Walking in the Yorkshire Dales: North and East. Dennis Kelsall

helped in the creation of one of the loveliest landscapes in the country.

      Although numerous lanes and tracks wind deep into the heart of the Dales, it is really only the leisurely freedom of pedestrian exploration that enables a true appreciation of its unique charm. This, the second of two volumes, is a wanderer’s guide to the northern and eastern parts of the area, savouring its ups, downs and endless in-betweens. The various walks seek out spectacular viewpoints, dramatic landforms, curious natural features and attractive hamlets and villages, but more than that, they simply delight in the subtly changing scenery. There is something for everyone in this guidebook, from gentle walks along valleys and hillsides, to more demanding upland romps that take in the high hills and remote moors of the hinterland. For the newcomer in particular, this is an invaluable companion. In addition to the route descriptions, there is background information on many of the features encountered along the way. While some routes are inevitably popular, many others take you off the beaten track to less-visited spots, and even those who know the Dales may well find new corners.

EVOLUTION OF THE LANDSCAPE

Geological history

      The unique character and unquestionable charm of the Yorkshire Dales has its roots in the underlying bedrock, much of which was created during the Carboniferous period 300 million years ago. At a time when, in other areas, massive coal, gas and oil fields were being laid down in the accumulating detritus of humid forest swamps, the area which has become the Dales lay beneath a shallow tropical sea. Here, the broken shells of countless marine creatures settled to form a bed of limestone over 200m thick. Known as the Great Scar Limestone, it dominates the scenery of the southwestern corner of the Yorkshire Dales National Park and underlies its central core.

      Eventually, river deltas encroached from the north, washing mud and sand across the coastal shelf. But this was a period of cyclically changing sea levels, creating sequential strata of shale and weak sandstones, repeatedly topped off by limestone as lagoon conditions intermittently returned. Each band is only around 12m thick, but the build up over aeons formed a kind of ‘layer cake’, over 300m deep.

      The River Ure at Slapestone Wath (Walk 28)

      Named the Yoredale Series, because of its appearance in the valley of the River Ure – Wensleydale – this banded rock forms the basis of the northern portion of the national park, and extends further south as higher peaks and ridges. The upper levels of the layering culminate in a hard, impervious sandstone known as millstone grit, reflecting one of its uses, and the remnants of this form the southern hill tops and the high ground of the northern fells.

      Although originally laid down in neat, horizontal bands, these rocks were subsequently folded by a massive earth movement that created the Pennines. Fractures separated the section underlying the Yorkshire Dales, known as the Askrigg Block, from the rest of the mountain chain, and it was pushed up from the south and the west, putting the Carboniferous strata of the block far above the younger rocks that lie to the south. The block tilts gently backwards, and whereas weathering has exposed the older limestones in the southwest of the area, the more recent Yoredale rocks remain on top to the northeast.

      The lines of fracture are dramatically evident in the three main Craven Faults, which cut across the southern part of the national park. Giggleswick Scar – the line of towering cliffs overlooking the B6480 west of Settle – is part of the South Craven Fault, which continues its line southeast towards Skipton. The Mid-Craven Fault is marked by a long line of cliffs of which Malham Cove and Gordale Scar are a part, while the North Craven Fault runs parallel to it at the southern lip of Malham Tarn.

      In a few places, the limestone of the block has been worn away to expose rocks from an even earlier era, the Ordovician, which, unlike the even Carboniferous formations, are extravagantly crumpled, and consist of slates, grits and mudstones. These can be seen in the quarries of Ribblesdale and around Ingleton, and are also exposed as an impervious basement layer in the southern valleys, perhaps most vividly in Thornton Force and along the Ingleton Falls.

      The character of the Howgills clearly sets them apart from the rest of the Dales, and with the Middleton Fells, they are separated from the Askrigg Block by another fracture line – the Dent Fault. This runs in a rough north–south line east of Sedbergh, but here the displacement has been in the opposite direction, elevating the older rocks that lie to the west. Geologically these hills are part of the Lake District, and are composed of much-folded metamorphosed slates and grits from the Silurian period, about 100 million years older than the Carboniferous rocks making up the Askrigg Block. Their grassy flanks sweep steeply upwards from deep ravines to broad, rounded tops, whose long interconnecting ridges, once attained, offer immensely satisfying walking.

      Field barn above the River Swale below Ivelet Side (Walk 21)

      Some of the most spectacular scenery of the national park is to be found in the areas dominated by the Great Scar Limestone – Malham Cove, Gordale, Kingsdale, Twisleton, Lower Ribblesdale and the middle reaches of Wharfedale. Towering lines of white cliffs and scars, shake holes, sinks, potholes, caves, disappearing and resurgent streams and rivers, dry valleys and waterfalls, clints and grikes, are all features of this remarkable karst landscape. Overlooking the fault lines, the cliffs result from the upward movement of the Askrigg Block, but the terraces along the valley side are due to the relative resistance of different layers to erosive weathering. A similar picture is seen further north in the Yoredale Series, where the successive bands of limestone are comparatively harder than the intervening strata of sandstones, producing the stepped profile that is so characteristic of Wharfedale and Swaledale. It is this same process that gives rise to the many spectacular waterfalls of the region, the water cascading over a lip of hard limestone, but undercutting into the softer rock that lies below.

      The most intriguing features of karst landscapes are those that result from the solubility of the bedrock in rainwater. The rain’s slight acidity dissolves the stone, exploiting crevices and vertical stress fractures, and ultimately creating the awe-inspiring potholes and caves for which the area is famous. Whole rivers are swallowed into the ground, either in abruptly sensational falls such as Gaping Gill, or merely disappearing intermittently into their beds, as does the River Nidd in its higher reaches.

      Just as magical are the Nidd’s resurgences lower down, the river having coursed between two points deep underground in the dark and constricted passages and fissures that are the province of intrepid potholers and cave divers. At Stump Cross, these dramatic passages are sufficiently accessible to have been opened as show caves, allowing visitors to marvel at fantastic stalactites, stalagmites and other formations, created as incessant drips of lime-rich water evaporated over millennia, leaving the lime behind. Occasionally, similar deposits are also seen on the surface in the form of tufa, where calcite is precipitated from the cascading water. And at How Stean Gorge, the river runs through a dramatically narrow canyon, which is explained as a collapsed cave.

      While streams, even after rain, are something of a rarity on the limestone uplands of the south, dry valleys are not. Like Trow Gill and Conistone Dib, they can be stunningly spectacular – deep, narrow ravines, stepped with the walls of ancient waterfalls. Occasionally, following heavy rain, rivulets might briefly cascade through, but these bear little resemblance to the overwhelming torrents of meltwater that created them, as the last ice age came to an end. Where rivers flow uninterrupted today, they have usually worn the valley down to a bedrock of impervious stone, or else flow over deposits of clay dumped by retreating glaciers.

      The extensive clint fields, or limestone pavements, also have their origins in the last ice age. Initially levelled to a bedding plane and stripped clean by glacial action, they were re-covered with clay debris when the ice finally retreated. Seeping rainwater subsequently picked out vertical lines of weakness to form the grikes, fragmenting the pavement into blocks – the clints. Eventual erosion of the thin soil cover, perhaps as a result of woodland clearance, or grazing by early man’s livestock, has once more revealed the bare pavements that are now such a striking feature. Accumulating soil