Geology of the southern Gran Paradiso Massif and Lower Piedmont Zone contact area (middle Ala Valley, Western Alps, Italy)
| Autor: | F. Caso, S. Nerone, A. Petroccia, M. Bonasera |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Journal of Maps, Vol 17, Iss 2, Pp 237-246 (2021) |
| Druh dokumentu: | article |
| ISSN: | 1744-5647 17445647 |
| DOI: | 10.1080/17445647.2021.1911869 |
| Popis: | This work presents the structural evolution of a poorly studied key-area in the middle Ala Valley, Western Alps, where two tectono-metamorphic units are exposed. A geological map at the 1:10.000 scale, integrated with meso- and microstructural analysis, has been realised. We investigated the contact area between Gran Paradiso Massif in the footwall and Lower Piedmont Zone in the hanging wall. Both tectono-metamorphic units, with a different paleogeographic affinity, preserve similar polyphasic deformation histories, defined by four deformation phases. The Dp phase, strongly transposing previous structural relicts, is marked by a high-pressure assemblage associated with the Sp foliation. Dp controls the lithological boundary attitude. A mylonitic zone, developed during the Dp, showing kinematic indicators pointing to a top-to-the N-NW sense of shear, is responsible for the juxtaposition of the two units. Dp structural elements are deformed by Dp+1 and Dp+2 subsequent phases. A greenschist-facies overprinting was observed during the Dp+1 phase. |
| Databáze: | Directory of Open Access Journals |
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