3.9 - PORTH CLAIS - ST JUSTINIAN`S
Pre-Cambrian Rocks
Pre-Cambrian Rocks are the oldest in Pembrokeshire - (600 million years old) .
This headland (Picrite) , islets Carreg Fran - Carreg Yr Esgob and the east side of
Porthlysgi Bay are formed from "Granophyre" , a white rock (microgranite) ,
rich in silica , mica , feldspar , that intrudes into the other
Volcanic Rocks that form Treginnis Headland , further to the west.
Dodder plants grow through the Gorse on the heathland above this viewpoint.
Ref: 10767.8
Date: 08/09/2012
Location: SM 730 233
