Looking at the index of deaths on ScotlandsPeople, the maiden name of the mother of the George "Brichen" whose death was registered in Ellon in 1881, aged 84, was "Adams".
The index also shows a marriage for George "Brichen" and Margaret "Adam" recorded in Ellon on 15-4-1786. They must have come from different parishes, as there is also a record for George "Brechin" and Margaret "Adam" in Chapel of Garioch, Aberdeenshire, on 4-5-1786. The dates differ depending on what is recorded - the initial intention to marry, the reading of banns, or the marriage itself.