The Great Bluestone Hunt

This is the area where, I suspect, real progress is likely to be made in the coming years. The area shown in yellow is the approx area of the "Fishguard Volcanics" on the northern flank of Mynydd Preseli -- here, as I have indicated, there are complex extrusive rocks thrown out during Ordovician volcanic eruptions -- and some intrusives too. Typical rocks are rhyolites, breccias, ignimbrites, tuffs and welded tuffs -- and because some of the eruptions were in the sea, there are layers of detritus and pebble beds that look more like sedimentary rocks than igneous ones. The map is not very accurate -- there are certainly some ashes and other volcanics exposed in the coastal cliffs between Cwm-yr-Eglwys and Newport.

I wouldn't mind betting that some of the igneous fragments from the Stonehenge area will be matched up with rocks from these Fishguard Volcanic Series outcrops. Secrets out there, waiting to be discovered........