Witch Craig Wall EarthCache

The Witch Craig Wall is a stone enclosure which takes its shape from a sheep fold. Built within the enclosure are 43 special igneous, metamorphic and sedimentary rocks which have been collected from locations across the panorama seen from the viewpoint to illustrate the geology of the Central Scotland area.

Central Scotland is often referred to as the Central Lowlands. This area is a rift valley mainly comprising of Paleozoic formations. A rift valley is a linear-shaped lowland between several highlands or mountain ranges created by the action of a geologic rift or fault. This rift valley is known as the Midland Valley which lies between the Highland Boundary Fault to the north and the Southern Uplands Fault to the south.

The Central Scotland area has intense vulcanism as seen in Edinburgh at Arthur’s Seat which was part of a large volcano active 300 million years ago. The Central area is relatively low-lying compared to the Highland region of Scotland.

A rift valley is formed on a divergent plate boundary, a crustal extension, a spreading apart of the surface, which is subsequently further deepened by the forces of erosion. When the tensional forces were strong enough to cause the plate to split apart, a centre block dropped down between the two blocks at its flanks, forming a graben. This drop created the nearly parallel steeply dipping walls of rift valley. This feature was the beginning of the rift valley and as the process continues, the valley widens, until it becomes a large basin that fills with sediment from the rift walls and the surrounding area.

To log the EarthCache, please email the CO with the answers to the following questions:

1. Look at the Ochil Hills in the distance towards the Highland boundary fault. Estimate the distance (in miles or kilometres) from Witch Craig Wall to the Ochil Hills.

2. Estimate the height of the Witch Craig Wall location above the rift basin

3. Sit on a seat facing north-west. Look at the nearest lettered stone to your left. This stone is from Bathgate, one of the nearby towns within the rift valley. Describe the appearance of the rock in terms of texture, colour and formation.

Optional task– Post a photograph of yourself, your team or your GPS with Witch Craig Wall or the view.

You do not have to wait for a reply from the CO but please send your answers by email before logging your find, otherwise your log will be deleted.

Parking: Park at the lay-by as shown by the waypoint (near to the Korean War Memorial) and follow the footpath through the memorial site up the hill.