The Rio Chico Paleozoic crystalline complex and the evolution of Northern Patagonia

Salda, Luis Hugo Dalla; Varela, Ricardo; Cingolani, Carlos Alberto; Aragón, Eugenio

doi:10.1016/0895-9811(94)90022-1

Cited by 46 publications

(19 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…For the former, López de Luchi et al (1999) suggest a Carboniferous Rb-Sr whole-rock age which is in support of an isotopic date of Linares et al (1997). On the contrary, early Permian U-Pb ages have been reported for a granodiorite and muscovite migmatite southwest of Mamil Choique (Varela et al 2005;Pankhurst et al 2006), a middle Permian age from a granodiorite gneiss in the Sierra del Medio (Rapela, Pankhurst & Harrison, 1992), whereas middle to late Permian ages (based on the time scale of Gradstein et al 2004) were obtained for the La Pintada leucomonzogranites (Dalla Salda et al 1994;López de Luchi et al 2000).…”

Section: Lithological Unitsmentioning

confidence: 96%

“…This is shown by the phyllitic succession northwest of Río Chico, which seems to grade over a short distance into micaschists in the east and south. A short-distance and west-to-east increase in metamorphism also occurs in the Cañadón La Angostura (Dalla Salda et al 1994;López de Luchi, 1994). These effects might be related to a variable local heat transfer from intrusions during and after the D 2 -deformation.…”

Section: A Cushamen Formation and Intercalated Intrusive Rocksmentioning

confidence: 98%

“…The different magmatics intruded the Cushamen Formation rocks and have been assigned to a wide span between the Precambrian and Late Palaeozoic (e.g. Ravazzoli & Sesana, 1977;Nullo, 1978Nullo, , 1979Proserpio, 1978;Dalla Salda et al 1994). In the Río Chico-Mamil Choique area, Dalla Salda et al (1994) created the lower Palaeozoic Río Chico Complex, comprising the Cushamen Formation and Mamil Choique Granitoids, the latter with an Ordovician Rb-Sr age, from the Devonian Viuda de Gallo and Permian La Pintada granite (Dalla Salda et al 1994).…”

Section: Lithological Unitsmentioning

confidence: 99%

“…On the other hand, Dalla Salda, , 1993 and Dalla Salda et al ( , 1994 interpreted Patagonia as having been part of South America since Early Palaeozoic times. In the new model of * E-mail: vgosen@geol.uni-erlangen.de Pankhurst et al (2005Pankhurst et al ( , 2006, however, the suture between Patagonia and Gondwana South America has been placed south of the North Patagonian Massif.…”

mentioning

confidence: 99%

“…In particular, the area of Río Chico-Mamil Choique has been the subject of several studies (e.g. Dalla Salda et al 1994;López de Luchi, 1994;Cerredo & López de Luchi, 1997, 1998López de Luchi & Cerredo, 1996;López de Luchi et al 1999. In these contributions, different lithological units are separated from each other, four deformational events with a greenschist to amphibolitefacies metamorphism in the meta-clastic succession are reported, structural and geochemical features of different intrusive rocks are characterized, and various geochronological data are related to a lower Palaeozoic or upper Palaeozoic intrusive, deformational and metamorphic history.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Stages of Late Palaeozoic deformation and intrusive activity in the western part of the North Patagonian Massif (southern Argentina) and their geotectonic implications

Gosen

2008

Geol. Mag.

View full text Add to dashboard Cite

Analyses of structures in the western part of the North Patagonian Massif (southern Argentina) suggest a polyphase evolution, accompanied by continuous intrusive activity. The first two deformations (D 1 , D 2 ) and metamorphism affected the upper Palaeozoic, partly possibly older Cushamen Formation clastic succession and different intrusive rocks. A second group of intrusions, emplaced after the second deformational episode (D 2 ), in many places contain angular xenoliths of the foliated country rocks, indicating high intrusive levels with brittle fracturing of the crust. Deformation of these magmatic rocks presumably began during (the final stage of) cooling and continued under solidstate conditions. It probably coincided with the third deformational event (D 3 ) in the country rocks. Based on published U-Pb zircon ages of deformed granitoids, the D 2 -deformation and younger event along with the regional metamorphism are likely to be Permian in age. An onset of the deformational and magmatic history during Carboniferous times, however, cannot be excluded. The estimated ∼ W-E to NE-SW compression during the D 2 -deformation, also affecting the first group of intrusive rocks, can be related to subduction beneath the western Patagonia margin or an advanced stage of collisional tectonics within extra-Andean Patagonia. The younger ∼ N-S to NE-SW compression might have been an effect of oblique subduction in the west and/or continuing collision-related deformation. As a cause for its deviating orientation, younger block rotations during strike-slip faulting cannot be excluded. The previous D 2 -event presumably also had an effect on compression at the northern Patagonia margin that was interpreted as result of Patagonia's late Palaeozoic collision with the southwestern Gondwana margin. With the recently proposed Carboniferous subduction and collision south of the North Patagonian Massif, the entire scenario might suggest that Patagonia consists of two different pieces that were amalgamated with southwestern Gondwana during Late Palaeozoic times.

show abstract