For those who are geologists, or who are just interested in the geology of the Preseli area, here is a newish paper about the Fishguard Volcanics. It's very technical, and it concentrates on the Strumble - Pen Caer exposures, but it's good solid background info!
On the map, the FVG rocks are shown with the grey wash -- the foliated rhyolites at Rhosyfelin belong within this group.
BETHAN A. PHILLIPS, ANDREW C. KERR & RICHARD BEVINS
A re-appraisal of the petrogenesis and tectonic setting of the Ordovician Fishguard Volcanic Group, SW Wales
Geol. Mag.153 (3), 2016, pp. 410–425.
doi: 10.1017/S0016756815000461
https://www.researchgate.net/publication/282801686_A_re-appraisal_of_the_petrogenesis_and_tectonic_setting_of_the_Ordovician_Fishguard_Volcanic_Group_SW_Wales
The link does not work
ReplyDeleteDave
It's probably broken in the middle. Try to eliminate spaces that might have been introduced....
ReplyDelete