Norbert
I'm not a geologist either, but I did stay in a Holiday Inn even before they had their "Express" brand and when it cost about $4.50/night for a double room.....
Dornoch is built over three cascading landforms--the uppermost of which contains the 1st and 2nd hole are, as well as the 5th tee, the 7th, the 8th tee, the 16th green, the 17th tee and the 18th. The lowest and most immature of the landforms consists of the (lower) 8th fairway and green, the 9th to the 15th, the 16th tee and the (lower) 17th fairway. The middle and most interesting landform consists of the 3rd fairway, the 4th hole and the 5th fairway. This land slopes down from the hillside of gorse toward the sea, and includes those fingers of land that jut into the right hand side of the fairways of the 12th through 15th holes and also are in play on the outward 9, particlarly to the right of the 3rd and 4th.
I personally have never even considered that their (relative) flatness was anything but natural, as the land from which they flow is also relatively flat (if sloped). I assume that the hollow areas which make the fingers are the result of some sort of erosion. I don't think there is any kind of bedrock there, having played out of all parts of most of those fingers far too many times.
The 14th green is, of course, the most famous of the fingers, and as you will know, it is anything but flat. AS is the 4th green, another of the fingers.
So there!
You know the address for slag delivery, I presume....
Cheerfully
Ricardo