Ordovician metamorphism and plutonism in the Sierra de Quilmes metamorphic complex: Implications for the tectonic setting of the northern Sierras Pampeanas (NW Argentina)

Büttner, Steffen H.; Glodny, Johannes; Lucassen, Friedrich; Wemmer, Klaus; Erdmann, Saskia; Handler, Robert; Franz, Gerhard

doi:10.1016/j.lithos.2005.01.006

Cited by 96 publications

(149 citation statements)

References 65 publications

Supporting

Mentioning

131

Contrasting

Unclassified

Order By: Relevance

“…The protoliths were mainly turbiditic sediments of the Puncoviscana Formation (Toselli 1990;Toselli and Rossi de Toselli 1990). Büttner et al (2005) calculated an Ordovician age for the metamorphic peak.…”

Section: Main Geological Features Of Other Basement Blocks In the Easmentioning

confidence: 99%

“…Banded schist from the Sierras de Chepes yielded detrital ages between 540 and 511 Ma with an average of 525 Ma (Drobe et al 2010 this volume). Büttner et al (2005) proposed that for the Sierra de Quilmes metamorphic complex the metamorphic peak in migmatites and calc-silicate rocks is at or slightly prior to *470 Ma.…”

Section: Time Constraints For the Famatinian Metamorphismmentioning

confidence: 99%

“…In the Sierra de Quilmes, Famatinian magmatism is represented by the composite peraluminous to metaluminous granitoids of the Cafayate pluton (Büttner et al 2005). …”

Section: Ediacaran To Cambrian Granitoidsmentioning

confidence: 99%

See 2 more Smart Citations

The Neoproterozoic-early Paleozoic metamorphic and magmatic evolution of the Eastern Sierras Pampeanas: an overview

Steenken¹,

Luchi

Dopico

et al. 2010

Int J Earth Sci (Geol Rundsch)

View full text Add to dashboard Cite

The Eastern Sierras Pampeanas were structured by three main events: the Ediacaran to early Cambrian (580-510 Ma) Pampean, the late Cambrian-Ordovician (500-440 Ma) Famatinian and the Devonian-Carboniferous (400-350 Ma) Achalian orogenies. Geochronological and Sm-Nd isotopic evidence combined with petrological and structural features allow to speculate for a major rift event (Ediacaran) dividing into two Mesoproterozoic major crustal blocks (source of the Grenvillian age peaks in the metaclastic rocks).This event would be coeval with the development of arc magmatism along the eastern margin of the eastern block. Closure of this eastern margin led to a Cambrian active margin (Sierra Norte arc) along the western margin of the eastern block in which magmatism reworked the same crustal block. Consumption of a ridge segment (input of OIB signature mafic magmas) which controlled granulite-facies metamorphism led to a final collision (Pampean orogeny) with the western Mesoprotrozoic block. Sm-Nd results for the metamorphic basement suggest that the T DM age interval of 1.8-1.7 Ga, which is associated with the less radiogenic values of eNd (540) (-6 to -8), can be considered as the mean average crustal composition for the Eastern Sierras Pampeanas. Increasing metamorphic grade in rocks with similar detrital sources and metamorphic ages like in the Sierras de Córdoba is associated with a younger T DM age and a more positive eNd (540) value. Pampean pre-540 Ma granitoids form two clusters, one with T DM ages between 2.0 and 1.75 Ga and another between 1.6 and 1.5 Ga. Pampean post-540 Ma granitoids exhibit more homogenous T DM ages ranging from 2.0 to 1.75 Ga. Ordovician re-activation of active margin along the western part of the block that collided in the Cambrian led to arc magmatism (Famatinian orogeny) and related ensialic back-arc basin in which high-grade metamorphism is related to mid-crustal felsic plutonism and mafic magmatism with significant contamination of continental crust. T DM values for the Ordovician Famatinian granitoids define a main interval of 1.8-1.6, except for the Ordovician TTG suites of the Sierras de Córdoba, which show younger T DM ages ranging from 1.3 to 1.0 Ga. In Devonian times (Achalian orogeny), a new subduction regime installed west of the Eastern Sierras Pampeanas. Devonian magmatism in the Sierras exhibit process of mixing/assimilation of depleted mantle signature melts and continental crust. Achalian magmatism exhibits more radiogenic eNd (540) values that range between 0.5 and -4 and T DM ages younger than 1.3 Ga. In pre-Devonian times, crustal reworking is dominant, whereas processes during Devonian times involved different geochemical and isotopic signatures that reflect a major input of juvenile magmatism.

show abstract

Section: Main Geological Features Of Other Basement Blocks In the Easmentioning

confidence: 99%

Section: Time Constraints For the Famatinian Metamorphismmentioning

confidence: 99%

See 1 more Smart Citation

The Neoproterozoic-early Paleozoic metamorphic and magmatic evolution of the Eastern Sierras Pampeanas: an overview

Steenken¹,

Luchi

Dopico

et al. 2010

Int J Earth Sci (Geol Rundsch)

View full text Add to dashboard Cite

show abstract

“…There is general agreement about the Early Ordovician age for the magmatism and metamorphic peaks in the Cachi region and neighbour areas (Lork et al, 1989;Lork y Bahlburg, 1993;Büttner et al, 2005;Haschke et al, 2005;Viramonte et al, 2007;Einhorn, 2010;Sola et al, 2010;Pearson et al, 2012), but discrepancies still subsist concerning the relationing at the base of the continental crust by huge amounts of mantle-derived magmas.…”

Section: Discussionmentioning

confidence: 97%

“…With a few exceptions (Rossi et al, 1992;Büttner et al, 2005), the geological evolution of the Cachi ranges is related to a protracted contraction linked to a long lasting subduction event encompassing the Pampean and Famatinian orogenic cycles (Lucassen and Becchio 2003;Pearson et al, 2012). However, from the regional point of view and based mainly on stratigraphic analyses of the Ordovician basins, Bahlburg (1990), Balhburg and Hervé (1997), Astini (2008) and Coira et al (2009), among others, proposed a Early Ordovician extensional back-arc followed by a contractional event from the Middle-Late Ordovician for the evolution of the Ordovician basins of the Central Andes (Ocloyic orogeny).…”

Section: W E P U N C O V Is C a N A Fo Rm A Ti O N S C H Is T M Ig M mentioning

confidence: 99%

The Sierra de Cachi (Salta, NW Argentina): geological evidence about a Famatinian retro-arc at mid crustal levels

Hongn¹,

Tubía²,

Esteban³

et al. 2014

Journal of Iberian Geology

View full text Add to dashboard Cite

The Cachi mountain ranges, located in Salta (NW Argentina), form an inlier where Neoproterozoic and Paleozoic materials of the Andes crop out in a plutono-metamorphic dome surrounded by Mesozoic and Cenozoic sedimentary rocks. The pre-Mesozoic rocks record a regional metamorphism of low pressure and high temperature conditions, which reached partial melting conditions and was coeval with the intrusion of sheeted granite and trondhjemite plutons. The metamorphic evolution and the emplacement of the plutons took place in an extensional tectonic setting. New U-Pb zircon dating by TIMS and SHRIMP methods yields similar ages for the migmatization (479.7 ± 3.5 Ma) and the emplacement of granites (472.1 ± 11 Ma), constraining the extensional event to Early Ordovician times. We also report the finding of gabbro boulders, which also yield a similar U-Pb SHRIMP zircon age of 477.5 ± 3.9 Ma. So, we propose that the extensional event recognized in Sierra de Cachi took place in a retro-arc setting linked to the Famatinian subduction along the western border of Gondwana. The shortening produced by younger east-verging folds evidences the superposition of a compressional stress field, probably related with the Ocloyic orogeny (Middle/Late Ordovician-Devonian).Keywords: U-Pb geochronology, Famatinian retro-arc, Cachi ranges, Argentina Resumen En la Sierra de Cachi, situada en Salta (NO de Argentina), afloran rocas neoproterozoicas y paleozoicas de los Andes en un domo plutono-metamórfico flanqueado por rocas sedimentarias mesozoicas y cenozoicas. Estas rocas registran un metamorfismo de alta temperatura y baja presión, que alcanzó condiciones de fusión parcial y fue coetáneo del emplazamiento de plutones de granitos y trondhjemitas. El metamorfismo y el emplazamiento de los plutones se produjo en condiciones extensionales. Nuevos análisis de U-Pb en zircones, por los métodos TIMS y SHRIMP, proporcionan edades similares para la migmatización (479,7 ± 3,5 Ma) y el emplazamiento de los granitos (472,1 ± 11 Ma), acotando el evento extensional al Ordovícico Inferior. También describimos el hallazgo de bloques de gabros que dan una edad U-Pb SHRIMP en circones semejante, de 477,5 ± 3,9 Ma. Por lo tanto, se propone que el evento extensional descrito en la Sierra de Cachi tuvo lugar en una zona de retro-arco asociada a la subducción famatiniana del borde occidental de Gondwana. El acortamiento producido por los pliegues más jóvenes vergentes al E refleja la superposición de un campo de esfuerzos compresivos, probablemente relacionados con la orogenia Oclóyica (Ordovícico Medio/Superior-Devónico).Palabras clave: geocronología U-Pb, retro-arco famatiniano, Sierra de Cachi, Argentina

show abstract

Multiple migmatite events and cooling from granulite facies metamorphism within the Famatina arc margin of northwest Argentina

et al. 2014

View full text Add to dashboard Cite

The Famatina margin records an orogenic cycle of convergence, metamorphism, magmatism, and extension related to the accretion of the allochthonous Precordillera terrane. New structural, petrologic, and geochronologic data from the Loma de Las Chacras region demonstrate two distinct episodes of lower crustal migmatization. The first event preserves a counterclockwise pressure-temperature path in kyanite-K-feldspar pelitic migmatites that resulted in lower crustal migmatization via muscovite dehydration melting at ∼12 kbar and 868 • C at 461 ± 1.7 Ma. The shape of the pressure temperature path and timing of metamorphism are similar to those of regional midcrustal granulites and suggest pervasive Ordovician migmatization throughout the Famatina margin. One-dimensional thermal modeling coupled with regional isotopic data suggests Ordovician melts remained at temperatures above their solidus for 20-30 Ma following peak granulite facies metamorphism, throughout a time period marked by regional oblique convergence. The onset of synconvergent extension occurred only after regional migmatites cooled beneath their solidus and was synchronous with the cessation of Precordillera terrane accretion at ∼436 Ma. The second migmatite event was regionally localized and occurred at ∼700 • C and 12 kbar between 411 and 407 Ma via vapor saturated melting of muscovite. Migmatization was synchronous with extension, exhumation, and strike-slip deformation that likely resulted from a change in the plate boundary configuration related to the convergence and collision of the Chilenia terrane.

show abstract

Ordovician metamorphism and plutonism in the Sierra de Quilmes metamorphic complex: Implications for the tectonic setting of the northern Sierras Pampeanas (NW Argentina)

Cited by 96 publications

References 65 publications

The Neoproterozoic-early Paleozoic metamorphic and magmatic evolution of the Eastern Sierras Pampeanas: an overview

The Neoproterozoic-early Paleozoic metamorphic and magmatic evolution of the Eastern Sierras Pampeanas: an overview

The Sierra de Cachi (Salta, NW Argentina): geological evidence about a Famatinian retro-arc at mid crustal levels

Multiple migmatite events and cooling from granulite facies metamorphism within the Famatina arc margin of northwest Argentina

Contact Info

Product

Resources

About