strati.ch - Lexique lithostratigraphique de la Suisse

Représentation et statut

Variantes historiques: Südlicher Aaregranit (Huber 1948, Niggli et al. 2008, Labhart & Renner 2012), Normaler Aare-Granit bzw. Saurer Granit der zentralen Intrusivzone (Bl. Trun), Strem Granite (Berger et al. 2017), Strem-Granit (Gisler 2018)

Remarques nomenclatoriales: Südlicher Aare-Granit p.p., Southern Aar Granite p.p.

Âge au sommet

Âge à la base

Extension géographique: 20 km lange Intrusion zwischen Gütsch/Oberalppass und Piz Avat/Piz Posta Biala.

Définition: Berger Alfons, Mercolli Ivan, Herwegh Marco, Gnos Edwin (2017) : Geological Map of the Aar Massif, Tavetsch and Gotthard Nappes. Geological Special Map 1:100'000, Explanatory Notes 129

p.39: The Strem Granite is a greyish, porphyric granite showing a well-developed foliation with local transition to an “Augengneis” (HUBER 1948). A brighter equigranular facies (“Randfazies”) dominates the eastern part of the granite. This easternmost part has been described as “Piz Ner Granite” and occurs associated with a group of intrusions that are older than the Central Aar Granite (WEHRLI 1896, EUGSTER 1951). Despite the distinctive petrographic character, it was impossible to trace a limit between the Strem Granite and the Central Aar Granite at its western end (SPILLMANN et al. 2011), where a separation by polycyclic metamorphic basement is missing. The Strem Granite has no connection with the Southwestern Aar Granite, the latter belonging to the Haslital Group. Unfortunately, these two distinct intrusive bodies were always reported together as “Southern Aar Granite” in the literature.