Table B2.9.

Extract from land facet table detailing engineering attributes (see Table B2.8 and Fig. B2.11)

Land facetFormSoils and materialsEngineering properties and comments
4 mFoot slope piedmont. Consists of gently sloping surfaces which link an upland to a lowland facetColluvial/taluvial soils of variable thickness overlying a stepped rock surface. The soil profile generally comprises coarser grained gap-graded cobbles, gravels and sands at the upper levels and finer grained materials at the lower levels. However, extensive intermediate levels can contain appreciable quantities of clayey material where the parent rocks are marl.AASHTO (2004) classification group very variable depending on whether the material has been predominantly derived from the stronger limestone beds (generally A-1-b to A-2-4) or the more extensive weaker marls (generally A-4 to A-6).