The geodynamic history of the Famatinian arc, Argentina: A record of exposed geology over the type section (latitudes 27°- 33° south)

From Crustal Thickening to Orogen‐Parallel Escape: The 120‐Myr‐Long HT‐LP Evolution Recorded by Titanite in the Paleozoic Famatinian Backarc, NW Argentina

“…The backarc was dominated initially by an extensional tectonic regime with the development of marine sedimentary basins between ~485 and 470 Ma (Astini, 2008; Bahlburg & Breitkreuz, 1991; Bahlburg & Hervé, 1997b; Büttner, 2009; Moya, 2015; Rapela et al, 2018). Deformation in the backarc switched to shortening after ~470 Ma (Weinberg et al, 2018), starting the event known as the Oclóyic phase (Cristofolini et al, 2014; Otamendi et al, 2020; Turner, 1975). This event was triggered by the arrival and docking of the Laurentian‐derived Precordillera/Cuyania block to the western margin of Gondwana and marked by regional unconformities formed during the inversion of the basins (Astini & Dávila, 2004; Bahlburg & Hervé, 1997a; Davila et al, 2003; Ramos, 2008; Thomas & Astini, 2003).…”

Upper-crustal architecture and record of Famatinian arc activity in the Sierra de Narváez and Sierra de Las Planchadas, NW Argentina

“…Previous work has resulted in a model of the first-order deformational, stratigraphic, petrologic characteristics of the Famatinian arc and timespans over which these processes operated (Rapela et al, 2018;Weinberg et al, 2018;Otamendi et al, 2020). These studies suggest a dominantly marine arc with both submarine and subaerial volcanic edifices built over a plutonic plumbing system restricted to the interval 463 ± 4 to 486 ± 7 Ma, with a peak of period of magmatic activity between 468 Ma and 472 Ma (Ducea et al, 2017;Rapela et al, 2018).…”

Architecture and kinematics of the Famatinian deformation in the Sierra Grande de San Luis: A record of a collisional history at 33° S latitude

“…In the geodynamic context of Argentina, the Famatinian arc is genetically related to an east-dipping subduction zone and to a backarc metamorphic belt bordering the preceding peri-Gondwanan Pampean orogen (Otamendi et J o u r n a l P r e -p r o o f al., 2020). Southward of 28° south latitude, the orogenic exhumation can be considered an episode associated with the closure of the arc due to a continent-to-arc collision (Astini and Dávila, 2004;Cristofolini et al, 2014;Otamendi et al, 2020).…”

“…Subduction-related magmatism in the Sierras Pampeanas segment ceased about ~465 Ma (Cristofolini et al, 2012;Ducea et al, 2015;Morosini et al, 2017;Otamendi et al, 2017). At this time, the Famatinian orogen began its intense construction, southward of 28° south latitude, so the arc and backarc were internally structured and differentially uplifted during the collision of the Laurentian-derived Cuyania/Precordillera microcontinent (Thomas and Astini, 1996;Benedetto, 2004;Otamendi et al, 2020) against the western margin of Gondwana (Astini and Davila, 2004;Ramos, 2004;Otamendi et al, 2009Otamendi et al, , 2017Ducea et al, 2010Ducea et al, , 2015Ramos et al, 2010;Cristofolini et al, 2014). This continent-arc collision conditioned the different orientations of the fault trends during the Mid Ordovician-Early Devonian times (von Gosen et al, 2002;Astini and Dávila, 2004).…”

“…12). An isostatic root rapidly developed synchronic with the Famatinian arc, and a voluminous and compositionally stratified igneous crust, immediately west of the Nogolí Metamorphic Complex, was developed before the orogenic stage between 488-465 Ma (Tibaldi et al, 2013;Ducea et al, 2015;Camilletti et al, 2020;Otamendi et al, 2020).…”