induced changes in erosion rates that caused the transfer of shortening from the western margin to the Eastern Escarpment in the Central Andes.…”

“…1a ). Th ese structures dissect the entire crust of the Puna Plateau between 21 ° S and 28 ° S and are associated with the ascent of magma 54,55 . Slip along these faults has been reactivated through changes in the stress regime 55,56 , and particularly in response to a change from dominantly vertical thickening to orogen-parallel stretching 55 .…”

The Pampa del Tamarugal Forearc Basin in Northern Chile: The Interaction of Tectonics and Climate

“…From 26-5 Ma convergence was <10 from normal and at a high rate (120 km/my), followed during the Pliocene and Quaternary by 5 increase in obliquity as well as a slower rate (80 km/my) (Somoza and Ghidella, 2005). The Central Andes were at the end of a l0-millionyear lull in volcanic activity at 27 Ma (James and Sacks, 1999;Trumbull et al, 2006;Kay and Coira, 2009), with elevations about one-quarter of their current magnitude (Charrier et al, 1994;Gregory-Wodzicki, 2000;Ghosh et al, 2006;Garzione et al, 2006Garzione et al, , 2008, and >600 km wide (Elger et al, 2005;Barnes and Ehlers, 2009). By about that time, sedimentation was established throughout the basin (Victor et al, 2004;Charrier et al, 2007;Jordan et al, 2010).…”

“…Over the span of the Cenozoic, the volcanic arc migrated substantially in position (see James and Sacks, 1999;Kay et al, 1999;W€ orner et al, 2000;Trumbull et al, 2006;Charrier et al, 2007). From 65 to 35 Ma, the volcanic arc lay within the modern forearc basin, followed by 10 million years with no volcanic activity (Trumbull et al, 2006). Between 25 and 15 Ma, the western margin of the volcanic arc was established at the eastern margin of what is now the northern PdT basin, and then shifted 20 km eastward during the Late Miocene through Quaternary.…”