The Late Triassic Central Patagonian Batholith: Magma hybridization, 40Ar/39Ar ages and thermobarometry

Zaffarana, Claudia Beatriz; Somoza, Rubén; Luchi, Mónica López de

doi:10.1016/j.jsames.2014.06.006

Cited by 32 publications

(34 citation statements)

References 57 publications

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“…1B). The CPB is primarily comprised of diorites to granites of the older Gastre superunit, which are in turn intruded by the granites of the Lipetrén superunit (Rapela et al, 1991Zaffarana et al, 2014).…”

Section: Geological Settingmentioning

confidence: 99%

Section: Geological Settingmentioning

confidence: 99%

“…The oldest unit of the Gastre superunit comprises equigranular hornblende-biotite granodiorites (Zaffarana et al, 2014). These granodiorites pass gradually to porphyritic biotite-hornblende monzogranites (Zaffarana et al, 2014). Another unit in the Gastre superunit is composed of equigranular biotitic monzogranites, which form stocks of light pink, medium-to coarse-grained equigranular monzogranites that intrude both the equigranular hornblende-biotite granodiorites and the porphyritic biotite-hornblende monzogranites (Zaffarana et al, 2014).…”

Section: Geological Settingmentioning

confidence: 99%

“…The Central Patagonian batholith (CPB; Fig. 1A; Rapela et al, 1991Zaffarana et al, 2014) is a suite of Late Triassic calcalkaline plutons that rep-resents a key element in paleogeographic models of pre-Gondwana breakup, as it was emplaced during the transition between the Gondwanide (late Paleozoic) and the Andean (Jurassic to present) tectonic cycles in South America. The emplacement of the CPB has been inferred as syntectonic with the activity of the Gastre fault system, a controversial NW-SE subvertical structure that has been conceived as a major dextral fault cross-cutting Patagonia ( Fig.…”

Section: Introductionmentioning

confidence: 99%

“…Furthermore, local mesoscale geological observations in the type locality of the Gastre fault system argue against the idea that the CPB has been affected by continental-scale Jurassic dextral shearing (von Gosen and Loske, 2004;Zaffarana et al, 2010Zaffarana et al, , 2014. However, a comprehensive structural characterization of the CPB has remained a pending task.…”

Section: Introductionmentioning

confidence: 99%

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Internal structure of the Late Triassic Central Patagonian batholith at Gastre, southern Argentina: Implications for pluton emplacement and the Gastre fault system

Zaffarana

2017

Geosphere

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The Central Patagonian batholith (CPB) comprises two Late Triassic calcalkaline plutonic suites (the Gastre superunit of 221 ± 2 Ma and the Lipetrén superunit of 215 ± 1 Ma) which have been interpreted as a record of major dextral motion along the transcontinental NW-SE-striking subvertical Gastre fault system in Jurassic times. We performed a detailed study of the internal structure of the CPB through structural and anisotropy of magnetic susceptibility (AMS) techniques. The Gastre superunit reveals a very consistent pattern of NW-SE-striking steeply dipping magmatic foliations. Tectonic fabrics within the CPB are scarce and generally parallel to the magmatic fabrics. The magmatic and solid-state lineations within the CPB are steeply, intermediately, or shallowly plunging. The combination of flattened magmatic and solid-state fabrics with subvertical orientations and with steep to shallow lineations, together with the kinematic indicators in two mylonite belts with suspected CPB protoliths, suggests that the Gastre superunit was emplaced within a sinistral transpressive regime. The shallower stocks of the Lipetrén superunit are more isotropic and have magmatic fabrics associated with magma chamber dynamics. The deformation of the CPB is coaxial with the late Paleozoic deformation in the hosting Calcatapul Formation. The late Paleozoic deformation in the North Patagonian Massif generated widespread NW-SE subvertical fractures which could have aided the emplacement of the CPB. The internal structure of the CPB does not support a model of dextral strike-slip movements on major Jurassic faults.

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Section: Geological Settingmentioning

confidence: 99%

Section: Geological Settingmentioning

confidence: 99%