Nair-Porphyroid

Rappresentazione e statuto

Colore CMYK

(0%,51%,64%,24%)

Colore RGB

R: 195 G: 95 B: 70

Rango

Formazione litostratigrafica

Uso

Unità in uso.

Status

termine informale

Discussione del statuto

Nomenclatura

Deutsch

Nair-Porphyroid

Français

Porphyroïde du Piz Nair

Italiano

Porfiroido del Piz Nair

English

Nair Porphyroid

Origine del nome

Piz Nair = Piz Neir (GR) im Juliergebiet

Varianti storiche

Nairporphyr (Cornelius 1912), Nairporphyroid (Cornelius 1932, Cornelius 1935), Quarzporphyr vom Typus Piz Prascheng [Piz Barscheinz] = Nairporphyr (Staub 1946), Nair-Porphyr = Nair-Porphyroid (Rutsch et al. 1966), Volcanics of the LAA = Nair Porphyroid (Furrer et al. 1985), Neir-Porphyroid (Manatschal & Nievergelt 1997), Neirporphyr / Neirvulkanite

Descrizione

Potenza

z.T. mehrere hundert Meter

Gerarchia e successione

Unità di rango superiore

• Vulkanite des Karbons

Unità di rango inferiore

• Lavatèra-Brekzie
• «Pyritquarzit»

Età

Geomorfologia

• Carbonifero

Età alla base

• Carbonifero

Geografia

Estensione geografica

Carungas, Grevasalvas, Bardella, Nair (Err-Decke).

Regione-tipo

Julierpassgebiet (GR) (Err-Decke)

Paleogeografia e tettonica

Condizioni di formazione

Bimodal kalk-alkalischer Vulkanismus (Rhyodazit und Quarz-Andesite).

Metamorfismo

monociclico

Facies metamorfica

• facies a scisti verdi

Referenze

Definizione

Cornelius H. P. (1912) : Petrographische Untersuchungen in den Bergen zwischen Septimer- und Julierpass. N. Jb. Min., etc. 35, 374-

Revisione

Furrer Heinz (Ed.) (1985) : Field workshop on Triassic and Jurassic sediments in the Eastern Alps of Switzerland. Mitt. geol. Inst. ETH und Univ. Zürich (N.F.) 248, 81 S.

p.16: In the LAA similar volcanics and volcanoclastics occur [as in the Ruina Fm.]. The Nair Porphyroid of the Err nappe (Cornelius 1812, 1935) in the Julier pass area consists of a series of metavolcanics (lower greenschist facies) with rhyolitic to dacitic chemistry. (Presence of Quarz-Andesite indicates a bimodal volcanism of the Calc-alcaline group). In the Bernina pass area massive Alkalifeldspar-rhyolites are found. These posthercynian volcanics may be considered as equivalents of the Ruina Fm. in the CAA.