4 - Porth Oer to Porth Towan
Precambrian Gwna Rocks
The Gwna Group are a chaotic collection of sedimentary and igneous rocks some 610 million years old.
Since deposition the group as a whole has been subject to low grade metamorphism
producing rocks of many colours.
Ref: NW 155
Date: 29/09/2021
Location: SH 2058 3473
