Port Askaig Tillite Formation

The Port Askaig Tillite Formation (PATF) (also known as the Port Askaig Formation) is a sequence of glacigenic sedimentary rocks deposited during the Cryogenian period of the Neoproterozoic era, forming part of the Dalradian Supergroup. It is exposed along the Dalradian outcrop from Galway, Mayo and Donegal in Ireland in the west through Islay and the Garvellachs in the Inner Hebrides to Schiehallion, Braemar and Fordyce to the east on mainland Scotland.

Source: Wikipedia — Port Askaig Tillite Formation (CC BY-SA 4.0)