If the trap dykes were deposited at the close of the Old Red era, we may reasonably expect them to furnish us with some indication of the processes by which the land attained its present configuration.
Around midmorn on Whitsun, June 8th of 1783, in clear and calm weather,a black haze of sand appeared to the north of the mountains nearest the farms of the Siða area.
“Level with the Old Red Sandstone rocks, with the remains of the Coccosteus lying exposed on their surface, “
“But a more interesting question now arose as to the opposite side of the harbour – Will the trap be found traversing the granite?”
“At very low tides it can be traced outwards for about a hundred yards continuously; but it looks more picturesque at about half tide”