Need some help here guys....

.....anyone who has been on top of Dunadd will know that the surface of the rock is covered with deep scarring. I have always assumed this to have been the effect of glaciation (boulders at the bottom of the glacier scratching as they were dragged over the surface)..... however, I was with a group tonight who were not convinced...

...their main objection to this was that not all the scars run in the same direction...
.....indeed a valid point.....however, I did point out that the glaciers retreated and advanced counless times over millenia.....and not always in the same direction

...they were still not convinced!!

Now the've got me wondering!

I've searched through Google and CANMORE to try to get some definitive info on the geology of this specific area but no joy as yet.

Any suggestions, anyone?

Thanks

FTC