Unità dei Gneiss minuti

Representation and status

Color CMYK

(0%,0%,0%,100%)

Color RGB

R: 240 G: 200 B: 200

Rank

tectonically bounded lithostratigraphic unit

Validity

Unit is in Use

Status

informal term

Nomenclature

Deutsch

Gneiss-Minuti-Einheit

Français

Unité des Gneiss minuti

Italiano

Unità dei Gneiss minuti

English

Gneiss Minuti Unit

Origin of the Name

= gneiss à grain fin

Historical Variants

Gneiss Minuti (Gastaldi 1871, Gastaldi 1874, Dal Piaz et al. 1972, Compagnoni et al. 1977), Gneiss albitiques (Comes 1975), "Gneiss Minuti" complex (Compagnoni et al. 1977), gneiss minuti (Dal Piaz et al. 1992a), External Sesia-Lanzo zone = gneiss complex (Conticelli et al. 2010)

Description

Description

Externe Einheit der Sesia-Zone, vorwiegend mit grünschieferfaziellen Paragenesen (nur vereinzelten Relikten einer Hochdruckmetamorphose): Metagranodiorite, Metagranitoide, sowie gebänderte Paragneise, Prasinite une Amphibolite.

albite-white mica gneisses and schists ; Métagranitoïdes et granodiorites, associés à des roches rubanées d'origine volcano-sédimentaire probable (Comes 1975)

Hierarchy and sequence

Subordinate units

• Ortogneiss della falda di Sesia

Geography

Geographical extent

Val d'Aoste.

Palaenography and tectonic

Paleogeography

Adriatic continental margin :

southern, passive continental margin / platform

Tectonic unit (resp. main category)

• Sesia

Metamorphism

polycyclic

Metamorphic facies

• greenschist facies (epizone)
• eclogite facies

Note on metamorphism

Im NW der Sesia Zone werden die Hochdruckparagenesen sukzessive von jüngeren

grünschieferfaziellen Paragenesen verdrängt, so daß in den externen Anteilen

("Gneiss Minuti") die Gesteine nur noch in vereinzelten Relikten die Einflüsse einer

Hochdruckmetamorphose belegen (Compagnoni et al. 1977; Richter 1983;

Venturini 1995).

References

Definition

Gastaldi B. (1871) : Studi geologici sulle Alpi Occidentali - Parte I. Memorie del Regio Comitato Geologico Italiano 1, 1-47

Definition

Gouffon Yves (Editor) (2024) : Tectonic Map of Switzerland 1:500000, Explanatory notes. Federal Office of Topography swisstopo, Wabern

p.81: The Gneiss Minuti Unit consists mainly of orthogneisses, derived from granitoid of probable Permian age and interbedded with more mafic layers. High-pressure metamorphism of this unit was largely obliterated by the later greenschist-facies metamorphism.