Black Rock is a Prominent Sea Stack on the foreshore at southern end of Widemouth Bay.
The stack is composed of a Slump Breccia in the Bude Sandstones - consisting of large balls of
sandstone and contorted thinner sandstone units, set in a siltstone and mudstone.
Slump Breccias consist of Brecciated Beds derived from downslope slumping.
Location: SS 1960 0169