La Peligrosa caldera (47° 15′S, 71° 40′W): A key event during the Jurassic ignimbrite flare-up in Southern Patagonia, Argentina

La Josefina Au–Ag deposit (Patagonia, Argentina): A Jurassic epithermal deposit formed in a hot spring environment

“…During the Middle to Upper Jurassic (188-152 Ma) a widespread volcanism occurred in Patagonia and Antarctic Peninsula giving rise to the Chon Aike Large Igneous Province (Pankhurst et al, 1998(Pankhurst et al, , 2000Sruoga et al 2008), developed under an extensional tectonic setting related to the early break-up of the Gondwana supercontinent. The Deseado Massif is a geological province of about 60,000 km 2 located in the southern portion of the Argentinean Patagonia and hosts numerous epithermal Au-Ag deposits related to Jurassic volcanics (Schalamuk et al, 1997;Schalamuk et al, 1999a, Fig.…”

Late Cenozoic brittle deformation in the Southern Patagonian Andes: Record of plate coupling/decoupling during variable subduction?

“…The studied sector is subdivided by the Basement thrust, a segmented fault with east vergence and ~N–S orientation (Figures a and 3a), which superposes Jurassic–Cretaceous and Late Cenozoic rocks over the Miocene units (Giacosa & Franchi, ). The basement front segment delimited by the Sierra Colorada Fault is shifted towards the east relative to the regional trend (Figures a,b and a), a characteristic that can be related to the tectonic inversion of Mesozoic rift structures in the foreland (Giacosa & Franchi, ; Sruoga, Japas, Salani, & Kleiman, ), as shown also in the southern end of the SPA (Ghiglione et al., ; Likerman, Burlando, Cristallini, & Ghiglione, ). The structural domain located to the west of the Basement thrust is characterized by NNW‐oriented fold‐and‐thrust sheets involving Palaeozoic basement with ductile deformation, Jurassic synrift volcanics and Cretaceous retroarc sequences (Ghiglione, Ramos, Cuitiño, & Barberón, ; Ghiglione et al., ; Giacosa & Franchi, ).…”

“…We suggest that overall Neogene deformation may have been dominated by transpressional right‐lateral deformation partitioning along the Basement thrust (Figure c,d), that is a now extinct ancestor of the Liquiñe‐Ofqui fault. For the particular case of the Sierra Colorada fault segment, an origin during Jurassic extensional/trantensional deformation has been proposed (Sruoga et al., ), that is providing a weakness zone readily reactivated during oblique subduction and related partition of deformation. Subordinate and scattered extensional deformation is affecting the Basement domain (Figure ), interpreted as relicts from the Jurassic rift.…”

Basement-involved deformation overprinting thin-skinned deformation in the Pampean flat-slab segment of the southern Central Andes, Argentina

“…This concordance of magmatism and uplift ages would support melt-enhanced deformation (‘tectonic surges’ triggered by melt-lubricated shear zones; Hollister & Crawford, 1986) rather than heating-enhanced deformation (Coney, 1972; Burchfiel & Davis, 1975; Ramos, Cristallini & Perez, 2002). The active role of magmatism in increasing rock ductility is also supported by brittle–ductile shear zone substituting fault development (see also Kleiman & Japas, 2009; Japas, Urbina & Sruoga, 2010; Oriolo et al 2014; Sruoga et al 2014).…”