Detrital-zircon geochronology of the eastern Magallanes foreland basin: Implications for Eocene kinematics of the northern Scotia Arc and Drake Passage

Barbeau, David L.; Olivero, Eduardo B.; Swanson‐Hysell, Nicholas L.; Zahid, Khandaker M.; Murray, Kendra E.; Gehrels, George E.

doi:10.1016/j.epsl.2009.05.014

Cited by 111 publications

(94 citation statements)

References 66 publications

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“…3a). Consistent with this view, detrital zircon compositions from Tierra del Fuego (Barbeau et al, 2009;Hervé et al, 2010) show that the Paleozoic metasediments there accumulated in sedimentological communication with the interior of Gondwana. Basement rocks in Graham Land may be similar (Millar et al, 2002), consistent with it forming a northwestern continuation of this rim as shown.…”

Section: Basementsupporting

confidence: 62%

South Georgia and Gondwana's Pacific Margin: Lost in translation?

Eagles

2010

Journal of South American Earth Sciences

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Section: Basementsupporting

confidence: 62%

South Georgia and Gondwana's Pacific Margin: Lost in translation?

Eagles

2010

Journal of South American Earth Sciences

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“…Evidence in support of this interpretation includes the following: a. the notable angular unconformity between the Leticia and Punta Torcida Formation (Torres Carbonell et al, 2008a;Torres Carbonell and Olivero, 2012), which involves a hiatus of ~4 Ma (Olivero and Malumian, 1999;Olivero and Malumián, 2008;Barbeau et al, 2009;Torres Carbonell et al, 2009); b. the wedging of the Leticia Formation against an uplifted paleotopography coinciding with the structural high Torres Carbonell et al, 2008a;Torres Carbonell, 2010); and c. the exposure of part of that high, comprising a narrow belt parallel to the TFB (E-W) where the Punta Torcida Formation crops out extensively, with deformation suggesting localized shortening and uplift of the unit (Figs. 2B and 9) (Torres Carbonell et al, 2008a).…”

Section: Eastern Area (Outcrop Data)mentioning

confidence: 99%

Evaluación de variaciones en el grado de deformación y el estilo estructural a lo largo del frente de la faja corrida y plegada Fueguina, Argentina.

Carbonell

Dimieri

Olivero

2013

Andgeo

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ABSTRACT. The Fuegian thrust-fold belt (TFB) forms the thin-skinned outer wedge of the Andes in Tierra del Fuego. Using subsurface and outcrop data from two areas (Western and Eastern) of the TFB front in Argentina we aimed to verify and characterize the apparent structural variations along the strike. Both areas reveal pro-and retro-vergent faultrelated folds detached at similar horizons, with a youngest early to middle (?) Miocene deformation age. However, the Western Area has gentle, large-wavelength folds whereas the Eastern Area is characterized by a very tight structural geometry, with closer fold geometries. This difference manifests itself in the shortening of analogous structures: below 5.5% in the west as against ~22% in the Eastern Area. Our findings verify structural style variations along the strike and suggest that the Eastern Area endured higher strain. We evaluate two possible causes of this strain gradient, assuming homogeneous regional shortening: (i) lateral rheological variations at the base of the thrust wedge, namely the occurrence of more competent beds which would have restrained the propagation of the detachment toward the east; and (ii) the effect of strong buttressing in the eastern TFB exerted by the Río Chico arch basement promontory during deformation. Published results, together with our current subsurface and outcrop data, rule out significant rheological gradients in a preferred direction along the TFB. On the other hand, we present evidence of the nucleation of frontal thrusts above basement steps at the Río Chico arch western margin, which comprise local buttresses. We speculate that this buttressing was mantained along the TFB front and is enhanced toward the east, where forward TFB propagation was hindered due to the southern projection of the Río Chico promontory. This would explain the higher strain and more complex structural style in the Eastern Area. 439Torres Carbonell et al. / Andean Geology 40 (3): 438-457, 2013 RESUMEN. Evaluación de variaciones en el grado de deformación y el estilo estructural a lo largo del frente de la faja corrida y plegada Fueguina, Argentina. La faja corrida y plegada Fueguina (FCP) comprende el cinturón de piel fina en el antepaís de los Andes en Tierra del Fuego. Con la finalidad de verificar y caracterizar posibles variaciones estructurales a lo largo del frente de la FCP en Argentina, hemos analizado datos de subsuelo y superficie en dos áreas (occidental y oriental). Ambas revelan pliegues relacionados con fallas, tanto provergentes como retrovergentes, que despegan en niveles similares, y tienen una edad mínima miocena temprana a media (?). Sin embargo, en el área occidental el plegamiento es suave y de alta longitud de onda mientras que en el área oriental la estructura es muy apretada, con pliegues más cerrados. Esta diferencia se manifiesta al comparar el acortamiento en estructuras análogas: menor a 5,5% en el oeste contra ~22% en el área oriental. Por lo tanto, queda verificada la existencia de variaciones en el estilo estructur...

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“…The youngest U-Pb ages of zircon in populations of detrital zircon are commonly used to constrain maximum depositional ages of stratigraphic units (e.g., Dickinson and Gehrels, 2009 and references therein), but there is lack of consensus about the methods to do so (Barbeau et al, 2009). Thus, we use four alternate measures of the youngest age which vary from least to most statistically robust as follows: (a) youngest single grain age, (b) youngest graphic peak controlled by more than one grain age, (c) weighted mean age of the youngest three or more grains that overlap at ±2σ (d) weighted mean age of all grains that correspond to the youngest peak ( The U-Pb zircon ages obtained for intrusive rocks emplaced within the schists are of 278.3±5.8 Ma for granite (CHY-83) of the del Carrizo creek and of 285.7±6.8 for foliated tonalite (CHY-19a) of the Jardín creek (Fig.…”

Section: Resultsmentioning

confidence: 99%

Geocronología U-Pb de circones detríticos del Complejo Metamórfico Quebrada del Carrizo y Esquistos El Jardín y granitoides espacialmente relacionados del Batolito Sierra Castillo.

Maksaev

Arancibia

Munizaga

et al. 2015

Andgeo

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ABSTRACT. U-Pb detrital-zircon geochronology of two discrete outcrops of mica schists of the western border of the Domeyko Cordillera in the Region of Atacama, northern Chile, indicates that the maximum age of sedimentation of their protolith corresponds to the Late Carboniferous to Early Permian. The Early Permian granitoids of the Sierra Castillo Batholith that intruded the metamorphic rocks show ductile deformation and were emplaced within hot crust not much later than the greenschist-facies metamorphism peak that affected their host rocks. Therefore, the metamorphism of the Quebrada del Carrizo Metamorphic Complex and El Jardín Schists is constrained temporarily between the maximum age of sedimentation of detrital zircons (314±11 to 291±5 Ma) and the crystallization of Early Permian intrusions (292.2±6.6 to 278.3±5.8 Ma), thus pointing to Early Permian metamorphic peak. Concentration of U-Pb ages between 400 and 600 Ma indicate eastern detrital input sources, such as the Pampean and Brasiliano orogenies and the Ordovician-Silurian Famatinian magmatic arc of northwestern Argentina. Other concentration of detrital-zircon U-Pb ages between 900 to 1,200 Ma reflect contributions of magmatic rocks of age of the Proterozoic Sunsas orogeny (Grenville). Whereas, only few grains of zircon with U-Pb ages older than 1,200 Ma occur and these may correspond to a minor contribution zircon from South American cratonic areas. Zircon grains of Devonian age are scarce in populations of zircons analyzed, consistent with a passive margin and a lull of magmatic activity during this period in the paleo-Pacific border of Gondwana. The U-Pb detrital zircon data from the Quebrada del Carrizo Metamorphic Complex and El Jardín Schists coincide with detritalzircon U-Pb data previously published for other metamorphic complexes of central-northern Chile, which are part of a Late Paleozoic subduction complex or accretionary wedge developed in the western edge of Gondwana. Consequently, the Quebrada del Carrizo Metamorphic Complex and El Jardín Schists are relics of the same Paleozoic accretionary wedge, which constituted the substratum for the emplacement of the Permian plutons of the Sierra Castillo Batholith.

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Detrital-zircon geochronology of the eastern Magallanes foreland basin: Implications for Eocene kinematics of the northern Scotia Arc and Drake Passage

Cited by 111 publications

References 66 publications

South Georgia and Gondwana's Pacific Margin: Lost in translation?

South Georgia and Gondwana's Pacific Margin: Lost in translation?

Evaluación de variaciones en el grado de deformación y el estilo estructural a lo largo del frente de la faja corrida y plegada Fueguina, Argentina.

Geocronología U-Pb de circones detríticos del Complejo Metamórfico Quebrada del Carrizo y Esquistos El Jardín y granitoides espacialmente relacionados del Batolito Sierra Castillo.

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