Hi there,
Meltorfa is probably of family "Rofabörð" [soil patch(es)] also
referred to as RofBakkar [where the wall formation is dominant).
Here are some links to picturs:
Meltorfa or Rofbakki or Rofabarð.
www.islandia.is/hamfarir/vedur/uppblastur.html
Rofabarð á Arnarvatnsheiði.
www.mountainfriends.com/html/sum04a.html
www.simnet.is/kirkjuboli/Vetrarmyndir/120-2061_IMG_JPG.html
www.rala.is/kvasir/adferdir/Rofgerd/Rofabord.htm
See also "Denudation" under Geology
Thanks Uoden