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Unique landforms occur at plate margins Location and formation of ocean trenches, shield volcanoes, composite volcanoes and fold mountains.

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Presentation on theme: "Unique landforms occur at plate margins Location and formation of ocean trenches, shield volcanoes, composite volcanoes and fold mountains."— Presentation transcript:

1 Unique landforms occur at plate margins Location and formation of ocean trenches, shield volcanoes, composite volcanoes and fold mountains.

2 Volcanoes are Hazards resulting from tectonic activity. Their primary and secondary effects are positive as well as negative. Responses changes in the aftermath of an eruption CASE STUDY: Soufrierre Hills, Montserrat

3 Trenches are found adjacent and parallel to continents and island chains. At least 22 trenches have been identified although not all are classified as major. Of this number, 18 are in the Pacific Ocean, three in the Atlantic Ocean, and one (the Java Trench) in the Indian Ocean. Depths of major trenches exceed 18,000 feet, and vary from 10 to 22 miles in width. The deepest is the Challenger Deep, 35,810 feet deep, in the Marianas Trench. The depths of many trenches are greater than the elevation of the world's highest mountain.

4 Ocean trenches happens at areas where two plates collide, a DESTRUCTIVE plate margin. The denser oceanic crust to sinks or slips beneath lighter continental crust. Trenches are formed by the process of SUBDUCTION. Oceanic crust/plate is made up of heavy material (basaltic rocks). Along a collision plate boundary, thinner, denser oceanic crust is squeezed down and subducted along the subduction zone and melts in the magma of the upper mantle. Subduction produces a deep Ocean Trench on the ocean floor, parallel to the plate boundary.

5 Destructive Margin

6 Describe the differences in shape between Volcano A and B. One is a SHEILD volcano the other is a COMPOSITE volcano

7 COMPOSITESHIELD Steep sidesGentle sides NarrowerWide Violent EruptionsGentle eruptions Ash and Lava Lava and a little ash Lava thick acidicRunny basic Erupts infrequentlyErupts frequently

8 What do you notice about the location of the two volcanoes? How do the relative positions of the volcanoes help understand their different shapes?

9 Composite Cone The volcano is built up of alternate layers of LAVA and ASH. They can explode with great violence. Mt St Helens - USA Conelet Dyke Crater Ash layer Lava Layer Flank eruption Lava Flow Crust Pyroclastic Flow

10 Composite Cone The volcano is built up of alternate layers of LAVA and ASH. They can explode with great violence. Mt Ranier - USA Mt St Helens - USA

11 Shield ( Basic) Cone Shield Volcanoes are enormous features built up only from layers of lava. They produce lots of lava but they tent not to erupt violently. Mauna Loa Hawaii -USA 250 miles 10,000m Composite volcano to scale Layers of LavaLava Flow

12 Shield ( Basic) Cone Shield Volcanoes are enormous features built up only from layers of lava. They produce lots of lava but they tent not to erupt violently. Mauna Loa Hawaii -USA

13 Describe how FOLD MOUNTAINS are formed. Foundation June 09 The plates move together (a collison margin) forcing the sedimentary rocks upwards in a series of folds Over millions of years the sediments were compressed into sedimentary rocks such as sandstone and limestone. Rivers deposited huge quantities of sediments in depressions called geosynclines

14 Explain the formation of young fold mountains. Higher June 09

15 Statements relating to existence of large depressions calledgeosynclines. The erosion of material from land surface by rivers / accumulation of material on seabed. Further layers of material being added as the erosion process continues / being compressed into rock by weight of particles / sea above. The movement of plates together – compressional (destructive) boundary/sediment being crumpled into fold mountains / anticlines and synclines forming. (4 marks) Diagrams are worthy of credit.

16 Level 1 (Basic) (1-2 marks) An idea of how fold mountains form. Separate statements. Partial sequence – likely to refer to end of it, rather than the start, e.g. material collects under the ocean. Plates shift together and material is folded into mountains. Level 2 (Clear) (3-4 marks) Describes clearly how fold mountains form. Linked statements. Complete sequence – links aspects of last two points to first two, e.g. material is eroded from the land by rivers and transported to the sea. Here, in a geosyncline the material is deposited and compressed by the weight of further layers and the water into rock. The plates move together and the material folds creating anticlines and synclines present in fold mountains.

17 Collision Margin E.g. The Himalayas Plates: Indo-Australian and Eurasian

18 Use an atlas to complete the labels.

19 TRUE OR FALSE  There are no fold mountains in Africa.  The land next to the Pacific Ocean has many fold mountains.  The Andes are found at a destructive plate boundary.

20 Describe the world distribution of young Fold Mountains. Foundation June 09

21 Any 2 valid facts from Figure 4, Credit positives only. Max one mark for plate boundaries using correct context. there are a lot along the west coast of the Americas; they cluster around the Pacific Ocean; there is a band to north, east and west of India; there is only one range in North Africa.

22 People use these landforms as a resource and adapt to the conditions within them People use these landforms as a resource and adapt to the conditions within them.

23 Give a reason(s) why one type of human activity happens in fold mountain areas. Name of human activity (2 marks)

24

25 Foundation June 09

26 Valid human activities are arming, forestry, tourism, HEP and industry. Farming and tourism likely to be dominant. No mark for naming human activity. 2×1 for description, e.g. Farming favours south facing slopes (1). Cattle are kept on high slopes during summer (1) and brought down to lower areas where they are kept inside during the cold, snowy winter (1).

27 Level 1 (Basic) (1-2 marks) An idea of how fold mountains form. Separate statements. Partial sequence – likely to refer to end of it, rather than the start, e.g. material collects under the ocean. Plates shift together and material is folded into mountains. Level 2 (Clear) (3-4 marks) Describes clearly how fold mountains form. Linked statements. Complete sequence – links aspects of last two points to first two, e.g. material is eroded from the land by rivers and transported to the sea. Here, in a geosyncline the material is deposited and compressed by the weight of further layers and the water into rock. The plates move together and the material folds creating anticlines and synclines present in fold mountains.

28 Add a sentence to match each box

29 First box – statement relating to existence of large depressions (geosynclines); the erosion of material from land surface by rivers ; accumulation of material/sediment on seabed. Second box – statement relating to further layers of material/sediment being added; being compressed into rock by weight of particles / sea above. Third box – statement relating to movement of plates together; sediment being crumpled into fold mountains; anticlines and synclines forming. 3×1. One acceptable statement per box. Foundation June 08

30 Mount St Helens is part of the Cascade Range of young fold mountains. Complete the sentences below to explain how fold mountains are formed. Choose the correct words from the list. Eroded sandstone apart plate boundaries together deposited ocean ridges granite Fold mountains are formed along.............................. Over millions of years, thick sediments were.......................... in huge depressions. The sediments were compressed into solid rocks such as................... The plates moved............................ forcing the rocks upwards into fold mountains. (4 marks) Describe the human activities in an area of young fold mountains that you have studied (4 marks) Foundation June 04

31 Fold mountains are formed along plate boundaries. Over millions of years, thick sediments were deposited in huge depressions. The sediments were compressed into solid rocks such as sandstone. The plates moved together. forcing the rocks upwards into fold mountains. (4 marks) Describe the human activities in an area of young fold mountains that you have studied (4 marks) Point mark (4 × 1) or developed points. Reserve of one mark for example (not Cascades) e.g. Alps, e.g. In the Alps (1) there are ski resorts (1) and lots of people go on holiday in the winter. In summer they visit the lakes (1) e.g. Lake Como. (1) HEP (1) uses the fast running streams (1). Hay and vines are grown (1) in the valleys in summer and cattle graze the hilltops. (1) Max 2 on tourism. Max 2 for list. Foundation June 04

32 What type of volcano is Mount Fuji? Shield Add labels to describe the volcano. Box X – crater / flat top; box Y – steep sides / cone shaped. Foundation June 09

33 Volcanoes can occur in fold mountain ranges. Figure 5, on the insert, shows Mt Fuji in Japan. In the space below, draw a labelled sketch of Figure 5 to show the features of this volcano. Higher June 09 1 mark for drawing sketch shape – which should resemble clearly the profile in Figure 5. Use S for shape mark. 2×1 for appropriate labels – such as crater / shape of land here; steep sides; cone shape, ridged appearance. 3 marks Higher June 09

34 Volcanoes can occur in fold mountain ranges. Figure 5, on the insert, shows Mt Fuji in Japan. In the space below, draw a labelled sketch of Figure 5 to show the features of this volcano. Higher June 09

35 Many earthquakes have occurred around the edges of the Pacific Ocean. There have been many earthquakes in Northern Europe. There is a line of earthquakes through the middle of the Atlantic Ocean. (3 marks) June 05

36 Study Figure 11, on the insert, photographs of the Franz Josef glacier area in New Zealand. Describe how the area provides an opportunity for one tourist activity. (2 marks) Describe the environmental problems caused by tourist activities in upland glaciated areas. (4 marks) June 09

37 Study Figure 11, on the insert, photographs of the Franz Josef glacier area in New Zealand. Describe how the area provides an opportunity for one tourist activity. (2 marks) Describe the environmental problems caused by tourist activities in upland glaciated areas. (4 marks) June 09 Any 1 valid opportunity, e.g. the glacier offers a unique area to visit / see firsthand (1) and experience walking on it/ice is clearly very deep / formed into shapes. (1) Quad-biking (1) is another activity – on the area near to the glacier and allowing own transport to view glacier in a different way. (1) (2 marks) Erosion of land surface is likely with quad-biking; disturbance to wildlife and impact on habitat; the number of visitors being encouraged to fairly remote areas and the impact of these in areas where glaciers are present; litter and noise. (4 marks) June 09


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