Lower to Middle Jurassic volcanism and Au–Ag mineralization at Cerro Moro District, Deseado Massif, Argentine Patagonia

Deformation along the Deseado Massif (Patagonia, Argentina) during the Jurassic Period and its relationship with the Gondwana breakup: paleomagnetic and geochronological constraints

“…The age of these units (~180 Ma; Fig. 1) is assumed to be close to the U--Pb ages of zircon presented by Matthews et al (2021) and Navarrete et al ( 2020) obtained from units that crop out 50 km to the east and 70 km to the northeast, respectively, with very similar lithological and structural features. The ChRM directions obtained from the samples of rhyolitic ignimbrites and breccias were defined between 270 and 330 • C and 630-680 • C (Fig.…”

“…3 Mean directions not considered because their respective VGP lies outside the 40 • cutoff angle (Wilson et al, 1972) 2019 and references therein) indicate clockwise rotations of the blocks that contain these units . However, the units belonging to the Chon Aike Formation east of the DM, of Early Jurassic age (Féraud et al, 1999;Matthews et al, 2021;Navarrete et al, 2020;Pankhurst et al, 2000;this work), indicate counterclockwise rotations (this work). Also, the paleopole presented by Vilas (1974), and considered "cratonic", in this work indicates a counterclockwise rotation.…”

“…Cenozoic units are omitted. Also, reliable Jurassic radiometric ages are presented: 1) this work, 2) Matthews et al (2021) deformation recorded in the units of the Jurassic Bahía Laura Complex. Also, this work aims to deduce the shape and paleogeography of this massif with respect to the rest of Patagonia, South America, and southwestern Gondwana during Jurassic times.…”

“…The poles of the Chon Aike Formation in the eastern zone of the DM indicate counterclockwise rotations of 27 • ± 7 • in the area near Laura Bay, 18 • ± 10 • in the Puerto Deseado area (Vilas, 1974), and 4 • ± 19 • that of the La Golondrina ranch area (although this last rotation is not representative since the uncertainty of the method is greater than the result). However, the lower degree of apparent rotation of the units of the La Golondrina ranch area could be ascribed to the fact that these units correspond to the fill of the vertical fissures of the volcanic eruptions, and not to deposits over the rotated blocks (Matthews et al, 2021;Navarrete, 2021;Navarrete et al, 2020Navarrete et al, , 2021. Furthermore, the pole of the Bajo Pobre Formation in the central area of the DM (see Figs.…”

Identifying crustal contributions in the Patagonian Chon Aike Silicic Large Igneous Province

“…The border between Argentina and Chile is highlighted by a blue line. Numbered references include the following: (1) Pankhurst et al ( 2000 ); (2) De la Cruz and Suarez ( 2006 ); (3) Poblete et al 2013 ; (4) Malowski et al 2016; (5) Foley et al 2022 ; (6) Matthews et al 2021 ; (7) Navarrete et al 2020 ; (8) Permuy-Vidal et al ( 2021 ); (9) Moreira et al ( 2009 ); (10) Dube et al ( 2003 ); (11) Hervé et al ( 2007 ) …”