Scaglie Orobiche inferiori

Representation and status

Index

UO

Color CMYK

N/A

Color RGB

R: 241 G: 239 B: 237

Rank

complex of tectonic slices

Validity

Unit is in Use

Status

valid

Nomenclature

Deutsch

Untere Orobische Schuppen

Français

Écailles Orobiques inférieures

Italiano

Scaglie Orobiche inferiori

English

Lower Orobic Imbricates

Origin of the Name

Alpi Orobie = Bergamasker Alpen

Historical Variants

Lower Orobic Imbricates (TK500 / Gouffon et al. 2024)

Hierarchy and sequence

Subordinate units

• Unità della Val Trompia

Units at roof

• Falda Orobica superiore

Units at floor

• Milano Belt

Geography

Geographical extent

Alpi Bergamasche, Giudicarie.

Palaenography and tectonic

Paleogeography

Adriatic continental margin :

southern, passive continental margin / platform

Tectonic unit (resp. main category)

• Lower Orobic

Kind of protolith

• tectonic

References

Definition

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

p.103: The en-échelon arrangement of the ramp anticlines in the Lower Orobic Imbricates is similar to that of the Upper Orobic Nappe with a more diffused deformation in the sedimentary cover. A large part of the Bergamasc Alps and of the Giudicarie region belongs to this unit.

p.109: The Lower Orobic Imbricates, underlying the Upper Orobic Nappe, can be followed from the Lago di Garda, in the east, up to the Lugano Fault in the area of Monte Generoso, in the west. The westernmost part of the Lower Orobic Imbricates is separated from the Upper Orobic Nappe by the Lugano – Monte Grona fault system, a reactivated Mesozoic normal fault separating the Lugano High from the Generoso Basin (see p. 102). During the Alpine orogeny, the pre-existing fault acted mainly as a transcurrent fault: sinistral in the north, east of Lugano, and merging with the northward Monte Grona Backthrust (Bertotti 1991), placing the Lower Orobic Imbricates atop the Upper Orobic Nappe; dextral in the south, near Mendrisio (Bernoull i et al. 2018). South of Mendrisio, the continuation of the Lugano Fault is lost within the tightly folded Late Cretaceous flysch. The Lugano Fault does not affect the Monte Olimpino Backthrust of the Milan Belt, and is therefore older. To the east, the sediments of the former Generoso Basin are separated from the Upper Orobic Nappe of the Bergamasc Alps by the NW–SE trending Lecco Fault, probably a reactivated Mesozoic fault (Bertotti 1991, Schumacher et al. 1997). However, in the southeast, a link with the Lower Orobic Imbricates of the Bergamasc Alps exists (Schumacher et al. 1997).