Fieldwork, integrated with several techniques for microstructural and geochronological analyses, plays a fundamental part in the study of shear zones. In this guide, we describe a two-day field trip in the Argentera External Crystalline Massif (Western Alps). The Massif is cross-cut by the NW-SE oriented Ferriere- Mollières Shear Zone, a spectacular example of a nearly 25-km-long regional transpressive zone with a maximum thickness of 2 km and a complex and long-lasting evolution during theVariscan time. Recent detailed geological mapping coupled with structural, microstructural, and petrochronological studies reveal that the Ferriere- Mollières Shear Zone was characterized by strain softening that localized strain in its central part during the syn-shearing exhumation and retro-metamorphism. The aim of the field trip is to visit some key outcrops that allow to recognize such evolution and to observe the main features of the Ferriere-Mollières Shear Zone that can be regarded as a good example of a strain softening shear zone in the continental crust.

Strain Softening in a Continental Shear Zone: A Field Guide to the Excursion in the Ferriere-Mollières Shear Zone (Argentera Massif,Western Alps, Italy)

Matteo Simonetti
;
Rodolfo Carosi;Chiara Montomoli
2021-01-01

Abstract

Fieldwork, integrated with several techniques for microstructural and geochronological analyses, plays a fundamental part in the study of shear zones. In this guide, we describe a two-day field trip in the Argentera External Crystalline Massif (Western Alps). The Massif is cross-cut by the NW-SE oriented Ferriere- Mollières Shear Zone, a spectacular example of a nearly 25-km-long regional transpressive zone with a maximum thickness of 2 km and a complex and long-lasting evolution during theVariscan time. Recent detailed geological mapping coupled with structural, microstructural, and petrochronological studies reveal that the Ferriere- Mollières Shear Zone was characterized by strain softening that localized strain in its central part during the syn-shearing exhumation and retro-metamorphism. The aim of the field trip is to visit some key outcrops that allow to recognize such evolution and to observe the main features of the Ferriere-Mollières Shear Zone that can be regarded as a good example of a strain softening shear zone in the continental crust.
2021
Structural Geology and Tectonics Field Guidebook— Volume 1
Springer
Springer Geology Field Guides
19
48
978-3-030-60143-0
Geological filed trip Structural Geology, Alps, Argentera Massif, shear zone, transpression, mylonites, geoligcla maps
Matteo Simonetti; Rodolfo Carosi; Chiara Montomoli
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/1789277
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