Geochronology of metamorphic and eruptive rocks of southeastern Neuquén and northwestern Río Negro Provinces, Argentine Republic

Linares, Edlaine; Cagnoni, Mariana Celina; Campo, Margarita Do; Ostera, Héctor A.

doi:10.1016/0895-9811(88)90015-6

Cited by 24 publications

(23 citation statements)

References 10 publications

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“…Linares et al, 1997;López de Luchi et al, 2000) and the areas of Comallo and Paso Flores (Varela et al, 1999), which are located more than 150 km northwest of Gastre. These ages suggest that the Mamil Choique Formation intrusions, at least in parts, are Late Paleozoic (Permian) in age, as is also supported by the dating of the granites at Río Collón Curá (Linares et al, 1988).…”

Section: Lithological Unitssupporting

confidence: 61%

Tectonic history of the Calcatapul Formation, Chubut province, Argentina, and the “Gastre fault system”

Gosen

Loske²

2004

Journal of South American Earth Sciences

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Section: Lithological Unitssupporting

confidence: 61%

Tectonic history of the Calcatapul Formation, Chubut province, Argentina, and the “Gastre fault system”

Gosen

Loske²

2004

Journal of South American Earth Sciences

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“…This was also supported by Rb-Sr and K-Ar dates from different rock types in the western and southwestern part of the North Patagonian Massif (e.g. Linares et al 1988Linares et al , 1997Ostera et al 2001). Duhart, Haller & Hervé (2002), however, have shown the existence of a diamictite in the succession, similar to those of the upper Palaeozoic sedimentary rocks of the Esquel basin, which then could be late Palaeozoic in age.…”

Section: Lithological Unitsmentioning

confidence: 70%

“…The dates can be related to a closure of the K-Ar system due to a cooling process that might have been combined with a regional uplift (see Varela et al 1999). A K-Ar biotite age from an aplite (245 ± 10 Ma: Linares et al 1988) and a muscovite age from an aplitic granite (244 ± 7 Ma: Varela et al 2005) north of Río Limay fall in the same time interval.…”

Section: Ages Of Eventsmentioning

confidence: 92%

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.

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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.

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“…The preliminary Rb-Sr date of 850^50 Ma reported from the Mina Gonzalito gneiss in the North Patagonian Massif (Linares et al, 1990) was later invalidated by another U-Pb date of 526 Ma . In the western region of the North Patagonian Massif, preliminary ages, Rb-Sr isochrons and errorchrons of up to 860 Ma (Parica, 1986;Dalla Salda et al, 1991a,b), or even the Rb-Sr reference isochron of 1190^16 Ma (Linares et al, 1988) could not be confirmed by other methods like UPb, which yielded Late Paleozoic dates Varela et al, 1999).…”

Section: Regional Implicationsmentioning

confidence: 97%

The Las Matras tonalitic–trondhjemitic pluton, central Argentina: Grenvillian-age constraints, geochemical characteristics, and regional implications

Sato

Tickyj

Llambías

et al. 2000

Journal of South American Earth Sciences

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The N-S trending belt with Grenvillian-age rocks developed in central western Argentina represents the basement of an allochthonous terrane derived from Laurentia during the Early Paleozoic. The Las Matras pluton (36Њ46 H S, 67Њ07 H W) is located at the southern extension of this belt in the Las Matras Block. It consists of a low-Al tonalitic to trondhjemitic facies characteristic of an arc magmatism. Isotopic studies yielded Grenvillian Rb-Sr (1212^47 Ma) and Sm-Nd (1188^47 Ma) ages which, due to the undeformed and non-metamorphosed character of the pluton, are interpreted to represent a crystallization age of around 1200 Ma. Although this age is slightly older than available dates from other exposures of the same belt, and the undeformed feature is also distinctive for Las Matras, the depleted Sr and Nd isotopic signatures of the pluton agree with those from other magmatic rocks involved in that belt. The differences found between Las Matras and the northern exposures indicate that this belt with Grenvillian-age rocks comprises regions of non-homogeneous evolution. Although the correlation of the Lower Paleozoic platform carbonates from the sedimentary cover of the Grenvillian-age basement rocks suggests the surroundings of the Southern Grenville Province (Texas and northern Mexico) as the probable detachment site for the Argentine belt, comparison of magmatic and tectonic processes involved in these basement rocks does not indicate similar evolutions. This fact can suggest an independent evolution of the Argentine belt prior to amalgamation to the Laurentian Grenville orogen. ᭧

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Geochronology of metamorphic and eruptive rocks of southeastern Neuquén and northwestern Río Negro Provinces, Argentine Republic

Cited by 24 publications

References 10 publications

Tectonic history of the Calcatapul Formation, Chubut province, Argentina, and the “Gastre fault system”

Tectonic history of the Calcatapul Formation, Chubut province, Argentina, and the “Gastre fault system”

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

The Las Matras tonalitic–trondhjemitic pluton, central Argentina: Grenvillian-age constraints, geochemical characteristics, and regional implications

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