Graphitische Einheit (der Camosci-Decke)

Torna a falda dei Camosci

Rappresentazione e statuto

Colore CMYK
(0%,0%,0%,100%)
Rango
Formazione litostratigrafica
Uso
Unità in uso.

Nomenclatura

Deutsch
Graphitische Einheit (der Camosci-Decke)
Français
Unité graphitique (de la nappe des Camosci)
Italiano
Unità grafitica (della falda dei Camosci)
English
Graphitic unit (of the Camosci nappe)
Varianti storiche
black phyllitic schists + calcschists complex (Bianchi et al. 1998), Graphitic unit = Toarcian-Aalenian (Carrupt 2003)

Descrizione

Potenza
Environ 75 m (Carrupt 2003 Fig.2.4)

Gerarchia e successione

Età

Geomorfologia
  • Aaleniano
Età alla base
  • Toarciano
Metodo di datazione
Ennoyement de la plateforme / black shales au Toarcien-Aalénien (Carrupt 2003).

Referenze

Definizione
Carrupt Elisabeth (2003) : New stratigraphic, structural and geochemical data from the Val Formazza - Binntal area (Central Alps). Mémoires de Géologie (Lausanne) 41, 103 p.

p.17: Graphitic unit: is characterized by important lateral variations of facies (Fig.10.2). The clearest succession is found in the western part of the nappe. A black graphitic micaschists (metashale, see microscopic description in paragraph III.4) containing porphyroblasts of garnets, immediately follows the Calcareous unit; the contact is clear-cut. It may contain rare thin levels of a calcareous graphitic micaschist (metamarls). Bianchi et al. (1998) found various heavily recristallized bioclasts in the black micaschist. The eastern part is more complex. A calcareous graphitic micaschist (metamarls, see microscopic description in paragraph III.4) containing porphyroblasts of plagioclase or epidote overlies the Calcareous unit. The contact is gradual: thin levels (3 cm) of calcareous micaschist alternate with the calcitic marble; the latter becomes thinner upsection, whereas the calcareous micaschist thickens. Some graded bedding can be observed, indicating the local polarity (Fig.2.4). Up sequence, thin levels of black micaschist are interbedded within the calcareous micaschist. The lateral transition between the western and the eastern part of the Graphitic unit is made over less than 2 m. A very hard and dark 50 cm-thick rock composed of graphite (50%), carbonate (29%), muscovite (12%), opaque (8%) and some accessory minerals, represents the transitional stage between the calcareous micaschist and the black micaschist.
  • Detritische Einheit (der Camosci-Decke)

    Name Origin

    Camosci

    Rango
    Formazione litostratigrafica
    Statuto
    termine scorretto (informale)
    In breve

    Métagrès quartzitique et argileux (aspect de paragneiss gris), s'enrichissant vers le haut en grains dolomitiques, avant de passer brusquement à un métagèrs dolomitique très pauvre en quartz et en argile.

    Age
    Giurassico Medio
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