«Unità del Lucomagno»

Darstellung und Status

Farbe CMYK

N/A

Farbe RGB

R: 241 G: 239 B: 237

Rang

Decke

Gebrauch

Element ist in Gebrauch

Status

informeller Begriff

Diskussion des Status

Nomenklatur

Deutsch

«Lucomagno-Einheit»

Français

«Unité du Lukmanier»

Italiano

«Unità del Lucomagno»

English

«Lucomagno Unit»

Herkunft des Namens

Passo del Lucomagno (TI)

Historische Varianten

Lucomagnomassiv (Jenny et al. 1923), Lucomagnodecke (Bosshard 1925), Lucomagno-Decke (Gansser & Dal Vesco 1964), Ricoprimento Lucomagno (Bianconi 1971), Lucomagno-Masse (Büchi & Trümpy 1976), falda del Lucomagno, Lucomagno unit (Böhm et al. 1996), Lucomagno Nappe (Berger et al. 2017)

Beschreibung

Beschreibung

Involucro paragneissico a misto della falda Leventina-Lucomagno (metapelitischer Paragneis, gebänderter Gneis, Augengneis).

Hierarchie und Abfolge

Untergeordnete Einheiten

• zona del (Pizzo) Molare
• Cristallino di Prato-Cornone

Alter

Alter Top

• Mesozoikum

Alter Basis

• Präkambrium

Paläogeografie und Tektonik

Paläogeografie

Europäische Kontinentalplatte

Tektonische Einheit (bzw. Überbegriff)

• Lucomagno

Referenzen

Neubearbeitung

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

p.50: The Leventina-Lucomagno Nappe is the lowest unit of the Ticino Culmination. The lower part of the nappe (“Leventina Unit”) is made up of several orthogneisses forming a deformed Late Variscan magmatic edifice composed of several magmatic pulses. Along the northeastern flank of the Valle Leventina, the Leventina orthogneisses are covered by a thick stack of paragneisses and micaschists (“Lucomagno Unit”). Along this boundary, sparse quartzitic gneisses (“roof quartzites”) were interpreted as being Mesozoic in age by several authors and hence used to discriminate between a “Leventina Nappe” and a “Lucomagno Nappe”. However, these quartz-rich horizons above the orthogneisses form metasomatically altered zones – in places sheared – and cannot be considered as Mesozoic metasediments (Rütti et al. 2005; see Fig. 7). The “Lucomagno Unit” can therefore be regarded as a pre-Alpine sedimentary shell of the Leventina magmatic edifice deformed during the Alpine orogeny. Quartzitic horizons, similar to those mentioned above, also occur where the Simano Nappe directly overlies the Leventina orthogneisses. The northern part of this nappe contact is often characterized by a mylonitic band (Rütti et al. 2005 and ref. therein). To the south, this mylonitic shear zone dissipates within the Leventina orthogneisses in an anastomosing network of shear bands (Fig. 7). There, the upper limit of the Leventina-Lucomagno Nappe is difficult to trace since paragneiss and calcsilicate lenses – traditionally used to trace the tectonic contact – are in fact deformed xenoliths within the Leventina orthogneisses.
Remnants of Triassic rocks crop out around the frontal part of the Leventina-Lucomagno Nappe, although for some of them it is not clear whether they belong to the Leventina-Lucomagno Nappe or to the adjacent units. Permo-Triassic metasediments crop out also within the Leventina-Lucomagno Nappe, likely as pinched synclines (e.g., Molare Syncline; see Fig. 7) or as intranappe slices.