«Intermediärer Flysch»

Rappresentazione e statuto

Colore CMYK

N/A

Colore RGB

R: 125 G: 125 B: 125

Rango

unità litostratigrafia

Uso

Unità in uso.

Status

termine scoretto (abbandonato)

Nomenclatura

Deutsch

«Intermediärer Flysch»

Français

«Flysch intermédiaire»

Italiano

«Flysch intermedio»

English

«Intermediate Flysch»

Origine del nome

Flysch in intermediäre tektonische Stellung zwischen Blattengrat- und Sardona-Decke.

Varianti storiche

Intermediärer Flysch [non: = Latvinaflysch] (Leupold 1943, Rüefli 1959), Blattengrat-Sandstein (Bisig 1957), Intermediärer Flysch (Wegmann 1961), Intermediärer Flysch = Scheubser Flysch = Lavtinaflysch = Blattengratsandstein (Leupold in: Rutsch et al. 1966), Intermediate Flysch = Scheubser Flysch = Lavtina Flysch = Blattengrat Sandstone = South Helvetic Flysch (Lihou 1995)

Descrizione

Potenza

30-50 m (Lihou 1995).

Componenti

• tracce

Chondrites

Età

Geomorfologia

• Priaboniano

Osservazioni sul tetto

... oder jünger

Età alla base

• Priaboniano

Metodo di datazione

P17 (Lihou 1995)

Geografia

Estensione geografica

Fanenstock, Alp Laui, Alp Scheubs, Alp Foo.

Regione-tipo

Weisstannental (SG)

Località-tipo

• Alp Scheubs (SG), Weisstannental
  Caratteristiche del sito
  • typische Fazies
  Coordinate
  • (2741470 / 1203180)
  Nota
  • Leupold 1943, Rüefli 1959, Herb 1962

Referenze

Definizione

Leupold, W. (1942) : Neue Beobachtungen zur Gliederung der Flyschbildungen der Alpen zwischen Reuss und Rhein. Eclogae geol. Helv. 35/2, 247-291

Revisione

Lihou Joanne C. (1995) : A new look at the Blattengrat unit of eastern Switzerland: Early Tertiary foreland basin sediments from the south Helvetic realm Eclogae geol. Helv. 88/1, 91-114

p.106: Intermediate Flysch

Only at the top of the whole Blattengrat unit is the complete Tertiary stratigraphy preserved so as to include the youngest unit, a 30-50 m thick sandstone flysch variously known as the Intermediate, Scheubser or Lavtina Flysch (Leupold 1943, 1966; Rüefli 1959). the Blattengrat Sandstone (Bisig 1957). or more generally referred to as South Helvetic Flysch (Herb 1988). Found only at the top of the uppermost thrust slice at Fanenstock, east of Elm (Bisig 1957), and on Alp Laui (741-2/205-6), Alp Scheubs and Alp Foo (738-9/201) in Weisstannental (Leupold 1943; Rüefli 1959), it forms both a stratigraphie cap and a universal detachment horizon for the Blattengrat Complex, and therefore is rarely preserved. From Bisig's (1957) account of the flysch, it is transitional from the Flecken Marl, the change marked by the appearance of limestone interbeds within the marl, then fine-grained micaceous sandstones, ultimately becoming interbedded micaceous sandstones and siliceous limestones.

The Intermediate Flysch generally consists of thin, interbedded micaceous fine sandstones, sandy limestones and marl. The parallel-laminated medium grey marl contains Chondrites traces. Such traces are not restricted to one facies association, but the flysch was probably deposited in water depths equivalent to the Flecken Marl. Sandstones are up to 20 cm thick, but most are less than 10 cm thick; they commonly exhibit parallel-, ripple-, undulöse- and convolute-lamination, and can be interpreted as distal sandy turbidites. Grits to fine pebbly conglomerates are locally present and consist of mixed immature detritus deposited as traction carpets beneath sandy turbidites. Quartz is the dominant component, with subordinate dolomite, black mudstone, marl, muscovite and chlorite grains. Volcanic clasts (andésites with a trachytic texture) are relatively common in the coarse fraction. Bioclasts of shallow water large foraminifera, such as Discocyclina and Lithothamnium red algae are also found in the coarse fraction, while planktonic foraminifera, particularly globigerinids. are preserved in the fine fraction.