Cefn Mawr quarry
On July 26th we met up with Jason Parry the Cefn Mawr Quarry Manager for a guided tour around the busy working quarry. Jason began by explaining the workings of the quarry. How all workers carry a ' walkie talkie ' and know exactly what is taking place from minute to minute, lorries approaching, blasting etc. Health & Safety rules applied at all times and everything is monitored.
Once kitted in Viz jackets, hard hats & goggles we began our tour passing 4 enormous silos that are filled twice daily with limestone aggregate and saw equally large wagons taking their loads away. After a climb of many steps we were level with the top of the quarry and could see the whole of the action. We were even allowed to watch some blasting (see below) which was a bonus. Jason spoke about the different types of limestone the quarry produces and their uses.
Conservation of the site is of paramount importance and the top few layers of the quarry no longer mined are now covered in grass and trees where appropriate. On the way to an area of SSSI (Special Site of Scientific Interest) we passed a limestone cliff face full of brachiopod and crinoid fossils and we could see the layers of mudstone. There are even layers of volcanic ash in some areas of the quarry.
Moving on we came to Jason's SSSI site. A meadow. A project of Jason's. No machinery allowed on this site. Special meadow plants only, attracting butterflies, bees etc. An on going project. Sheep are allowed into this precious area once all the plants have set seed and they eat the grass. It is a splendid site.
This tour was amazing and and the group thought one of our best trips and Jason was an excellent guide. Remarkably the whole event was free. Groups can arrange a visit and I can assure you you won't be disappointed.
Limestone, formed 350 million years ago in warm, tropical seas. Wales at that time was by the equator. Plate tectonics have gradually moved us to where we are now but we are still moving. It can be made up from the body skeletons of algae, shellfish and sponges etc lying on the ocean floor building up in depth over the millions of years.
My favourite rock.
Isabel
Back to Geology group page.
Blasting