Nappe des Gets

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Representation and status

Index
Gt
Color CMYK
N/A
Color RGB
R: 241 G: 239 B: 237
Rank
nappe
Validity
Unit is in Use
Status
valid

Nomenclature

Deutsch
Gets-Decke
Français
Nappe des Gets
Italiano
Falda dei Gets
English
Gets Nappe
Origin of the Name

Les Gets (Haute-Savoie, France)

Historical Variants

nappe du Col des Gêts (Trümpy 1976), nappe des Gets (Plancherel 1998), Gets nappe (Bill et al. 2001)

Description

Description

riche en ophiolites (cf. schistes lustrés piémontais ou Canavese ligure)

Hierarchy and sequence

Lower boundary

Les parties internes de la nappe chevauchent la nappe de la Brèche, tandis que les parties externes chevauchent la nappe de la Simme.

Age

Age at top
  • Campanian
Age at base
  • Cenomanian

Geography

Geographical extent
Des Gets (France) à Zweisimmen.
Type area
Massif des Gets (Chablais savoyard, France)

Palaenography and tectonic

Paleogeography
Piemont Basin
Tectonic unit (resp. main category)
Kind of protolith
  • ophiolitic
Metamorphism
monocyclic
Metamorphic facies
  • low-grade metamorphism

References

Definition
Bill Markus, Masson Henri, Thélin Philippe (2001) : Low-grade metamorphism of the Gets nappe (Western Alps). Schweiz. Mineral. Petrogr. Mitt. 81, 229-237

The Gets nappe is a decollement cover nappe situated in the front of the Alpine belt. This nappe was affected by very weak metamorphism, preliminary illite crystallinity data suggest anchizonal conditions (Caron and Weidmann, 1967).

[...]

The Gets nappe is composed of two series (Caron, 1972): the base of the nappe (Perrieres series) essentially comprises a composite wildflysch containing ophiolitic material (serpentinite, gabbro, basalt and diabase). deep marine deposits (radiolarite, pelagic limestone, manganiferous shale), and Palaeozoic granite, all embedded in a shaly matrix (Fig. 2). The disrupted oceanic crust, the melange of ophiolitic rocks and the chaotic sedimentation are characteristic of an accretionary prism sequence (e.g. Mascle et al., 1988; Pickering et al., 1989). Isotopic dating, trace element data and Sm-Nd isotopes of the gabbros and basalts of the Gets nappe, together with structural and stratigraphic evolution of the northwest Shoulder of the Piedmont rift indicate that. at least in part, the ophiolitic material of the Gets nappe is a remnant of the onset of the Piedmont ocean spreading (Bill et al. 1997,2000,2001).The composite wildflysch is overlain by the Hundsrück series, composed mainly of turbiditic sandstones and polygenic conglomerates of Upper Cretaceous age.

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