Mold town geological walk
On Friday 24th May 20 members of the U3A Geology Group met outside the old Co-Op site in Mold's New Street car park at 1.30 pm for a prompt 2pm start of a geological town walk guided by Professor Cynthia Burek. Our fee of £3 each was donated to Cynthia for RIGS. (Regionally Important /Geomorphological Sites)
Cynthia handed out leaflets covering our walk and explained what we would see. We set off once I had reminded everyone about H&S.
We saw a patio outside a chartered accountants building made up of ovoid, Triassic, quartz pebbles. These were about 250 million years old and had been formed in rivers wider & deeper that any we see today probably acquired from pebble beds in the Stoke area. Cynthia pointed out the slate roofs no doubt from the local slate mines.
I was disappointed that the igneous rock larvikite at the base of a charity shop had been painted over. An eye catching rock with sparkling large crystals. Mined only in S. Norway & Thunder Bay in Canada. Luckily there was a small plaque of this rock in St. Mary's churchyard. (The pillars outside Ruthin Town Hall are made of this same rock.)
We saw sandstone buildings, a bank with limestone blocks full of fragmented shells and a marble plaque. (Marble is the result of pressure & heat on limestone, a metaphoric rock.) The War Memorial was granite, Bethesda sandstone Chapel has two plaques, one marble & slate, the other marble & basalt.
St. Mary's sandstone Church like its sandstone headstones showed the effects of erosion on the soft sandstone.
Llys-yr-Efail (Blacksmith's Court) has a plaque made of igneous rock with very small crystals, this meant it had cooled very quickly. Large crystals are formed when the cooling is a slow process.
Cynthia is an excellent guide and everyone enjoyed our informative afternoon. We hope to see Cynthia again next year.
Isabel
Click to view some Mold walk photos from Mike
Back to Geology group page.