Many buildings and structures in Much Wenlock have utilised the local stone, giving the town a distinctive look. The town is not as uniformly stone-built as Cotswold towns, but instead uses a rather rough, pale grey stone called Wenlock Limestone, which is quarried from the nearby ridge known as Wenlock Edge.
The clock tower in the Square in Much Wenlock was erected by Mayor Thomas Cooke to commemorate Queen Victoria's Diamond Jubilee in 1897. It is constructed of three different stone types - limestone, sandstone and granite. You need to examine the stones to complete the tasks for this Earthcache.
Limestone
The bulk of the structure is the local Wenlock Limestone, cut into regular blocks with a rusticated finish. Many blocks contain fossil coral as well as crinoids. Crinoids were 'sea lilies', but they were not, as the name suggests, a plant, but animals related to sea urchins and starfish. The information we can get from the fossils in the rock help us to build up a picture of the environment in which the Wenlock Reef formed 20 million years ago. Tropical reefs developed in warm, shallow seas during the Silurian Period, 440 - 410 million years ago. The fossilised remains of one of these reefs are preserved in the rocks known as the Wenlock Limestone.
Sandstone
Panels with wording and shaped surrounds are carved out of single blocks of a different rock. This is Grinshill White sandstone, quarried in the north of the county. This is a sandstone made of wind-blown desert quartz sand, formed in the Triassic Period, 250-208 million years ago. The rounded sand grains are held together by a quartz cement. Grinshill stone has a national reputation as a high quality building material and was used for high-status buildings, not only in Shropshire but throughout the country. The lintel and door surrounds of 10 Downing Street are built of Grinshill Stone.
Granite
The fountain basin is carved out of pink granite. Granite is formed from the slow cooling of red hot molten rock (magma) below the Earth's surface. The interlocking crystals can be carved and polished to give a smooth, hygienic finish. The crystals in granite are large enought to be visible to the unaided eye. Granite is composed mainly of quartz and feldspar. This mineral composition usually gives granite a red, pink, grey or white colour with dark mineral crystals visible throughout the rock. This granite is composed of pink, black and pale grey crystals. The pink crystals are orthoclase feldspar and the smoky ones are quartz. The black crystals are biotite or hornblende. Numerous other minerals can be present in granite. Granite is the best-known and most common igneous rock found at Earth's surface. Granite is not a local stone but the coming of the railway to Much Wenlock in the latter half of the 19th Century gave a much wider choice of stone to the monumental masons.
Your tasks
To log this cache, you will need to complete the tasks below. You can use information from the cache page and your observations at GZ to do this. Please message us with the info (rather than post it on your log). You can log a find once we have been sent a message. We may delete your log if your answer is way off the mark.
1 Examine the limestone blocks (these are the rougher ones) and describe:
- the appearance of the rock (texture, colour etc)
- any fossils you see. (There is a good example of one containing fossils to the left of the top of the door at the rear of the clock tower.)
2 Examine the sandstone panels (these are the carved ones).
- How does the sandstone differ from the limestone?
- The sandstone shows more signs of weathering than the granite (ie the basin). Why do you think this is?
3 Examine the granite basin.
- Estimate the size of the crystals.
- Why do you think that there are no fossils in the granite?
- Why do you think that granite was used for the basin, rather than limestone or sandstone?
As an optional extra post a picture of you and / or your GPS next to the clock tower.