The Quarterly Journal of the Geological Society of London, Volumen 85,Partes 1-3

abundant Andesites Anthracomya aquilina augite Bala band Barton base biotite boulder-clay boulders breccia Bryozoa Bwlch y Groes calcareous Carbonicola Carboniferous Ceiswyn clay Climacograptus Coal Measures Coalfield coarse Colliery Conglomerate Crag Cwmere Group deposits Dinas Mawddwy drift east eastern Enville exposed exposures farther fault fauna felspar folding forms fossils Froswick Geol Geological Survey Gibbet Hill glacial graptolites gravels Gregory Hill Pericline Hirnant Hirnant Beds horizon inches inlier Kafue Kenilworth Kentmere Keuper Keuper Sandstone Lapworth limestone Llanymawddwy lower marl material miles Millstone Grit minerals Monograptus moraine mudstones Nant north-east north-west northern occur outcrop pebbles plagioclase Prof Q. J. G. S. vol quarry quartz quartzite Rhodesia Rhyolites River rocks sand sandy scapolite Seam seen Series shales shows south-east south-west southern southwards specimens strata Surv syncline Terrace thick thin Tile Hill tourmaline Tuffs Upper Valentian valley Wales western yards Zone