small tubular water-worn passages. There is evidence of several sea levels along the Silverdale coast, and there is an almost perfect circular phreatic tube cave worn by water pressure action.
The many limestone pavements in the area were scraped by ice and eroded by water and rainfall into their present form of clints – smooth surface blocks eroded over time – and grykes – the deep fissures between the clints. Solution pockets of varying sizes can also be seen on the surface where rainwater has created hollows by dissolving the limestone. Where the pavements are tilted, surface runnels are formed by water. These are especially pronounced on Farleton Fell and Hutton Roof Crags, where the rounded rundkarren are among the best examples in Britain. These were formed when the rocks were covered by a layer of vegetation and water draining away underneath the vegetation wore the limestone into its present attractive patterns. Sharp-edged rinnenkarren were formed where the rocks were open to erosion directly by the elements. These are rare in Britain and are best seen at The Rakes of Hutton Roof Crags.
During the last Ice Age many limestone boulders were moved and deposited on other limestone beds, and there are many examples of these perched boulders, or erratics, in the area. (They are so called because they are not derived from the rock upon which they lie.) Sometimes the ice moved rocks from further afield before depositing them; Shap granite erratics can be seen on some of the walks.
In geological time the limestone was covered by beds of red sandstone, long since removed by erosion. An interesting feature that developed at this time was caused by water seeping through the sandstone and becoming impregnated with minerals which were then deposited in the limestone caves below. This is explains the presence of copper and haematite (iron ore) which were mined in several parts of the area, especially at Crag Foot, where layers of brecciated sandstone filled the phreatic passages.
Karren grooves at The Rakes (Walks 16, 18)
Industry through the ages
Early settlers
The earliest settlers chose the well-drained terraces of Warton Crag, close to springs of good water. Dog Holes, above Crag Foot on Warton Crag, is archaeo-logically interesting but there is no public access. At the foot of a small shaft there are several galleries which have yielded a rich collection of remains, the earliest dating from Late Pleistocene times. Beaker-ware, flints and human remains from Neolithic times, Bronze Age pans and enamelled bronze-work and Roman pottery have all been recovered. It seems that the cave was used for human habitation over a very long period of time. Other archaeological remains have been found at another Dog Holes, on Haverbrack, but not in the same quantity as at Warton.
Mining
Copper was scarce in the area and therefore highly prized. Copper ore was mined in Elizabethan times near Jenny Brown’s Point, and a little later near Storth. Between 1800 and 1830 copper was mined at Crag Foot by Cornish miners. The ore was smelted at Jenny Brown’s Point in the smelt mill built at the end of the 18th century, using engines transported from North Wales.
The Higher and Lower Warton Mines at Crag Foot enjoyed a further lease of life between 1836 and 1840 when haematite was mined for reddle, a very powerful red dye used in the manufacture of paint and for colouring doorway threshold stones. The ore was floated, dried, crushed and screened, then roasted to give different colours. Leighton furnace was built in 1713 and operated into the 1800s.
Coppicing
Until around 1914 most of the woodland in this area was managed on the coppice-with-standards system, in which the standard trees, particularly oak, were allowed to grow normally, while the surrounding underwood, usually of hazel, was cut regularly. The felled tree stumps produced a growth of straight, slender poles of varying thickness which was then harvested for a wide range of uses including charcoal manufacture. The coppiced wood was also used for the flourishing bobbin industry of South Westmorland. The term coppice, or copse, derives from the French word couper – to cut. During the First World War many of the standards were cut down and coppicing went into decline.
Wildlife
The woodlands support a prolific but shy wildlife. Deer are prevalent over the whole wooded area; alongside the native red and roe deer are small numbers of shy, pale fallow deer whose forebears have escaped from the introduced Dallam Park herd. Although deer can often be seen, they prefer undisturbed surroundings and usually keep away from the popular paths. Walkers should be aware that ticks from red deer have been known to carry Lymes Disease, a particularly unpleasant illness. However, cases are very rare. It is sensible to wear long trousers, and if you have flu-like symptoms after a bite, or a red circle around the bite, consult a doctor. Dogs can also pick up the ticks.
Fallow deer
Other wildlife in the area include red squirrels, which can still be seen in some of the woodlands; badger setts are not uncommon, but you will only see these shy nocturnal creatures if you are very lucky around twilight.
The limestone area is renowned amongst naturalists for its exceptionally interesting flora, protected in several extensive reserves. Many species of orchids can be seen in late spring and early summer. The sheltered limestone crevices, or grykes, provide a perfect habitat for a range of interesting plants, some of which you would expect to see on a woodland floor. Often, you will see flowers here when they are long past their best in more open surroundings.
Particular plants to look for in the grykes are the many species of fern: hart’s tongue, hard shield and male; wall and maidenhair spleenworts; and polypody. Also present are the rare rigid buckler fern and limestone fern, and the nationally scarce blue moor grass. Limestone pavement is also an ideal habitat for a range of uncommon plants including angular solomon’s seal, lily-of-the-valley and several orchids including the dark red helleborine. All plants are protected by the Wildlife and Countryside Act, which makes it an offence to pick or remove any wild flower without the owner’s permission.
Crevices in the limestone are a haven for ferns
Butterflies and moths thrive on the limestone grassland and you may see the diminutive small heath or the larger dark green fritillary. Birds to look for are the skylark, willow warbler and yellowhammer.
The Leighton Moss Reserve was established by the Royal Society for the Protection of Birds in 1964, and in 1974 it purchased an additional 6000 acres of the marshland on the edge of Morecambe Bay between Hest Bank and Arnside Point to create one of the most important bird reserves in the country. Over 270 bird species have been recorded on the reserve, including the elusive bittern and the striking avocet.
Many walkers who are not especially interested in birds do not realise the significance of the intense activity which takes place on the estuary and the moss. It is of international importance. Many birds use the estuary as a staging post on a long migratory journey, such as greenshank and whimbrel on their way from the Arctic to Africa. White wagtails pass in spring on their way to Iceland, while pink-footed geese fly over from their breeding grounds below the icecaps of Central Iceland. It is worth a special visit to the coast in winter to see the vast flocks of dunlin, knot, oystercatcher, blacktailed godwit and redshank which gather on the edge of the tide. In spring many of them migrate northwards, to Scandinavia and Russia, to breed. Shelduck, a colourful bird which finds its food in the estuary mud, is often seen in large numbers. They breed in the area, often inland in rabbit holes, and make a strange moult migration to Heligoland in Germany, returning in mid-September.
