After Nadeshiko returns from the Oigawa trip, the other Outclub girls recount for her (somewhat dubiously) a spontaneous bus-based camping trip they took while she, Rin, and Ayano were away.
They apparently formed when the 
Yatsugatake Mountains erupted.
يبدو أنّها تشكّلَتْ عندما ثارَ بركان ياتسوغاتاكي
Die sind bei Ausbrüchen
des Yatsugatake entstanden.
Los creó la erupción
de la cordillera de Yatsugatake.
Los creó la erupción
de la cordillera Yatsugatake.
Merci les éruptions
des monts Yatsugatake.
Si sono formate in seguito alle eruzioni 
del gruppo vulcanico Yatsugatake.
Parece que foram formados quando os vulcões
da Cordilheira Yatsugatake entraram em erupção.
А они вроде как
при извержении Яцугатакэ сформировались.