Ruthin town geological walk
Most local people and visitors will walk around the attractive small market town of Ruthin without ever having noticed what I am about to describe. We are all so busy these days and haven't time to stop, stare and wonder why.
Our Ruthin & Berwyn U3A geology groups November outing was a geological walk around Ruthin town guided by group members Brian Hubble and Isabel Stewart. So here are some of the geological features that people fail to notice.
We met in the grounds of St. Peters Church in front of the lovely stone Almshouses. The stone is 330 million year old limestone complete with fossils, brachiopods, crinoids & corals. Around the doorways and windows the stone work is different, it's sandstone, 250 million years old. Sandstone is not as hard wearing as limestone but much easier to cut and carve so it's often used as decoration. This sequence can be seen in many of the town's old buildings. This sandstone was laid down in dessert conditions and rarely contains fossils. Limestone was formed on the sea bed and is composed of the skeletons of sea creatures, algae, coral etc. hence the fossils. Silurian slate, 400 million years old was used for the roof tiles. Before the arrival of the railways only local materials were used for building due to lack of transport and cost.
The two pillars outside County Hall are a delight. Large thumbnail fragments of blue felspar twinkle amongst the black Larvikite pillars, an igneous rock probably from a mine in Norway. The enormous sandstone pillars outside the library were mined locally, probably dressed at the quarry site then transported individually by cart & horses. Quite a task.
Marble steps outside the old picture house may have come from Italy. The War Memorial is built of slate, sandstone & grey granite and the large stone, Maen Huail outside the old Barclay's Bank is a limestone erratic transported underneath the moving ice in the last Ice Age, 12,000 years ago and deposited in the town when the ice melted. It could have travelled miles.
In St. Peter's Square the clock tower, Peers Monument is made of limestone and bands of coloured sandstone. Brachiopod fossils are visible in the limestone. The kerb stones are made of limestone & absolutely full of crinoid fossils probably from a quarry near Matlock. A fantastic sight to see. The relatively new built stone walls around B&M and just beyond the Co-op also have surprises. A single green rock, purple stained rocks and others of interest. I bet you don't know what they are. I do.
Isabel
Photos by Lynne Davies
You can find out much more about the geology of the area in this article by Brian Hubble.
A Geological Walk around Ruthin
Back to Geology group page.