A report on our meeting on 20th November 2017
There’s nothing Augustinians like better than a rummage into our local history. But how far back can we look? Our speaker Roger Osborne took us back millions of years with his exploration of the local geology. His talk was not only educational and informative but also entertaining, humorous, and interactive.
Roger asked us to remember an important fact. The oldest rocks are at the bottom and the youngest rocks are at the top. Apparently we had now completed the first year of a geology degree although at university they would “dress it up a bit”.
In this area the chalk laid down in the Cretaceous period overlies the light grey limestone rocks of the upper Jurassic. Under that we have the infertile hard craggy rocks of the middle Jurassic good for nothing but trees which our distant ancestors felled and now grows heather in abundance. Then we have the softer mudstones, sandstones and iron stones of the lower Jurassic great for dinosaur fossil hunters. Roger showed examples of some of the typical fossils from each geological period.
These four layers tilted and weathered and are now exposed in succession as we travel from Bridlington north to Guisborough. Roger was able to take us along familiar roads in our minds so we could see exactly where the escarpments are that mark the boundaries between geological periods. Roger said this area is a Mecca for geologists particularly as the coastline gives a cross-section of the four geological eras.
Much more recently four ice ages pulverized, pushed and shoved rocks around particularly at the lower elevations and around the coastline leaving a glacial till as the ice receded. The Holderness plain is made up of this material. This also blocked river routes allowing lakes to form which eventually overflowed to form new river routes. This glacial till is being rapidly eroded by the sea as evidenced by the retreating Holderness coastline and the cliff collapses along the north Yorkshire coast.
Roger also explained how the deep sided dales were formed and how springs resulted in lines of villages along the southern edge of the Yorkshire Moors and Wolds. He commented on the long thin parishes leading up onto the moors designed to give even shares of each type land.
The Prior Bro Garry Sunley asked Maureen Bell to give the vote of thanks. Maureen thanked the speaker for telling the story of our geology in such an informative and entertaining way. She particularly liked the audience participation which was a feature of the speaker’s style.