Constraints on the Neogene growth of the central Patagonian Andes at the latitude of the Chile triple junction (45–47°S) using U/Pb geochronology in synorogenic strata

Folguera, Andrés; Encinas, Alfonso; Echaurren, Andrés; Gianni, Guido M.; Orts, Darío; Valencia, Víctor A.; Carrasco, Gabriel

doi:10.1016/j.tecto.2018.06.011

Cited by 41 publications

(32 citation statements)

References 78 publications

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“…Two orogenic stages, a late Early Cretaceous to early Paleogene stage and a middle Miocene to Pliocene stage, have been recognized in the Patagonian Cordillera, the Patagonian Precordillera ( Fig. 1A; also named the Precordilleran system, or the Eastern Precordillera, or the North Patagonian fold and thrust belt; e.g., Bilmes et al, 2013;Folguera et al, 2018;Orts et al, 2015;Ramos et al, 2014), and the socalled broken foreland generated by the uplift of basement blocks related to the contractional reactivation of older crustal discontinuities and the deformation of former graben/half graben systems (Echaurren et al, 2016;López et al, 2019). These latter were formed in the context of Early Jurassic to Early Cretaceous extension associated with a protracted slab rollback, which is coherent with the westward shift of arc magmatism (Ramos, 1999(Ramos, , 2010.…”

Section: Introductionmentioning

confidence: 99%

The role of slab geometry in the exhumation of cordilleran-type orogens and their forelands: Insights from northern Patagonia

et al. 2021

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In cordilleran-type orogens, subduction geometry exerts a fundamental control on the tectonic behavior of the overriding plate. An integrated low-temperature, large thermochronological data set is used in this study to investigate the burial and exhumation history of the overriding plate in northern Patagonia (40°−45°S). Thermal inverse modeling allowed us to establish that a ∼2.5−4-km-thick section originally overlaid the Jurassic−Lower Cretaceous successions deposited in half-graben systems that are presently exposed in the foreland. Removal of the sedimentary cover started in the late Early Cretaceous. This was coeval with an increase of the convergence rate and a switch to a westward absolute motion of the South American Plate that was accompanied by shallowing of the subducting slab. Unroofing was probably further enhanced by Late Cretaceous to early Paleogene opening of a slab window beneath the overriding plate. Following a tectonically quiescent period, renewed exhumation occurred in the orogen during relatively fast Neogene plate convergence. However, even the highly sensitive apatite (U-Th)/He thermochronometer does not record any coeval cooling in the foreland. The comparison between Late Cretaceous and Neogene exhumation patterns provides clear evidence of the fundamental role played by inter-plate coupling associated with shallow slab configurations in controlling plate-scale deformation. Our results, besides highlighting for the first time how the whole northern Patagonia foreland was affected by an exhumation of several kilometers since the Late Cretaceous, provide unrivalled evidence of the link between deep geodynamic processes affecting the slab and the modes and timing of unroofing of different sectors of the overriding plate.

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Section: Introductionmentioning

confidence: 99%

The role of slab geometry in the exhumation of cordilleran-type orogens and their forelands: Insights from northern Patagonia

et al. 2021

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“…The Andean history of the North Patagonian region involved the development of a foldthrust belt (Giacosa and Heredia, 2004;Giacosa et al, 2005;García Morabito and Ramos, 2012), structural partitioning of the adjacent foreland basin (Bilmes et al, 2013;Gianni et al, 2015;Echaurren et al, 2016;Savignano et al, 2016;Franzese et al, 2018), and evolution of the magmatic arc linked to variations in slab dip (Pankhurst et al, 1999;Suárez and de la Cruz, 2001; Folguera and Ramos, 2011;Echaurren et al, 2016Echaurren et al, , 2017Gianni et al, 2018;Folguera et al, 2018aFolguera et al, , 2018bFernández Paz et al, 2018). However, most of the prevailing tectonic models have been proposed on the basis of structural and magmatic records, with limited information regarding sedimentary basin dynamics (i.e., timing of deposition, duration of stratigraphic hiatuses, and potential shifts in sedimentary provenance).…”

Section: Introductionmentioning

confidence: 99%

Cretaceous-Cenozoic growth of the Patagonian broken foreland basin, Argentina: Chronostratigraphic framework and provenance variations during transitions in Andean subduction dynamics

Butler

Horton

Echaurren

et al. 2020

Journal of South American Earth Sciences

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The Cretaceous-Cenozoic evolution of the Patagonian broken foreland basin system at 42-43°S in the northern Chubut province of Argentina is associated with variable retroarc phases of fold-thrust belt shortening, extension, and basement uplift during changes in the dynamics of oceanic slab subduction. Basement inheritance and progressive shallowing of an east-dipping subducting slab are important mechanisms of foreland partitioning, as dictated by the preexisting (pre-Andean) structural architecture and forelandward (eastward) advance of Late Cretaceous arc magmatism. Previously recognized growth strata help define the timing of fold-thrust belt shortening and retroarc basement-involved uplift, but the precise consequences for sediment routing remain poorly understood, with uncertainties in patterns of basin evolution before, during, and after shallowing and resteepening of the subducting slab. In this study, distinctive sediment source regions and magmatic histories enable evaluation of the stratigraphic and tectonic evolution of the retroarc foreland basin using new provenance results, maximum depositional ages, and isotopic signatures from detrital zircon U-Pb geochronology and Lu-Hf geochemical analyses. A compilation of published bedrock crystallization ages and distributions of metamorphic and igneous basement rocks identify: a western source region defined by the Andean magmatic arc and associated pre-Andean basement; and an eastern source region consisting of intraplate magmatic units and the North Patagonian Massif. We demonstrate that Aptian-Cenomanian retroarc basin fill was derived principally from the basement massif and intraplate volcanic units to the east, followed by a Late Cretaceous

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“…The Cenozoic growth of the North Patagonian Andes between 45° S and 47° S has been recently addressed by Folguera et al (2018a). During this Era, they identified a discrete pulse of contraction at ca.…”

Section: Age Constraints On the Metamorphism Of The Traiguén Formatiomentioning

confidence: 99%

Mid-Cenozoic SHRIMP U-Pb detrital zircon ages from metasedimentary rocks in the North Patagonian Andes of Aysén, Chile

Quezada

Hervé

Calderón

et al. 2021

andgeo

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Previously undated low-grade metamorphic rocks from the Puerto Cisnes-Queulat area (44°30’ S) contain detrital zircons of mid-Oligocene age (ca. 28 Ma). Their outcrops represent the easternmost occurrence of the late Oligocene to early Miocene marine volcano-sedimentary Traiguén Formation; previous correlation with the Paleozoic metamorphic basement of this sector of the North Patagonian Andes is thus refuted. A similar age and provenance were obtained for a paraconglomerate bed of the La Junta Formation ca. 80 km to the north, which is thought to represent a high-energy lateral facies variation of the Traiguén Formation. Miocene plutonic rocks of the North Patagonian Batholith intruded these metasedimentary rocks, generating a contact metamorphic aureole that reaches biotite grade and overprints a previous metamorphic fabric probably formed during closure of the Traiguén Basin. Similar young ages for metamorphic rocks located immediately west of the Liquiñe-Ofqui Fault Zone 300 km north, near Ayacara, suggest a regional pattern of earliest Neogene metamorphism and rapid exhumation in this segment of the Patagonian Andes.

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Constraints on the Neogene growth of the central Patagonian Andes at the latitude of the Chile triple junction (45–47°S) using U/Pb geochronology in synorogenic strata

Abstract: Constraints on the Neogene growth of the central Patagonian Andes at the latitude of the Chile triple junction (45-47°S) using U/Pb geochronology in synorogenic strata. Tecto (2018),

Cited by 41 publications

References 78 publications

The role of slab geometry in the exhumation of cordilleran-type orogens and their forelands: Insights from northern Patagonia

The role of slab geometry in the exhumation of cordilleran-type orogens and their forelands: Insights from northern Patagonia

Cretaceous-Cenozoic growth of the Patagonian broken foreland basin, Argentina: Chronostratigraphic framework and provenance variations during transitions in Andean subduction dynamics

Mid-Cenozoic SHRIMP U-Pb detrital zircon ages from metasedimentary rocks in the North Patagonian Andes of Aysén, Chile

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