’s San Andreas Fault

The Sticklepath Fault runs through the village of Sticklepath, starting on the north coast near down to Torquay in the south.

The Sticklepath fault in Torquay

The geology of Devon is complicated with several episodes of earth movements in the past when earthquakes and volcanoes occurred due to collisions and the splitting apart of continents. This resulted in the formation of the granite of and the many metal deposits found locally. The Sticklepath fault is also responsible for the local ball clay deposits.

The fault, like the San Andreas, moves horizontally and is called a ‘strike/slip’ fault. It has had a complicated history which can be seen by the displacement of the rocks shown in the diagram below. The granite, the black Carboniferous area and the Permian rocks show the fault has moved sinistrally (to the left) after the Permian rocks were laid down, as the rocks can be seen to be off-set. Part of the movement was due to the collision of two continents and later when the continent split apart resulting in the formation of the Atlantic Ocean.

Speckled central mass – granite areas with triangles - Permian Black and white areas – Carboniferous Sloping lines - Devonian rocks from younger to older Dash line – Sticklepath fault

During the Tertiary Period the fault was pulled apart in two places, and Bovey, which created basins. The weathering of the surrounding rocks, importantly the granite, resulted in these basins being filled with sediment which became clay. This is the reason there are important clay quarries along the fault especially around Teignbridge and Newton Abbot.

The Sticklepath fault shows a total displacement of up to 10 km. It is still active and is thought to be responsible for the earth tremors that were felt throughout the region in November 1955.