The river flows at first across the peat moorland which overlies the coal measures and millstone grit beneath, and this upper section flows through a narrow "V-shaped" valley that rises from from the riverbed to at the rim of the valley.
The river flows at first across the peat moorland which overlies the coal measures and millstone grit beneath, before flowing across the magnesian deposits east of the valley before the River Ure. The upper section of the river flows through a narrow "V-shaped" valley that rises from from the riverbed to at the rim of the valley.