socle polycyclique anté-varisque du massif des Aiguilles Rouges

Representation and status

Color CMYK

(0%,16%,16%,2%)

Color RGB

R: 250 G: 210 B: 210

Rank

lithostratigraphic Group

Validity

Unit is in Use

Status

informal term

Nomenclature

Deutsch

Prävariszisches polyzyklisches Grundgebirge des Aiguilles-Rouges-Massivs

Français

socle polycyclique anté-varisque du massif des Aiguilles Rouges

Italiano

basamento policiclico ante-varisco del massiccio delle Aiguilles Rouges

English

Pre-variscan polycyclic basement of the Aiguilles Rouges massif

Historical Variants

socle cristallin ancien, Altkristallin des Aiguilles-Rouges-Massivs (Labhart & Rybach 1972), schistes cristallins (Pairis et al. 1992)

Description

Description

Detrital sequences (sandstones and graywackes, with minor carbonate intercalations and tholeiitic basaltic layers) of supposedly Late Precambrian to Ordovician age intruded by S-type and I-type calc-alkaline non-eclogitized metagranites (“Ordovician granitoids”) (Bussy & Von Raumer 1994).

Hierarchy and sequence

Subordinate units

• Gneiss oeillé du Luisin
• Gneiss oeillés du Lac Cornu
• Éclogite du Lac Cornu
• «Grüngesteinskomplex»
• Complexe gneissique d'Emosson
• Complexe gneissique des Chéserys

Units at roof

• roches sédimentaires et volcaniques éovarisques du massif des Aiguilles Rouges

Age

Age at top

• Early Paleozoic

Note about top

Ordovicien ?

Age at base

• L. Proteroz. >>> Neoproterozoic

Note about base

Cambrien ?

Palaenography and tectonic

• Pre-Variscan polycyclic basement of the Helvetic

Tectonic unit (resp. main category)

• Aiguilles Rouges :
  massif des Aiguilles Rouges

Kind of protolith

• sedimentary
• volcanic
• plutonic

Metamorphism

polycyclic

Metamorphic facies

• greenschist facies (epizone)
• amphibolite facies
• mylonitisation
• migmatitisation
• eclogite facies

Note on metamorphism

High amphibolite facies grade and locally anatectic conditions of late Variscan age (327-317 Ma ; Bussy et al., 2000).