Although the rock foundations in Lymm date back to over two hundred million years ago they have only looked the way they do today due to the happenings of the past 13,000 years. It was the effects of the last ice age which altered the appearance of the landscape in Lymm, in common with much of northern England. The main cause of effect was when the ice began to melt, as this would change the shape of the rock. It was in the Lymm area that the ice began melting around 13,000 years ago. The melted water from the glaciers would collect and carry debris which then battered and scoured the rocks to the basic shape they hold today. The areas of Lymm Dam, The Dingle and the Slitten Gorge were most likely a main local meltwater channel.
The rock foundations of Lymm comprises of three different types of rock. This is due to the environmental changes which have occurred over time. Each type of rock is named after the place in which they were firstly identified and studied. To begin with, the rock which is present in the Slitten Gorge is called Wilmslow sandstone. The soil here is also known as Stagnogley which is prone to wetness. If you were to climb the steps at the Southern end of the Slitten Gorge towards Whitbarrow road you would pass into the Helsby sandstone area of Lymm. This is redder in colour than the Wilmslow sandstone which it overlies. The Helsby foundations run southward through the village centre and the Dingle, and finish roughly halfway along Lymm Dam.
This final type of rock is known as Tarporley siltstone. It is made up of a much fine grained rock which reflects the environmental conditions at the time of its formation. The deposition must have been much quieter than previously allowing for fine particles to be deposited through the river system. The path on the western side of the Wishing Bridge at Lymm Dam is a great area to view the siltstone. The sedimentary layers are clearly visible through the deep channels whish are cut away through the rock.
The sandstone formations at Lymm Dam are one of the only two examples of its kind currently recorded in the UK. Its rarity is therefore a valuable contribution to Lymm Village and an attractive tourist spot.
The most interesting of rock features around Lymm Dam is the section of rock below St Mary's Church. This area is known as the 'Bluff' and has two important features. The first is what are called the NYE Channels. These are the deep channels which have been etched into the rock as the result of a particular type of sub glacial erosion from fast flowing meltwater. Undoubtedly these channels through the rock have been further embellished by the feet of sliding children through the years. The second feature is known as the Scallops which are the rounded steps in the vertical sections of the rock, again formed by the fast flowing meltwater.
On a walk around Lymm Dam today you will almost certainly spot a grey squirrel. The grey squirrel, although now very common, was only introduced to Britain in the 1850s after been brought over from North America. However, had you been walking round Lymm Dam somewhat two hundred million years early when the rocks were formed you may well have been more likely to spot a Chirotherium dinosaur. Footprints of the beastie have been discovered in north Cheshire sandstone quarries close to the Lymm area.
View details on history in Lymm.