05/03/2013 Geology of the Yorkshire Coast Dr Liam Herringshaw - [email protected] Sedimentary rock types 1 05/03/2013 Sedimentary grain size Grain size reflects energy: – - Strong currents pick up larger grains – - Proxy for environment (& sea level) Geology of Yorkshire 2 05/03/2013 Coastal geology of North- East Permian England Triassic Permian on the Yorkshire coast Boulby Potash Mine 3 05/03/2013 Salts from the Zechstein Sea Large, arid, northern European basin Drilling for salts Permian polyhalites 4 05/03/2013 Magnesian Limestone Permian at the coast Caythorpe gas field, near Bridlington 5 05/03/2013 Geology of the Yorkshire Coast - The Cleveland Basin 6 05/03/2013 The Early Jurassic: Redcar – Ravenscar Redcar Mudstone Formation Staithes Sandstone Formation Cleveland Ironstone Formation Whitby Mudstone Formation Lias Group Lias = Old term for lower Jurassic; In Yorkshire (after Powell 1984): - Lower Lias = Redcar Mudstone Formation; - Middle Lias = Staithes Sandstone Formation, Cleveland Ironstone Formation; - Upper Lias = Whitby Mudstone Formation 7 05/03/2013 Lias of Yorkshire Redcar Mudstone Formation Robin Hood's Bay Redcar Earliest Jurassic unit on Yorkshire Coast – - Divided into 4 members 8 05/03/2013 Redcar Rocks Redcar Rocks geological map (Rawson & Wright 1992) 9 05/03/2013 Hummersea Image © Dave Eagle, geograph.org.uk Common fossils Gryphaea arcuata, an Early Jurassic 'oyster' 10 05/03/2013 Trace fossils Rhizocorallium, Boggle Hole Robin Hood's Bay 11 05/03/2013 Robin Hood's Bay Why does Redcar Mudstone Fm reappear so far south of Redcar? The Peak Fault 12 05/03/2013 The Cleveland Anticline Older rocks reach surface in axis of fold Links North Yorkshire Geodiversity Partnership: http://www.nygp.org.uk/index.php North-East Yorkshire Geology Trust: http://www.avm-branding.com/neygt/pages/whatwedo.html Tees Valley RIGS Group: http://www.tvrigs.org.uk/ 13 05/03/2013 Links Boulby Potash Mine http://www.mining-technology.com/projects/boulby/ North Yorks geology (Natural England): http://www.naturalengland.org.uk/ourwork/conservation/geodiversity/englands/counties/area_ID41.aspx Durham & Tees geology (Natural England): http://www.naturalengland.org.uk/ourwork/conservation/geodiversity/englands/counties/area_ID11.aspx Links British Lower Jurassic Stratigraphy: http://www.thegcr.org.uk/ImageBank.cfm?v=30&Style=All RMF, Redcar Rocks: http://www.redcar.ukfossils.co.uk/ RMF, Hummersea: http://www.tvrigs.org.uk/archives/69 RMF, Robin Hood's Bay: jncc.defra.gov.uk/pdf/gcrdb/GCRsiteaccount1943.pdf 14 .