Looking west from Heoga Neap you can see the line of the Moine Thrust. This is where rocks of the Moine Supergroup were thrust up over the much older rocks of the Lewisian basement as the Caledonian Mountains formed between 480 and 390million years ago. In Shetland it is known as the Wester Keolka Shear. The Moine thrust is the easternmost, and oldest, of a series of low-angle faults. These make up a thrust belt within which older sheets of rock (or nappes) are piled up over younger sequences. Rock sequences have been faulted and disrupted all along the Moine thrust belt. The Moine thrust was first identified on the Scottish Mainland at Knockan Crag. Its discovery in 1907 by Ben Peach and John Horne was a milestone in the history of geology as it was one of the first thrust belts discovered. It was of international significance as it helped geologists to understand the tectonic processes involved in mountain formation.
This viewpoint looks onto the Wester Keolka Shear Zone - a fault along which the Caledonian mountains were thrust over Shetland's basement rocks.
Directions
Heoga Neap is in the North Mainland to the north of North Roe
Take the A970 to North Roe and turn off to Sandvoe
Park opposite the cemetery, then walk to the end of the road and along the track
At the end of the track head north across the burn and up the hill of Heoga Neap