During the Weichselian late glacial, Borgarfjörður and Melasveit have been covered by glacier in several forms since the last glacial maximum in Iceland.
Á Siðjökulskeiði lá jökull yfir Borgarfirði og Melasveit í nokkrum myndum eftir hámark seinasta jökulskeiðs á Íslandi.