Scope and Content

Comprising details of visit from Criccieth to Portmadoc by C.Burton-Brown, which included Borth-y-Gest, with descriptions of glacial boulder clay and other features, details of exploration of caves, description of views, including a section drawing copied from a journal paper (pages 3-17); details of excursion by BC Nicholson, to examine inland exposures of Ffestinog, Dolgellery and Tremadoc beds, and Dolerite sills in the neighbourhood of Moel-y-Gest, West of Portmadoc. Also including details of visit to Tuhunt-in-Bwlch quarry, a disused fossil locality, where a specimen of Angelina was found, the ascent of Moel-y-Gest to see dolorite, Llanerch Fault at Llanerch Farm, an old slate quarry at Bron-y-foel bach, Cefn-Cyfarwydd a Dictyonema locality, and GW Railway’s quarry at Coed-y-Chwarel (pages 19-31); details of excursion to Aberdaron via Llanystumdwy by C.H Nott, stopping at Penmaen Quarry and Nanhoron including a section diagram of quarry A nearby, and section diagram of the valley of Nant Garw, disused quarry in Bryncroes which Alfred Harker had previously visited, Bwlch y Rhiw, and Nant Gadwen where the club passed a disused Manganese Mine (pages 33-43); details of excursion to St Tudwalls Peninsula via Pwllheli and Llanbedrog by GHS Bushwell, including details of visit to Abersoch for tea and a visit to a quarry at Hend-y-capel where pisolitic iron ores were observed, and details of visits to Trwyn-y-Mulfran, Twyn Llech-y-doll, and Porth Caered including a plan of Hell’s Mouth showing glacial deposits, a section of the east end of Hell’s Mouth and coast section along Porth Caered (pages 45-57); details of excursion to examine the Pre Cambrian of the Lleyn Peninsula by H. Mosley, including visits to quarries where exposures of Sarn Granite and Gneiss were viewed, as well as dolerite further down the stream valley and Penmynyddmica schists; descriptions of how chlorite is produced, and presence of scarlet jaspers, Arenig sandstones at Porth Mendwy, section drawing at Parwyd and section at Porth Mendwy, taken from Matley’s papers (pages 59-71); details of excursion to Afon Dwyfour by CH Baines, viewing silurian sections below Dynana Farm and the study of graptolites, to Plashen wood where exposure of fossiliferous Snowdonian ashes were examined including fragments of fossils (pages 73-79); details of excursion to Carreg-y-defaid and areas around Llanbedrig by Sheila Stevenson, examining exposures and faults, and Tan-y-Mynydd hill and quarry (pages 81-89); details of excursion to Portmadoc to obtain information about the Penmorfa thrust, by Kathleen Winterton, including details of visits to a hill which was once an island in the sea, known at Ynys Cerrig-duon, where exposures of the andesites of the Snowdonian volcanic series were viewed, Ynys Calch where graptolites were found, Pensyflog quarry including a plan of the area around the location showing positions of rocks and shales, Tremadoc iron quarry, Penmorfa slab quarry and metamorphism, Craig-y-Gesail and Graig-y-Castell including sketch map depicting slates, dolerite and bedded ashes and the route taken by club members, and a list of fossils in ‘Professor Fearnsides pit’ (pages 89-105); details of excursion to Penrhyndeudraeth by Leslie Grenfell, including the new explosive works which had quarried the Ffestinog beds where fragments of trilobites were found, the vale of Maentwrog, Harlech and Rhinog grits, and manganese mine; (pages 105-113); and details of final days excursion by RS Barron to the slate quarries at Blanau Ffestinog by toy railway from Portmadoc, with an overview of their geological structure and the general method of working to mine the slate (page 114-121). Many of the entries in this expedition diary mention the Tremadoc beds.

Administrative / Biographical History

The headquarters of the club were at 'Caewylan Private Hotel'. The purpose of the excursion was to study the development of the lower Palaeozoic of the clay and Harlech areas, the Pre-Cambrian of the Aberdawn district and the glacial topography. Participants: Tresillian Charles Nicholas; F. Coles Phillips; W.N Edwards; Raymond Edward Priestley; S.E Hollingsworth; T.A Potts; C.Binton-Brown; Miss Helen Moody; Maurice Black; Miss Sheila Stevenson; Miss Gwendolen Coit; Miss Gertrude Elles; Miss Kathleen Winterton; W.Balfour Gowday; C.J.M Baines; Lesley Cadman; R.L Barron; Albert George Brighton; Miss Alice Walker; D.Gibby; Cecil Edgar Tilley; H Dighton Thomas; B.Clive Nicholson; G.H.S Bushnell; C.R Harvey Nott; B.B Cassy; D.W Whitehouse; Leslie Grenfell.

  • Tuesday April 1st: Criccieth to Portmadoc.
  • Wednesday April 2nd: Ffestinog, Dolgellery, and Moel-y-Gest, West of Portmadoc.
  • Thursday April 3rd: Aberdaron via Llanystumdwy.
  • Friday April 4th: St Tudwalls Peninsula.
  • Saturday April 5th: Lleyn Peninsula, via Llamptundwy.
  • Monday April 7th: Afon Dwyfour Valley.
  • Tuesday April 8th: Carreg-y-defaid.
  • Wednesday April 9th: Portmadoc.
  • Thursday April 10th: Portmadoc and Minffordd.
  • Friday April 11th: Slate quarries at Blaenau Ffestinog.

Geographical Names