Episodic and short-lived granitic pulses in a post-collisional setting: evidence from precise U–Pb zircon dating through a crustal cross-section in Corsica

Paquette, Jean‐Louis; Ménot, René-Pierre; Pin, Christian; Orsini, Jean-Baptiste

doi:10.1016/s0009-2541(02)00401-1

Cited by 133 publications

(117 citation statements)

References 26 publications

Supporting

Mentioning

105

Contrasting

Order By: Relevance

“…The PSG yields the less evolved isotopic composition with ( 87 Sr/ 86 Sr) 299 between 0.7044 and 0.7050 and εNd 299 = −2.0. These granites are significantly less radiogenic in Sr but more radiogenic in Nd than most of the Variscan granitoid rocks of Iberian Peninsula as well as most of the European Variscan granites (Cuesta, 1991;Schaltegger and Corfu, 1992;Cocherie et al, 1994;Forster et al, 1999;Paquette et al, 2003 and references therein). However, we must note that the post-D 3 granites from Northern Portugal, all have a weakly evolved isotopic composition (Silva and Neiva, 2004;Mendes and Dias, 2004).…”

Section: Isotopic Datamentioning

confidence: 98%

Genesis and emplacement of felsic Variscan plutons within a deep crustal lineation, the Penacova-Régua-Verín fault: An integrated geophysics and geochemical study (NW Iberian Peninsula)

Martins

Sant'Ovaia

Noronha

2009

Lithos

View full text Add to dashboard Cite

Multidisciplinary studies integrating, U-Pb geochronology, whole-rock geochemical data, isotope geochemistry, anisotropy of magnetic susceptibility (AMS) studies and gravimetry were carried out on the Vila Pouca de Aguiar and the Águas Frias-Chaves porphyritic biotite granite plutons. Both plutons occur independently in a distance of about 20 km. The Vila Pouca de Aguiar and Águas Frias-Chaves plutons are examples of late to post-orogenic felsic Variscan granites in northern Portugal (NW Iberian Peninsula). The U-Pb zircon analyses yield a consistent age of 299 ± 3 Ma which is considered to be the emplacement age of the two plutons. These granites are weakly peraluminous, show high HREE and Y (and low P) contents which are consistent with them being I-type. This is also supported by their weakly evolved isotopic compositions, 87 Sr/ 86 Sr i = 0.7044-0.7077 and εNd = − 2.0 to − 2.6, as well as by the whole rock oxygen isotope (δ 18 O VSMOW) ranging from + 9.7‰ to + 11.0‰. The emplacement of granite magma took place after the third Variscan deformation phase (D 3 ) in an extensional tectonic regime, large scale uplift and crustal thinning. The integration of different data suggests that both plutons have the same feeding zone aligned within the Penacova-Régua-Verin fault (PRVF) and that both have the same structure which is related to late Variscan phases. The thicker shape for the Águas Frias-Chaves pluton comparing to that of the Vila Pouca de Aguiar pluton is compatible with different depths of PRVF sectors. The available data led us to propose a model of partial melting of a meta-igneous lower crustal source rather than an open-system of mantle-crust interaction. The interaction between the continental crust and invading mafic magmas could have been limited to mere heat transfer and, perhaps, local intermingling.

show abstract

Section: Isotopic Datamentioning

confidence: 98%

Genesis and emplacement of felsic Variscan plutons within a deep crustal lineation, the Penacova-Régua-Verín fault: An integrated geophysics and geochemical study (NW Iberian Peninsula)

Martins

Sant'Ovaia

Noronha

2009

Lithos

View full text Add to dashboard Cite

show abstract

“…Metamorphic rocks are widely intruded by a network of late Variscan plutons belonging to the Corsica-Sardinia Batholith (Rossi & Cocherie, 1991). Zircon dating indicates that plutons were episodically emplaced from Late Mississippian to Permian, during post-collisional extension and exhumation of the crust (Casini et al, 2013;Paquette, Ménot, Pin, & Orsini, 2003).…”

Section: Geological Settingmentioning

confidence: 99%

Structural map of Variscan northern Sardinia (Italy)

et al. 2014

View full text Add to dashboard Cite

In this paper, we present a geological structural map (1:100,000 scale, 2300 km 2 surface area) of the Variscan basement of northern Sardinia. The map integrates field structural analysis, extensive gamma-ray spectrometry, and high-resolution ELA-ICP-MS U/Th-Pb zircon and monazite dating. A set of 10 samples of granitic rocks collected from different plutons were characterized for their crystallization age. This provided an accurate timing of magmatic events related to the development of the Corsica-Sardinia Batholith. The structural map, complemented with geochronological results represents a benchmark for future studies on Variscan geodynamics.

show abstract

“…Isotopic data, in particular Nd, point to mantle-crust interactions in the magma sources, with increasing contributions from a depleted mantle (positive εNdi) at the end of the magmatic activity (ca. 280 Ma; Innocent et al 1994;Monjoie et al 2002;Paquette et al 2003;Monjoie 2004). This last magmatic pulse of Early Permian age is tightly connected to large scale transtensional tectonics, accompanied by the formation of volcano-sedimentary basins in the upper crust, and ductile thinning and exhumation of the lower crust (Mulch et al 2002;Schaltegger & Brack 2006).…”

Section: Introductionmentioning

confidence: 99%

“…Magmatic activity occurred as discrete and short-lived pulses (e.g. Schaltegger 1997;Bussy et al 2000;Paquette et al 2003), triggered by mantle upwelling and thermal relaxation of the lithosphere, controlled in space and time by tectonic factors. These dominantly granitic rocks display an evolution through time from high Mg-K calc-alkaline to calc-alkaline and finally alkaline affinity.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Contrasting magma types and timing of intrusion in the Permian layered mafic complex of Mont Collon (Western Alps, Valais, Switzerland): evidence from U/Pb zircon and 40Ar/39Ar amphibole dating

et al. 2007

View full text Add to dashboard Cite

Magma types and timing of intrusion in the Mont Collon gabbro 125 ABSTRACT We have selected and dated three contrasting rock-types representative of the magmatic activity within the Permian layered mafic complex of Mont Collon, Austroalpine Dent Blanche nappe, Western Alps. A pegmatitic gabbro associated to the main cumulus sequence yields a concordant U/Pb zircon age of 284.2 ± 0.6 Ma, whereas a pegmatitic granite dike crosscutting the latter yields a concordant age of 282.9 ± 0.6 Ma. A Fe-Ti-rich ultrabasic lamprophyre, crosscutting all other lithologies of the complex, yields an 40 Ar/ 39 Ar plateau age of 260.2 ± 0.7 Ma on a kaersutite concentrate. All ages are interpreted as magmatic. Sub-contemporaneous felsic dikes within the Mont Collon complex are ascribed to anatectic back-veining from the country-rock, related to the emplacement of the main gabbroic body in the continental crust, which is in accordance with new isotopic data. The lamprophyres have isotopic compositions typical of a depleted mantle, in contrast to those of the cumulate gabbros, close to values of the Bulk Silicate Earth. This indicates either contrasting sources for the two magma pulses -the subcontinental lithospheric mantle for the gabbros and the underlying asthenosphere for the lamprophyres -or a single depleted lithospheric source with variable degrees of crustal contamination of the gabbroic melts during their emplacement in the continental crust. The Mont Collon complex belongs to a series of Early Permian mafic massifs, which emplaced in a short time span about 285-280 Ma ago, in a limited sector of the post-Variscan continental crust now corresponding to the Austroalpine/Southern Alpine domains and Corsica. This magmatic activity was controlled in space and time by crustal-scale transtensional shear zones.

show abstract

Episodic and short-lived granitic pulses in a post-collisional setting: evidence from precise U–Pb zircon dating through a crustal cross-section in Corsica

Cited by 133 publications

References 26 publications

Genesis and emplacement of felsic Variscan plutons within a deep crustal lineation, the Penacova-Régua-Verín fault: An integrated geophysics and geochemical study (NW Iberian Peninsula)

Genesis and emplacement of felsic Variscan plutons within a deep crustal lineation, the Penacova-Régua-Verín fault: An integrated geophysics and geochemical study (NW Iberian Peninsula)

Structural map of Variscan northern Sardinia (Italy)

Contrasting magma types and timing of intrusion in the Permian layered mafic complex of Mont Collon (Western Alps, Valais, Switzerland): evidence from U/Pb zircon and 40Ar/39Ar amphibole dating

Contact Info

Product

Resources

About