The Garleton Hills create an obvious ridge, from the top of the ridge there are wide views over the lower lying areas of East Lothian. The hills are made up of layers of igneous rocks from the Carboniferous which show differing resistance to erosion. In some places the volcanic rocks are both overlaid and underlaid with sandstones. In the volcanic sequence of the hills there is hard basalt lying over trachytic lavas. Glacial erosion has varied according to the variations in the resistance of the rocks. The trachytes slope to the south south east and have been moulded into cuestas, or volcanic trap steps, by the ice. There is a steep north facing scarp with a short dip slope lying to the south of the scarp. The flow of ice and meltwater along the strike of the ridge has eroded furrows and channels. Around the village of Athelstaneford there is a rock basin which has been partly gouged out of the softer basalts.