Cenozoic crustal thickening, wrenching and rifting in the foothills of the southernmost Andes

Diraison, Marc; Cobbold, P.R.; Gapais, Denis; Rossello, Eduardo A.; Corre, C. Le

doi:10.1016/s0040-1951(99)00255-3

Cited by 110 publications

(115 citation statements)

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“…7). A similar pattern is inferred from the shortening directions obtained from fault kinematic analyses by Diraison et al (2000). According to these authors, the shortening directions (based on the measurement of 1600 striated fault …”

Section: Accepted M Manuscriptsupporting

confidence: 70%

“…The first sedimentary infill of the marginal basin is represented by the Upper Jurassic to Lower Cretaceous submarine silicic volcanics and volcaniclastic levels of the Tobifera (or Lemaire) formation, and dark mudstones of the Yahgan (or Zapata) formation, followed by slope mudstones of the Beauvoir Formation (Wilson, 1991;Fildani and Hessler, 2005;Olivero and Malumián, 2008;Menichetti et al, 2008;Klepeis et al, 2010). In the Early Cretaceous, the opening of the South Atlantic Ocean associated with increased subduction rates along the Pacific margin (Rabinowitz and LaBrecque, 1979;Dalziel, 1986;Ramos, 1989;Diraison et al, 2000;Somoza and Zaffarana, 2008) induced sinistral transpression along the southwestern margin of South America Klepeis, 1994).…”

Section: Accepted M Manuscriptmentioning

confidence: 99%

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Constraints on deformation of the Southern Andes since the Cretaceous from anisotropy of magnetic susceptibility

et al. 2015

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Section: Accepted M Manuscriptsupporting

confidence: 70%

Section: Accepted M Manuscriptmentioning

confidence: 99%

Constraints on deformation of the Southern Andes since the Cretaceous from anisotropy of magnetic susceptibility

et al. 2015

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“…A major tectonic event was the widespread extensional regime in the Late Jurassic that led to formation of the Rocas Verdes marginal basin (RVB) along the southern Patagonian and Fuegian continental margin (Dalziel et al, 1974;Suárez and Pettigrew, 1976;Hanson and Wilson, 1991;Calderón et al, 2007). In the Late Cretaceous, compression in the Pacific margin of the South American plate led to the closure and inversion of the basin and the development of the Andean orogen with its associated fold-and-thrust belt (Dalziel et al, 1974;Wilson, 1991;Bruhn, 1979;Nelson et al, 1980;Diraison et al, 2000;Kraemer, 2003;Menichetti et al, 2008). Since the Paleocene, in correspondence with the expansion of the Weddell Sea between South America and Antarctica, the formation of the small Scotia plate produced a strike-slip tectonic regime along the Fuegian Andes (Cunningham, 1993(Cunningham, , 1995.…”

Section: Geological Framework Of the Southernmost Andesmentioning

confidence: 99%

“…The main Cordillera and the Magallanes fold-and-thrust belt are affected by a strike-slip fault system. Wrench tectonics affected the region during the Andean compressional phase and especially from the Oligocene onwards (e.g., Bruhn, 1979;Klepeis, 1994;Cunningham, 1995;Diraison et al, 2000;Lodolo et al, 2001;Menichetti et al, 2008 and references therein).…”

Section: Introductionmentioning

confidence: 99%

Fabrica Magnetica y Microestructuras a traves de los Andes de Tierra del Fuego, Argentina.

Esteban

Tassone

Menichetti

et al. 2011

Andgeo

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ABSTRACT. An anisotropy of magnetic susceptibility (AMS) transect was carried out across the Fuegian Andes, in Argentina, with the aim of studying its tectonic evolution. Two-hundred and forty oriented samples were collected from 27 sites distributed between the Paso Garibaldi to the north and the Canal Beagle to the south. The study was restricted to the Upper Jurassic Lemaire Formation, with a single site located in the Lower Cretaceous Yahgán Formation. Studied rocks comprised basaltic, andesitic, volcaniclastic and sedimentary rocks affected by low-grade metamorphism. AMS measurements were complemented with thin section analyses of representative samples in order to characterize the microstructures and metamorphic assemblages. In general, the magnetic fabric shows dominant oblate shapes and a large variation in the anisotropy degree from 1.04 up to 2. The anomalously high values were observed to be associated to growth of secondary pyrrhotite, which was identified by rock magnetic tests. Magnetic foliation was generally consistent with slaty cleaveage as observed in the field, confirming the tectonic origin of the magnetic fabric. Three geographic domains were distinguished in the study region on the basis of the pattern of the AMS axes distribution. In the northern domain, from Paso Garibaldi to Valle Carbajal, the orientation of the maximum susceptibility axis (k 1 ), or magnetic lineation, is N-S to NE-SW with moderate plunge towards the S-SW and coincides with previous determination of mineral lineations associated with the Andean deformation and very low grade metamorphism. The magnetic fabric pattern can be correlated with the main deformational phase responsible for the development of slaty cleavage (main Andean deformational phase) and the tectonic transport due to progression of the Fuegian fold and thrust belt in the Late Cretaceous. A different character is shown along the Valle Carbajal domain, where subvertical E-W magnetic foliation planes and roughly E-W to ESE-WNW subhorizontal magnetic lineations are more difficult to correlate with the main folding phase and suggest its relation to an E-W, possibly localized, strike-slip regime during the main deformational and metamorphic phase. The magnetic fabrics in the third domain, close to the Canal Beagle, displays a more heterogeneous character with both E-W and N-S striking foliations; in this case a population of subhorizontal E-W magnetic lineation (k 1 ) suggests the existence of a significant component of strike-slip deformation. Keywords: AMS, Microstructures, Mesozoic, Andean tectonics, Tierra del Fuego, Argentina. 65 Esteban et al./ Andean Geology 38 (1): 64-81, 2011 RESUMEN. Fábrica Magnética y Microestructuras a través de los Andes de Tierra del Fuego, Argentina.Se presentan los resultados de una transecta de Anisotropía de Susceptibilidad Magnética (ASM) realizada en los Andes Fueguinos, Argentina. Se midieron 240 muestras orientadas provenientes de 27 sitios de muestreo distribuidos entre Paso Garibaldi, al norte y el Canal Beagle al su...

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“…Palinspastic reconstructions correlate the Early Cretaceous back-arc basin deposits of South Georgia with those of the Rocas Verdes Marginal Basin (RVMB) in southernmost Patagonia along the former southwestern margin of Gondwana (Dalziel et al, 1975). Following closure and deformation of the RVMB during the main Andean orogeny, the South Georgia microcontinental block became tectonically displaced along the North Scotia Ridge during Cenozoic evolution of the Scotia Sea (Diraison et al, 2000;Livermore et al 2007).…”

Section: Introductionmentioning

confidence: 99%

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2007

Cooper Bay dislocation

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The Cooper Bay Dislocation Zone (CBDZ) represents a major NW-SE trending tectonic boundary within the island of South Georgia that juxtaposes components of a Middle Jurassic to mid-Cretaceous island-arc and back-arcbasin system. New detailed structural data from the southern end of the dislocation zone reveal that earliest displacement along the boundary appears to have been associated with dip-slip reverse shear, characterised by widespread proto-to meso-mylonitic granitic rocks within the basement assemblage exposed to the southwest of the shear zone. Along the northeast margin, highly sheared and mylonitised metasedimentary and metabasic rocks reveal sinistral strike-slip kinematics and a sub-horizontal mineral lineation. Narrow zones of sinistral shear are locally superimposed within the basement rocks along the SW margin, that together with the presence of brittle sinistral faults suggest that the strike-slip component of deformation postdates the dip-slip. Comparison with the tectonic history of the Rocas Verdas Marginal Basin, Fuegian Andes, suggests that the sinistral shear event preserved along the CBDZ maybe be related to Late Cretaceous, main Andean orogenic transpression, although a Cenozoic event cannot to ruled out.

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Cenozoic crustal thickening, wrenching and rifting in the foothills of the southernmost Andes

Cited by 110 publications

References 60 publications

Constraints on deformation of the Southern Andes since the Cretaceous from anisotropy of magnetic susceptibility

Constraints on deformation of the Southern Andes since the Cretaceous from anisotropy of magnetic susceptibility

Fabrica Magnetica y Microestructuras a traves de los Andes de Tierra del Fuego, Argentina.

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