Cenozoic Orogenic Evolution of the Southern Central Andes (32–36°S)

Tectonic Regimes of the Central and Southern Andes: Responses to Variations in Plate Coupling During Subduction

“…The orogenic profile consists of an onshore forearc basin (Central Valley), magmatic arc (Principal Cordillera), hybrid basement‐involved and thin‐skinned contractional belt (Malargüe fold‐thrust belt), and an eastern foreland basin partitioned by a single basement uplift (San Rafael block) and overprinted by a large igneous province (Payenia volcanic field). A maximum crustal thickness of 45–50 km is the result of Andean shortening and possible earlier thickening (Farías et al, ; Giambiagi et al, , Giambiagi, Mescua, et al, ; Mescua et al, ; Tassara & Echaurren, ). Estimates of shortening range from 15 to 45 km and involve a complex combination of detached thin‐skinned fold‐thrust and basement‐involved structures that commonly reactivate Mesozoic normal faults (Fuentes et al, ; Giambiagi et al, ; Manceda & Figueroa, ).…”

“…This paper examines along‐strike (north‐south) and across‐strike (east‐west) variations in the Cretaceous‐Cenozoic geologic history of the central to southern Andes in an effort to emphasize potential temporal and spatial discrepancies in tectonic regimes for high‐shortening versus low‐shortening segments of the orogenic belt. Previous syntheses have focused on the magnitude and timing of deformation, episodic or cyclical changes in deformation and magmatism (including geochemical evolutionary trends), fluctuations in the geometry of the subducting slab, and the timing and mechanisms of surface uplift (e.g., Allmendinger et al, ; Barnes & Ehlers, ; Charrier et al, , ; DeCelles et al, ; Giambiagi, Mescua, et al, ; Garzione et al, ; Gianni et al, ; Haschke et al, , ; Kay et al, ; Kay & Coira, ; Oncken et al, ; Ramos et al, ; Ramos, , ; Ramos et al, ; Ramos & Kay, ; Rojas Vera et al, ; Trumbull et al, ). The goal here is not to replicate these valuable studies but to provide an integrated view of the Cretaceous‐Cenozoic records of (1) deformation (in terms of horizontal shortening, extension, or stasis), (2) magmatism (in terms of arc activity, arc cessation, or extension‐related within‐plate magmatism), and (3) sedimentary basin evolution (in terms of basin‐forming processes in foreland, hinterland, and forearc settings).…”

High-resolution compositional analysis of a fluvial-fan succession: The Miocene infill of the Cacheuta Basin (central Argentinian foreland)

“…Previous studies link the sedimentary infill of the Cacheuta Basin to the first stages of development of the main Andean range (Irigoyen, 1997;Irigoyen et al, 2000;Giambiagi and Ramos, 2003;Giambiagi et al, 2016). The onset of foreland sedimentation is coeval with a major phase of thrusting in the AFTB (Ramos et al, 1996a;Cegarra and Ramos, 1996;Irigoyen et al, 2000).…”

“…Uplift of the Frontal Cordillera was expressed diachronously farther north by the topographic ranges of the Cordon del Tigre (32°S) and successively by the Cordon del Plata at 33°S around 10 Ma (Giambiagi and Ramos, 2003). The topographic expression of the Frontal Cordillera is presently limited to the northern part of the normal subduction segment, disappearing toward the south at approximately 34°S (Giambiagi et al, 2016). The Frontal Cordillera was uplifted during the eastward advance of the deformation front by east-verging thrust faults (Porras et al, 2016) connected to a décollement level in Jurassic evaporites (Fock Kunstmann, 2005).…”

“…Initial uplift of the Precordillera took place with further eastward migration of the flat-slab system and has been constrained at ~10 Ma (Walcek and Hoke, 2012), coeval with the continued uplifting of the Frontal Cordillera. The latter prevented the propagation of the thrust belt towards the Cacheuta foreland basin (Giambiagi et al, 2016), whose exposed stratigraphic successions remain to date only gently folded and affected by minor faulting in the study area.…”