Crust‐mantle relationships in the French Variscan chain: the example of the Southern Monts du Lyonnais unit (eastern French Massif Central)

Gardien, Véronique; Tegyey, M.; Lardeaux, J. M.; Misseri, M.; Dufour, Éric

doi:10.1111/j.1525-1314.1990.tb00481.x

Cited by 53 publications

(30 citation statements)

References 61 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5), where continental pieces of an archipelago-like ribbon-continent followed a dextral strike-slip system during contemporaneous oblique subduction. Also, the Devonian evolution in Belledonne and in the Brevenne-Lyonnais basin [30,31], interpreted as a Devonian rift in an attenuated continental crust [50], is a time-parallel evolution which may coincide with the opening of the Palaeotethys. A further parallel may exist in the chaotic assemblages of serpentinites, granulites, metaperidotites, and eclogites, hosted in former metapelitic metasediments of the Aiguilles-Rouges [76,79], which could correspond to certain ''leptynite-amphibolite complexes'' of the upper gneiss nappe of the French Central Massif and the Maures massif (see above).…”

Section: Variscan Plate-tectonic Evolutionmentioning

confidence: 99%

The Variscan evolution in the External massifs of the Alps and place in their Variscan framework

Raumer

Bussy

Stampfli

2009

Comptes Rendus. Géoscience

View full text Add to dashboard Cite

In the general discussion on the Variscan evolution of central Europe the pre-Mesozoic basement of the Alps is, in many cases, only included with hesitation. Relatively well-preserved from Alpine metamorphism, the Alpine External massifs can serve as an excellent example of evolution of the Variscan basement, including the earliest Gondwana-derived microcontinents with Cadomian relics. Testifying to the evolution at the Gondwana margin, at least since the Cambrian, such pieces took part in the birth of the Rheic Ocean. After the separation of Avalonia, the remaining Gondwana border was continuously transformed through crustal extension with contemporaneous separation of continental blocks composing future Pangea, but the opening of Palaeotethys had only a reduced significance since the Devonian. The Variscan evolution in the External domain is characterised by an early HP-evolution with subsequent granulitic decompression melts. During Visean crustal shortening, the areas of future formation of migmatites and intrusion of monzodioritic magmas in a general strike-slip regime, were probably in a lower plate situation, whereas the so called monometamorphic areas may have been in an upper plate position of the nappe pile. During the Latest Carboniferous, the emplacement of the youngest granites was associated with the strike-slip faulting and crustal extension at lower crustal levels, whereas, at the surface, detrital sediments accumulated in intramontaneous transtensional basins on a strongly eroded surface. RésuméÉvolution varisque dans les massifs externes des Alpes et place dans leur cadre varisque. Dans la discussion générale sur l'évolution Varisque en Europe centrale, le socle pré-Mésozoique des Alpes est souvent inclus avec hésitation. Relativement bien préservés du métamorphisme alpin, les massifs externes des Alpes représentent pourtant un exemple excellent d'évolution du socle Varisque, incluant des microcontinents dérivés de Gondwana avec leurs reliques d'une évolution cadomienne. Les massifs externes témoignent, depuis le Cambrien au moins, de la genèse de l'océan Rhéique. Après la séparation d'Avalonia, la bordure de Gondwana a été soumise à une extension crustale accompagnée de la séparation de microcontinents. L'ouverture de la Paléotéthys, depuis le Dévonien, a eu peu d'influence sur ces massifs. L'évolution Varisque des massifs externes témoigne d'une évolution HP précoce, suivie d'une fusion de décompression sous conditions granulitiques. Pendant le raccourcissement * Corresponding author.E-mail address: Juergen.vonRaumer@unifr.ch (J.F. von Raumer).

show abstract

Section: Variscan Plate-tectonic Evolutionmentioning

confidence: 99%

The Variscan evolution in the External massifs of the Alps and place in their Variscan framework

Raumer

Bussy

Stampfli

2009

Comptes Rendus. Géoscience

View full text Add to dashboard Cite

show abstract

“…7), whereas the third generation of structures, associated to nappe stacking, formed under lower pressure conditions (D, Fig. 7; LARDEAUX & DUFOUR, 1987;LAR-DEAUX, 1989;GARDIEN et al, 1988) at 350-340 Ma (CosTA et al, 1989.…”

Section: ~mentioning

confidence: 94%

Comparison of PTt paths in allochthonous high pressure metamorphic terrains from the Scandinavian Caledonides and the French Massif Central: Contrasted thermal structures during uplift

1991

Self Cite

View full text Add to dashboard Cite

“…The Gföhl Unit and its correlatives in the Kutná HoraSvratka Terrane, however, are unique in containing garnet peridotite in addition to spinel peridotite. Elsewhere in the European Variscides, garnet peridotite also occurs in the Saxothuringian Zone of the Bohemian Massif (Schmädicke and Evans 1997) and in Moldanubian tectonic units in other Variscan massifs, including the Schwarzwald (Kalt et al 1995;Kalt and Altherr 1996), Vosges , and Massif Central (Lasnier 1971;Gardien et al 1990). …”

Section: Peridotites In the Moldanubian Zonementioning

confidence: 99%

The Sklené garnet peridotite: petrology, geochemistry, and structure of a mantle-derived boudin in Moldanubian granulite

Medaris¹,

Ackerman²,

Jelínek³

et al. 2012

J. Geosci.

View full text Add to dashboard Cite

The Moldanubian Sklené garnet peridotite, which preserves mineralogical, geochemical, and structural evidence for a protracted mantle evolution, is a small boudin (~1 m) enclosed by granulite of the Gföhl Assemblage. The peridotite has a porphyroclastic texture, in which large garnet and smaller olivine and pyroxene porphyroclasts (Stage 1) reside in a fine-grained, recrystallized matrix of olivine, pyroxene, and pargasitic amphibole (Stage 2). Garnet is surrounded by kelyphite, consisting of an outer zone of pargasite and an inner zone of spinel and pyroxene (Stage 3). By comparison with other Moldanubian garnet peridotites in the Czech Republic, the Sklené peridotite likely represents a fragment of subcontinental lithospheric mantle. It experienced early partial fusion and depletion of incompatible elements at moderate pressure in the spinel stability field, followed by transport to high-pressure conditions at 1230 ºC and 50 kbar, where the Stage 1 garnet-bearing assemblage was stabilized. Subsequently, the depleted peridotite was metasomatized by transient, primitive basaltic melts, with the addition of Rb, Th, U, Pb, and Sr. Dynamic recrystallization, possibly with a progressive transition to grain size sensitive creep, occurred during Stage 2 at ~915 ºC and 24 kbar in a flattening-dominated, transpressive deformation regime. This event occurred prior to incorporation of the peridotite in granulite and may reflect the early stages of convergence between Brunia and Moldanubia. The static recrystallization and local growth of spinel within kelyphite at 900 ºC and 17-21 kbar (Stage 3) probably took place after entrainment in granulite and was likely isofacial with granulite peak metamorphism.

show abstract

Crust‐mantle relationships in the French Variscan chain: the example of the Southern Monts du Lyonnais unit (eastern French Massif Central)

Cited by 53 publications

References 61 publications

The Variscan evolution in the External massifs of the Alps and place in their Variscan framework

The Variscan evolution in the External massifs of the Alps and place in their Variscan framework

Comparison of PTt paths in allochthonous high pressure metamorphic terrains from the Scandinavian Caledonides and the French Massif Central: Contrasted thermal structures during uplift

The Sklené garnet peridotite: petrology, geochemistry, and structure of a mantle-derived boudin in Moldanubian granulite

Contact Info

Product

Resources

About