Structural controls on Jurassic gold mineralization, and Cretaceous-Tertiary exhumation in the foreland of the southern Patagonian Andes: New constraints from La Paloma area, Deseado Massif, Argentina

Tectono-thermal history of the intraplate San Bernardo fold and thrust belt in central Patagonia inferred by low-temperature thermochronology

“…Nevertheless, few AHe ages from local areas of the northern Patagonian Broken Foreland record younger Neogene ages and have been related to the close and coeval intraplate volcanic activity (Savignano et al, 2016;Genge et al, 2021), as we suppose it is the case along the San Bernardo FTB. We thus conclude that, as previously proposed for other parts of the Patagonian Broken Foreland (Savignano et al, 2016;Fernández et al, 2020;Genge et al, 2021), the main deformation of the southern San Bernardo FTB occurred from the Cretaceous to the early Paleogene, while the middle-late Miocene deformation was modest (Figure 6C), especially in terms of vertical displacements.…”

“…Gianni et al, 2017), which, according to Maloney et al (2013), could be related to the change of convergence of the Nazca plate. This deformation event was also evidenced in the northern (Gastre Basin;Bilmes et al, 2013) and the southern Patagonian Broken Foreland (Deseado Massif; Giacosa et al, 2010), although lowtemperature in-situ thermochronology studies in these areas suggest minor vertical displacements during the Neogene as they evidence a lack of thermochronology signal since the Paleogene (Savignano et al, 2016;Fernández et al, 2020;Genge et al, 2021). Indeed, the latter thermochronology data and associated thermal modeling characterize a slow cooling of the whole foreland since the Late Cretaceous, with the lack of any particular thermal event.…”

“…Thus, according to these authors, the San Bernardo FTB may have experienced a constant and moderate tilting to the north since the middle-late Miocene. Nevertheless, taking into account the AFT data, which are not able to detect minor vertical movements, and thermal modeling obtained south of the study area into the Deseado Massif (Fernández et al, 2020), the dynamic topography in the central Patagonian foreland may have minor effects on the low-temperature thermochronometers as no particular accelerated cooling events have been evidenced during the Miocene. Furthermore, the preservation of fluvial terraces around the San Bernardo FTB demonstrates that low erosion affected the study region, possibly related to climatic changes since the late Miocene (Guillaume et al, 2009).…”

Influence of structures and lithologies in the morphology and localization of Au–Ag mineralization at Martinetas deposit, Don Nicolas mine, Deseado Massif, Argentina

“…Multi-scale structural analysis of Au-Ag mineralization in veins shows that the distribution of the districts is regionally controlled by normal to oblique slip fault system, in response to the NE-SW extensional direction (Jovic et al, 2014;Fernández et al, 2019). However, each district shows local controls dependent on its own geological, lithological and structural characteristics (Jovic et al, 2014).…”

Early Cretaceous to Cenozoic Growth of the Patagonian Andes as Revealed by Low‐Temperature Thermochronology

“…Initial Aptian‐Cenomanian contractional deformation in the SPA was suggested by forced regressions in the foreland basin (Ghiglione et al., 2015) and angular unconformities separating Cretaceous from younger rocks (Aramendía et al., 2018; Ronda et al., 2019). However, the regional distribution of Cretaceous low‐temperature thermochronometric ages is insufficient to backup a direct relation between cooling and shortening (Fernández et al., 2020; Fosdick et al., 2013). Within the studied area (Figure 1) existing Cretaceous zircon (U‐Th)/He and zircon fission tracks data have been linked to cooling following crystallization (Andrić‐Tomašević et al., 2021; Thomson et al., 2001).…”