Lornshill Academy Geography Department National Revision Physical Environments Limestone

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1 Lornshill Academy Geography Department National Revision Physical Environments Limestone

Chemical Weathering Rain is a weak acid. When it reaches the Earth s surface, it dissolves some of the minerals that make up rocks (especially calcium carbonate found in limestone).

2 Revision Notes for Rivers What you need to know: 1. How limestone is eroded 2. Formation of features 3. How people use limestone landscapes 4. Conflicts and solutions between land uses Process of Erosion Limestone is made of calcium carbonate and calcium carbonate suffers from chemical weathering and also freeze thaw weathering. Chemical Weathering Rain is a weak acid. When it reaches the Earth s surface, it dissolves some of the minerals that make up rocks (especially calcium carbonate found in limestone). Formation of Features Limestone Pavement When glaciers passed over the top of an upland limestone area, the topsoil was removed leaving an area of exposed rock. The following chemical action of rainwater dissolving the limestone, joints widen and deepened on the surface creating large blocks that look like pavements. The cracks between the blocks are called Grykes and the large blocks are called Clints. Scree Slope Frost shattering occurs when the water seeps into little cracks on the slope surface and freezes during cold winters. This causes pieces of rock to break off and fall down to the bottom of the slope. This broken material eventually builds up on the slope is called Scree and the slope is called a Scree slope.

Potholes and Swallow holes Potholes and swallow holes are formed where persistent widening of a major joint has occurred through weathering by a surface stream, which has disappeared underground.

As the surface water meets the impermeable underground rock, this can lead to the creation of underground lakes and streams.

This water filters through the rock and drops are deposited on the ceiling and floor of the caverns. Gradually the moisture is evaporated and the deposits on the ceiling and floor of caverns.

3 Potholes and Swallow holes Potholes and swallow holes are formed where persistent widening of a major joint has occurred through weathering by a surface stream, which has disappeared underground. Underground Caverns As the process of dissolving the limestone continues, underground sections of the rock may collapse creating underground caves. As the surface water meets the impermeable underground rock, this can lead to the creation of underground lakes and streams. Stalactites & Stalagmites Stalactites and stalagmites are found in underground caverns. Through chemical weathering particles of limestone are dissolved in solution by rainwater. This water filters through the rock and drops are deposited on the ceiling and floor of the caverns. Gradually the moisture is evaporated and the deposits on the ceiling and floor of caverns. Stalactites are deposits hanging from the ceiling. Stalagmites are coming up from the ground. Intermittent Drainage Intermittent drainage occurs on limestone areas where streams drain areas of impermeable rock carry on into limestone area and disappear through the permeable limestone. This interrupts the course of the stream on the surface. Gradually as the streams flow along the water table they emerge at the surface at a lower level and this water is called a spring. Gorge

4 As the caverns increase in size the amount of rock above it decreases. Eventually the rock becomes unstable and collapses into the cavern. This forms a deep-sided valley or gorge. Yorkshire Dales Land Uses Hill Sheep Farming Due to the steepness of the slopes, the cold temperatures and high rainfall, which limit the growing season and affect soil fertility, the area is mostly unsuited to crop farming since it would be almost impossible to use machinery such as combine harvesters. The only type of farming possible is hill sheep farming, with cattle occasionally being raised on lower, less steep land. Quarrying The main type of industry is quarrying for granite and slate for roads and roofs. Limestone is also quarried for use in the steel making elsewhere. The number of quarries operating has gradually been reduced in recent years Recreation, Leisure and Tourism The area is very attractive to tourists offering a variety of physical attractions such as the mountains and lakes for activities such as hill walking, mountain climbing, adventure holidays, water sports, fishing and general sightseeing. Land Use Conflicts & Recreation V Conservation Pollution from boats (discharging petrol) Noise pollution from engines (Vehicles & Boats) Caravans / trailers cause congestion Speed of boats can cause erosion to coast line through waves Excessive waves or heat can disturb marine life Walkers and mountain bikers cause footpath erosion Other forms of recreation can scare wildlife and damage plants Monitor pollution to lochs or mountains Enforce speed limit for boats to reduce waves Creating parking area to reduce congestion Create information posts / nature trails to educate the public Maintain footpaths cycle ways to reduce damage Inform public of vulnerable species and specific times i.e. mating or hatching time

5 Recreation V Forestry Areas closed off to public by Forestry Commission, especially during time of felling. Large areas of single type tree in large blocks, which can spoil the scenery. Felling can leave large areas of barren land, which can be very unattractive. Fires maybe started. Footpath erosion can damage the trees. Pollution from cars or people who use the forest. Large Lorries especially during felling can cause congestion. Provide walks / paths in forest to reduce damage to the trees. Provide mountain bike tracks, also creates additional form of income. Fell trees at off-peak tourism times; reduce impact on roads and scenery. Leave firefighting equipment (Brushes, spades, and contact telephone number). Maintain footpaths to prevent walkers going off into forest. Quarrying V the Rest Can be dangerous to the public (Quarries) Creates lots of visual pollution (Smoke / eyesore) Also noise and light pollution (blasting times and night working) Heavy lorries on roads cause congestion Dust from quarrying can damage crops or stain windows etc. Could be pollution leaks into rivers Consultation with public / residents Industry invests money into local communities i.e. build community hall Work carried out during off-peak tourist season to minimise loss of income Strict monitoring of pollution levels Money spent on conservation projects Shelter belt to screen industry Only allow one blast a day (Quarry), advertise times to warn people. Tourism V Farming Walkers can cause damage to dykes and fences Some damage to crops or farmland Pet dogs can worry sheep or other farm animals Gates can be left open allow animals to escape Farmers may prevent walkers or cyclist crossing their land Litter can cause problems for animals or machinery Fit sties for walkers so dykes and fences aren t damaged Self-shutting gates prevent animals from escaping Maintained paths for walker of cyclists prevent damage to crops Information on lambing times or restricted access at these times prevents problems Information for public about farming considerations Access to room laws for walkers

6 Tourist V Resident: Congestion from tourist vehicles (caravans & camper vans) Increase in air pollution from exhausts Holiday homes make local housing too expensive for locals to buy If possible wider roads and create designated parking Competition for goods keeps prices down Areas where second homes are not allowed New built homes for locals only Tourist V Tourist: Noisy pursuits can disturb quite for more peaceful pursuits (water sports V fishing, quad biking V pony trekking) Erosion of footpaths (Mountain bikes and scramblers cause far more damage than walkers) Litter & fires cause pollution of the environment Large campsites can spoil scenery Designated areas for fishing & speed boating Fines for litter or other pollution Information on activities and location of activities Planting trees to screen camp sites (shelter belt) Create fisheries in quiet areas (manmade lakes with stocked fish)

Introduction The Exam...vii. 1. Maps and Photographs...1

Introduction The Exam...vii. 1. Maps and Photographs...1 CONTENTS Introduction The Exam...vii Section 1...vii Section 2...viii 1. Maps and Photographs...1 Grid references on maps...1 Scale and measuring distance...3 Directions on maps...5 Area on maps...6 Height