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

Abstract

A complex interaction of endogenous and exogenous processes took place in the Southern Patagonian Andes (SPA) at the latitude of the Chile triple junction (CTJ) (Figure 1), resulting from Cretaceous-Miocene tectonic crustal shortening and thickening in a geodynamic setting involving the subduction of oceanic ridges and late Miocene-Quaternary glaciations (e.g.,

Geodynamic and Climatic Forcing on Late‐Cenozoic Exhumation of the Southern Patagonian Andes (Fitz Roy and Torres del Paine massifs)

“…geomorphologic (Mercer and Sutter, 1982;Lagabrielle et al, 2004Lagabrielle et al, , 2007Lagabrielle et al, , 2009Lagabrielle et al, , 2010Rabassa, 2008;Rabassa et al, 2005Rabassa et al, , 2011, and thermochronological evidence (Andrić-Tomašević et al, 2021;Christeleit et al, 2017;Fosdick et al, 2013;Georgieva et al, 2016Georgieva et al, , 2019Glodny et al, 2008;Ronda et al, 2022;Thomson et al, 2001Thomson et al, , 2010Thomson et al, , 2010Thomson et al, , 2010Willett et al, 2020). The Andean topography quickly responded to the transition from fluvialdominated to glacial-dominated erosional processes (Figures 10b-10f), as proposed for other alpine environments (Champagnac et al, 2014;Egholm et al, 2009;Herman et al, 2013;Shuster et al, 2005Shuster et al, , 2011Valla et al, 2011).…”

“…We present new apatite and zircon (U-Th)/He (AHe and ZHe) thermochronological data sets from two of the most emblematic massifs of the Southern Patagonia Andes: the Fitz Roy (FzR, 49°S) and Torres del Paine (TdP, 51°S) (Figures 1-4). These massifs were emplaced around 16.7 ± 0.3 Ma (Ramírez de Arellano et al, 2012) and 12.5 ± 0.1 Ma (Leuthold et al, 2012), respectively, in the regions swept by the CTJ passage during the Late Miocene, and thus may have recorded the earlier effects of ridge collision and subduction, besides those of late Cenozoic glaciation (Andrić-Tomašević et al, 2021;Ávila et al, 2023;Christeleit et al, 2017;Fosdick et al, 2013;Georgieva et al, 2016Georgieva et al, , 2019Guillaume et al, 2009Guillaume et al, , 2013Ramos, 2005;Ronda et al, 2022;Stevens Goddard & Fosdick, 2019;Thomson et al, 2001;Willett et al, 2020). Additionally, we present new apatite 4 He/ 3 He thermal modeling for the TdP massif, which resolves the latest stage of rock cooling and provides additional insights into the Pliocene-Pleistocene rock exhumation history of the area.…”

“…In the Southern Patagonian Andes, glacial landscapes and related sedimentary deposits have been proposed to reflect the onset of major glaciations during late Miocene at ca. 7 Ma (Christeleit et al, 2017;Georgieva et al, 2016Georgieva et al, , 2019Lagabrielle et al, 2010;Mercer & Sutter, 1982;Rabassa, 2008;Ronda et al, 2022;Thomson et al, 2001Thomson et al, , 2010Willett et al, 2020). Currently, the Northern Patagonian (NPI, 46-47°S), the Southern Patagonian (SPI, 48-52°S) and the Cordillera Darwin (54°S) icefields are located along the strike of the internal domain of the orogen (Figure 1).…”

Thermochronological Evidence for Eocene Deformation in the Southern Patagonian Andes: Linking Orogenesis Along the Patagonian Orocline

“…In either case, plate reorganization associated with the early opening of the Drake Passage at 50 Ma can be linked to retroarc compressional deformation in the southern Patagonian Andes. North of our study area, ∼48–44°S, AHe, AFT, ZHe, and ZFT data sets and thermal history models incorporating AFT and ZHe data sets do not show evidence of Eocene–Oligocene exhumation and inferred deformation (Georgieva et al., 2016; Guillaume et al., 2013; Ronda et al., 2022; Thomson et al., 2001, 2010). It is possible that thermal history modeling incorporating data from a higher temperature thermochronometric system is required to identify this signal.…”

Mechanisms of Subsidence and Uplift of Southern Patagonia and Offshore Basins During Slab Window Formation

“…Thermochronological data revealed the advance of the exhumation of SPA from the western basement domain toward the eastern FTB (Ghiglione et al., 2016; Thomson et al., 2001). The thrusting of the eastern FTB accommodated the crustal thickening and widening of the orogenic wedge (Fosdick et al., 2011), resulting in a main phase of tectonic uplift between ∼22 and 18 Ma (Fosdick et al., 2013; Ronda et al., 2022). The late Oligocene to early Miocene tectonic deformation of SPA was accompanied by the extensive marine transgression, which first affected the present Atlantic coastline around 25 Ma (San Julian Formation).…”