The beach material is a medium-grained sand with very few shell fragments, being mostly quartz and mica with lithic fragments. There are cobbles of gabbro and serpentine in swathes and in stream beds.
There is a fairly small area of dune on the west side of the eastern beach. The eastern beach is backed by concrete walls that are old WW2 defences but have collapsed in places.
A link to the Kennack Sands page on the 'Let's Talk Cornwall' website will appear here in due course.