Saturday 5th January 2008 Excursion 1: Penlee Quarry - geology, extractive industry and afteruse Leaders: Professor Geoffrey Walton (PGW&A
LLP) Penlee Quarry is located just south of Newlyn. It primarily exposes thick metadolerites of the Upper Devonian Mylor Slate Formation and is within the contact metamorphic aureole of the Land’s End Granite. The foreshore at Penlee Point, further south, is a GCR Site (Igneous Rocks of SW England) and Penlee Quarry is a GCR Site (Mineralogy of SW England). Early veins host a variety of As, Bi, Cu, Fe, Mo, Pb, Sn, Te and Zn minerals. A large later vein is dominantly of quartz and chalcedony. The quarry, which was dormant for a while in the 1990s, is presently under development for future production of armourstone for local coastal protection and breakwater works. It is intended that the site will eventually be developed into a marina, with associated facilities, together with housing. The visit will include an examination of the geology of the foreshore and quarry (possible through the kind permission of MDL Ltd), along with explanations of the geotechnical and other issues associated with the future development. Meeting point: The quarry office, just inside the main gate, at 10.00 (there is ample parking – reverse parking rules apply). Depart approx. 14.00. Lifts will be available from Tregenna Castle Hotel (departure by 0920). All participants require hi-vis vest, hard hat and safety boots – please let us know if you don’t have these.
Excursion 2: Devonian and Quaternary geology of St Ives Bay Leaders: Dr Robin Shail (Camborne School of Mines, University
of Exeter) The Tregenna Castle Hotel provides, on good days, a superb eastwards view across St Ives Bay towards Godrevy Lighthouse. The excursion will provide an overview of the stratigraphy, sedimentology and structure of the superb Devonian and Quaternary sections exposed in the southern and eastern parts of the Bay at Black Cliff, Gwithian and Godrevy (including three GCR Sites). Lunch will be taken at a public house or café. Meeting point: The excursion will depart, and lifts will be available, from the Tregenna Castle Hotel at 0930. The precise itinerary will be weather/tide dependent.
Excursion 3: Land’s End Granite – geology and mining landscape Leaders: Dr Nick LeBoutillier The excursion will provide an overview of the geology, mineralization and mining landscapes of the northern margin of the Land’s End Granite. The first locality will be Cape Cornwall, where pre-granite host rock deformation, contacts with the granite(s), textural variations, vein mineralization and Quaternary sediments are all superbly exposed. The historic workings of Cape Cornwall, St Just United (± Boswedden) mines will be discussed. The excursion will then head back northeastwards towards St Ives, along the scenic B3306 coast road, stopping at Botallack, Levant/Geevor and Carn Galver mines to further investigate geology, mineralization and mining landscapes. Lunch will be taken at a public house or café. Meeting point: The excursion will depart, and lifts will be available,
from the Tregenna Castle Hotel at 0915. The precise itinerary will
be weather/tide dependent. If you have any comments please contact the web editor |
