Reconstructing the Variscan Terranes in the Alpine Basement: Facts and Arguments for an Alpidic Orocline

Geosciences

Michel Faure¹  Jacky Ferrière² 

[1] Institut des Sciences de la Terre d’Orléans (ISTO), UMR 7327-CNRS/Université d’Orléans/BRGM, 1A Rue de la Férollerie, CEDEX 2, 45071 Orléans, France;Laboratoire d’Océanologie et de Géosciences (LOG), UMR 8187, Université Lille/CNRS/Université du Littoral Côte d’Opale, 59000 Lille, France;

关键词: Variscan belt;    Alpine basement;    orocline;    Paleozoic ophiolites;    Western Alps;    South Alpine;   

DOI  :  10.3390/geosciences12020065

来源: DOAJ

【 摘 要 】

The existence of pieces of the Variscan belt in the Alpine basement has been acknowledged for a long time but the correlation of these massifs to the litho-tectonic domains established in Western Europa outside the Alpine chain is still disputed. Due to their ubiquitous character, the abundant late Variscan migmatites and granites are useless to reconstruct the Variscan architecture in the Alpine basement. Ophiolitic sutures, high- and low-grade metamorphic units, and foreland basins provide a preliminary reconstruction of the Variscan orogen exposed in the Alpine basement. The longitudinal extension of the Armorican and Saxo-Thuringian microcontinents between Laurussia and Gondwana is proposed independently of the Intra-alpine and Galatian terranes. The litho-tectonic units of the Corsica-Sardinia segment are correlated to the Moldanubian, Armorican and Saxo-Thuringian Domains. In the Alpine Helvetic and Penninic Domains, the Chamrousse ophiolites are ascribed to the Tepla-Le Conquet suture, whereas the Lepontine, and Stubach ophiolites represent the Rheic suture. The south-directed nappe stack of the South Alpine Domain is similar to the Moldanubian French Massif Central. In the Austroalpine nappe stack, the Ritting ophiolites separate Saxo-Thuringia and Armorica continental blocks. Disentangling the Variscan belt in the Alpine basement suggests a concave-to-the-East arcuate structure called here the Variscan Alpidic orocline.

【 授权许可】

Unknown