Geology, petrology and geochronology of sierra Valle Fértil - La Huerta batholith: Implications for the construction of a middle-crust magmatic-arc section

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

“…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). Furthermore, this collision produced the current exposures of the Famatinian deep paleo-arc that show a continuous deepening from north to south (Otamendi et al, 2010;Tibaldi et al, 2013;Cristofolini et al, 2014) and from east to west (Camilletti et al, 2020). During the Famatinian belt construction, the deformation was regionally resolved in different ways; through large scale fold and thrust belts in the upper crust (Astini and Dávila, 2004), along major shear zones in the front and margins of the Famatinian paleo-arc (von Gosen and Prozzi, , 2005Höckenreiner et al, 2003;Cristofolini et al, 2014;Mulcahy et al, 2014), through large-scale west-verging shear zones located in the Pampean basement (Sims et al, 1997;Martino, 2003;Cristofolini et al, 2017;Semenov et al, 2019), and double-vergent structures developed in the paleo-backarc (Larrovere et al, 2017;Christiansen et al, 2019).…”

“…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).…”

Mixing dry and wet magmas in the lower crust of a continental arc: new petrological insights from the Bear Valley Intrusive Suite, southern Sierra Nevada, California

“…Detailed studies of other arc crustal sections demonstrate that ultramafic-mafic cumulates and derivative felsic intrusions can be produced dominantly by fractional crystallization of a single basaltic parental melt with or without crustal contamination (e.g., Jijal and Chilas complexes in the Kohistan arc, Jagoutz 2010; Jagoutz et al, 2011; Chugach mountains in the Talkeetna arc, Greene et al, 2006;Sierra Valle Fértil -La Huerta in the Famatina arc, Walker et al, 2015;Camilletti et al, 2020; Chelan Complex in the Cascades, Dessimoz et al, 2012; the Dariv Igneous Complex in Western Mongolia, Bucholz et al, 2014b). While these examples demonstrate that mixing of dry and wet mafic magmas is not a prerequisite to produce intermediate to felsic arc crust, we believe that the mixing and differentiation of multiple distinct primary melts is likely a common process in arc lower crust.…”