The landscape of the Durness area is a stark contrast to the surrounding areas due to a down-faulted, isolated wedge of Cambro-Ordovician Durness Group carbonates, also historically (and often now informally) known as the 'Durness Limestone'. Although the unit outcrops as far south as Skye, the full sequence can only be seen in the Durness area, hence the name of the unit. This thick sequence (c. ) of dolomites with subordinate limestones and chert is softer than the surrounding hills which are formed of more resistant Lewisian Gneiss or Torridonian sandstones, sometimes capped by Cambrian Quartzite. As a result, the local area is generally flatter and more fertile than other areas in the North West Highlands due to the carbonate bedrock and resultant lime-rich soils.