Demerits are listed in Schedule 1 of this document:
http://www.canlii.org/en/ab/laws/reg...-331-2002.html
Fines for various offences are listed in this document:
http://www.transportation.alberta.ca...plquickref.pdf
For 21km over the posted limit, you're looking at 3 demerits and a $129 fine.