SM GEO 11 Support Pack for Geomorphology geographical

Study & Master Support Pack | Grade 11 CAPS Geography Geomorphology – geographical knowledge This support pack for the Geomorphology – geographical knowledge module in the Geography Grade 11 CAPS curriculum provides valuable revision activities. All activities have the answers provided. Learners can work through these individually at home or these could form the basis of a catch-up class or online lesson. You have permission to print or photocopy this document or distribute it electronically via email or WhatsApp. For more information on our Study & Master CAPS-approved  textbooks and valuable resource materials, visit www.cambridge.org Brighter Thinking | Better Learning

Geomorphology – geographical knowledge QUESTION 1 d) Describe how humans might use this Refer to Figure 1 and answer the questions. landscape. (2) A X Y 5. For D–E: 1 B 2 a) Identify the slopes X and Y. (2) 3 C D E b) Describe how they were formed. (3) c) Describe how humans might use this landscape. (3) Figure 1 [30] 1. a) Identify the landforms A, B, C, D and E. (5) QUESTION 2 b) Identify slope elements 1–3. (3) 1. Read the two extracts below and on the next page 2. Describe the difference in the rock layers A–C and and complete these questions. D–E.  (2) a) In your own words, write a few sentences 3. Give an example of the type of rock that caps A explaining how the Drakensberg formed. and B and classify this type of rock.  (2) b) Name two rivers that erode the Drakensberg. 4. For A–C: c) Describe the climate of the Valley of a a) Identify the type of landscape. (1) Thousand Hills. In what way has the b) Describe how it was formed. (4) climate contributed to the formation of the c) Name and describe the most likely model of landscape? slope development. (3) 2. Copy and complete the table. Drakensberg Valley of a Fish River Canyon Three Sisters Thousand Hills Type of landscape Rock layers Stage of development Use The mighty Drakensberg or uKhahlamba is a World Heritage Site The break-up of Gondwanaland was southern Africa’s most spectacular display of geological forces. The great event took place 180 million years ago. It produced an outpouring of lava that covered most of southern Africa and which was about 2 000 m thick. The majestic Drakensberg is now all that’s left of this huge lava field. It has shrunk away as rivers have eaten into it from all sides. And it continues to erode at a rate of 1,5 m every 1 000 years. The name Drakensberg translates to ‘Dragon Mountain’. The Dutch Voortrekkers called it this because of its looming shape and size. The Zulus call it ‘Barrier of Spears’ because of its spear-like peaks. The Drakensberg area is a UNESCO World Heritage Site. Its scenic beauty, steep cliffs and rugged peaks make it a tourist attraction and a popular place for hiking and climbing. Profile from the Drakensberg to Durban. Note the sills and dykes. A UNESCO (United Nations Educational, Scientific and Cultural Organization) World Heritage Site is a place of cultural or natural importance in the world. South Africa has eight World Heritage Sites. Two of these are geological features. S T U DY & M A S T E R G e o m o r p h o l o g y – g e o g r a p h i c a l k n ow l e d g e 1

The Valley of a Thousand Hills: it inspires Because the magma cooled slowly, the minerals were writers and challenges runners concentrated in layers, making it one of the richest ‘There is a lovely road that runs from Ixopo into the hills. mineral deposits in the world. Originally it was thought These hills are grass-covered and rolling … that the intrusion was a single giant lopolith, but it is in The road climbs seven miles into them, to Carisbrooke; fact, a cluster of lopoliths. These lopoliths are up to 8 km and from here, if there is no mist, you look down into one thick. of the fairest valleys of Africa.’ The opening lines of Alan Paton’s Cry the Beloved Country describe the Valley of a Thousand Hills. This BOTSWANA Limpopo rolling carpet of green hills has been carved by the Mgeni River and its tributaries. Uplift raised parts that were NAMIBIA Pretoria once the sea floor. And slowly the rivers have eroded the North West SWAZI- resistant sandstone, all the way down to its basement of LAND granite and gneiss. The Old Durban–Pietermaritzburg Road runs through Free State KwaZulu- the Valley of a Thousand Hills and is the route of the Natal Northern Cape Comrades Marathon. Every year, thousands of runners LESOTHO endure the 96-km run with its uphill and downhill slopes. The direction of the race alternates every year: one year it begins in Durban (the overall route is uphill) and the next year in Pietermaritzburg (the overall route is downhill). Eastern Cape 0 400 On the uphill run, there are the Big Five hills which Western Cape kilometres runners must conquer: Cowie’s Hill, Field’s Hill, Botha’s Hill, Inchanga Hill and Polly Shorts. The Valley of a The region of the Bushveld Igneous Complex Thousand Hills is also home to the Dusi Canoe Marathon on the Msunduzi and Mgeni Rivers. The ring dyke structure of Pilanesberg The Pilanesberg in the North West province is named QUESTION 3 after Pilane, the Bakgatla chief who ruled in the area Read the two features ‘The Bushveld Igneous Complex’ in the first half of the 1800s. The Pilanesberg is often and ‘The ring dyke structure of Pilanesberg’. Then described as an extinct volcano. About 1 300 million years ago, the featureless plains of the region were dominated answer the following questions. by a towering volcano, which has now been worn away. 1. Which is older, the Pilanesberg, or the The volcano was 7 000 m tall, significantly higher than Magaliesberg? Give a reason for your answer.  (3) Kilimanjaro. But Pilanesberg is also a very rare formation 2. a) Briefly explain how the Magaliesberg called a ring dyke complex. It was formed from a magma mountain range was formed. (3) intrusion underneath the volcano. When this intrusion b)  Classify the Magaliesberg ridges as cuesta, became exposed, it produced concentric rings of hills. homoclinal ridge or hogback. (1) c)  In Figure 4, identify the dip slopes and the scarp slopes of the Magaliesberg. (2) d)  Name two strata of unequal resistance that form this range. Which is the erosion- resistant rock/layer? (3) 3. a) Explain and compare the terms ‘lopolith’ and ‘dyke’. (2×3) b)  Which is formed from silica-rich and which from silica-poor magma? (2) [20] The Bushveld Igneous Complex The Bushveld Igneous Complex (BIC) spans parts of A relief map of the Pilanesberg and the Magaliesberg, two Limpopo, North West, Gauteng and Mpumalanga important geological landforms in North West province provinces. It was formed 2 billion years ago by layered igneous intrusions. 2 S T U DY & M A S T E R S U P P O R T PA C K

QUESTION 4 QUESTION 5 Read the case study below and complete these Read the feature below. Then answer the questions that questions. follow. 1. Identify the dip slopes and the scarp slopes in the China’s giant landslide: natural or human- photograph of the Magaliesberg. made disaster? 2. Give the dip angle range for cuestas. In August 2010, China’s Gansu province had the worst 3. Explain what caused the Magaliesberg strata to landslide in 60 years. Two days after the landslide 702 tilt. Classify the event as faulting or folding. people were dead and another 1 042 were missing. 4. List the three types of rock that make up Chinese authorities called it a ‘rain-triggered’ slide. For the Magaliesberg strata and classify them as years officials had been warning that both heavy tree- felling and rapid hydro-development were making the sedimentary, igneous or metamorphic. Which of area around Zhouqu vulnerable to mass movements. the three is erosion resistant? Source: Adapted from: news.discovery.com 5. Describe how the ridge erodes, using the term ‘scarp retreat’. [12] 1. Define these terms: landslide, mass movement.(2) 2. Explain why mass movements are often ‘rain- triggered’.  (2) The Magaliesberg cuestas 3. Explain the human contribution to the landslide The Magaliesberg mountain range runs from Tshwane/ by: Pretoria in Gauteng to Pilanesberg in the North West a) tree-felling(2) province. The Magaliesberg has a long geological history. Three billion years ago, its sediments of quartzite, shale b) hydro-development.(2) and dolomite were deposited in an inland sea over a 4. What action could the Chinese authorities have period of 300 million years. Then, one billion years ago, taken to avoid the disaster? (2) a huge upwelling of magma took place. It produced what [10] is known as the Bushveld Igneous Complex – an igneous intrusion that is the source of South Africa’s platinum QUESTION 6 wealth. The weight of the liquid rock intrusion pushed Match these terms to labels 1–3 on Figure 2 below: down on the sediments below it and tilted up giant slabs of rock. The broken, raised edges formed the scarps. elevation, relief, and slope. [3] 3 2 1 000–1 800 m West East 1 up to 1 500 m up to 3 500 m Great Escarpment Interior Plateau Great Escarpment Figure 2 South Africa’s topographical profile The Magaliesberg, flanking Hartebeespoort Dam S T U DY & M A S T E R G e o m o r p h o l o g y – g e o g r a p h i c a l k n ow l e d g e 3

QUESTION 7 QUESTION 8 Refer to Figure 3 and 4. Refer to Figure 5. 1. Identify the type of landform. 1. Identify mass movements A–D. For each, list the 2. Identify two types of slope, four slope elements type of slope material and briefly describe the way and the knickpoint. the material moves. 3. Specify the climate of the region. [9] 2. Order mass movements A–D from slowest to fastest moving. [10]  [Total: 118 marks] crest – shaped by weathering and soil creep cliff – shaped by rock falls talus slope – shaped by weathering knickpoint – marks a sharp change in gradient pediment – shaped by sheetwash Figure 3 The elements of a slope and processes that shape Figure 4 A landform in Utah, USA them A B C D Figure 5 A–D Examples of mass movements 4 S T U DY & M A S T E R S U P P O R T PA C K

Answers QUESTION 1 is formed by erosion of less-resistant rock ✓ 1. a) A = mesa; ✓ B = butte; ✓ and the dip slope is protected by the layer of C = conical hill; ✓ resistant rock. ✓ (3) D = homoclinal ridge/hogback; ✓ c)  Farming is not feasible on the slopes – the scarp E = cuesta ✓ (5) slopes are too steep ✓ and the soil is too thin b) 1 = cliff/scarp/free face; ✓ on the dip slopes. ✓ But farming can take place 2 = talus slope/debris slope; ✓ in the valleys between the ridges. ✓ (3) 3 = pediment ✓ (3) [30] 2. A–C rock layers are horizontal; ✓ QUESTION 2 D–E rock layers are tilted/inclined. ✓  (2) 1. a) The break-up of Gondwanaland 180 million 3. dolerite; ✓ it is igneous rock ✓  (2) years ago triggered volcanic activity and an 4. a)  Karoo landscape ✓ (1) outpouring of basalt. The Drakensberg is the b)  It was formed from a canyon landscape ✓ as eroded remains of a very thick layer of basalt rivers carved deep ✓ into the rock layers. As that covered most of southern Africa. The erosion progressed, the valleys widened ✓ joints in the basalt have produced the steep- and the plateaus eroded away. ✓ (4) sided blocks of the mountain. ✓✓ c)  scarp/parallel retreat/backwasting: ✓ the b) for example, Senqu/Orange/Gariep River; slope angles and lengths stay constant ✓ as Tugela/uThukela River ✓✓ the slope recedes (is eaten back) ✓ (3) c) Moist and warm. The high temperatures d)  The flat, eroded valleys ✓ are suitable for sheep contribute to chemical and biological or goat farming. ✓ (2) weathering. The high rainfall causes 5. a)  X = scarp slope; ✓ Y = dip slope ✓ (2) sheetwash erosion and mass wasting, which b)  Tilted rock layers eroded at different rates to form the rounded hills. ✓✓ form asymmetrical ridges. ✓ The scarp slope 2. See the table below. Drakensberg Valley of a Thousand Fish River Canyon Three Sisters Hills Type of landscape basaltic plateau ✓ hilly landscape ✓ canyon landscape ✓ Karoo landscape ✓ Rock layers basalt and sandstone granite and gneiss sandstone and shale dolerite and sandstone (equal resistance) ✓ (equal resistance) ✓ (unequal resistance) ✓ (unequal resistance) ✓ Stage of mature ✓ young to mature ✓ young to mature ✓ old ✓ development Use • a tourist attraction, • a place of settlement a tourist attraction, for a sheep and goat especially for hikers and agriculture hikers or viewers ✓ farming area ✓ and climbers • the hills make a • caves were inhabited challenging course by the Khoisan for the Comrades thousands of Marathon years ago ✓✓ • its two main rivers host the Dusi Canoe Marathon ✓✓  [24] S T U DY & M A S T E R G e o m o r p h o l o g y – g e o g r a p h i c a l k n ow l e d g e 5

QUESTION 3 3. a) The roots of trees hold soil and regolith in 1. Magaliesberg; ✓ it was formed by the magma place. ✓ The removal of vegetation/trees intrusions of the BIC ✓ which are a lot older than speeds up erosion. ✓ the Pilanesberg ✓  (3) b)  (Any two.) For hydro-development, rivers 2. a)  The weight ✓ of the BIC magma intrusions are dammed in steep valleys. ✓ Slopes are pressed down on the sediments ✓ deposited sometimes oversteepened ✓ with construction. in an inland sea, causing them to crack and The dammed river can soak the slopes as tilt. ✓ (3) water levels rise. ✓ b)  cuesta ✓ (1) 4. For example: avoiding development in an c) Scarp slopes are dark – on the left or below area where the risk of mass movement was ridge lines; ✓ dip slopes are on the right or high; ✓stabilising slopes with nets or retaining above ridge lines. ✓ (2) walls ✓  (5×2) d) quartzite ✓ and shale/dolomite; ✓ [10] quartzite ✓ is the resistant layer (3) QUESTION 6 3. a) A lopolith is a saucer-shaped ✓ intrusion of 1 = elevation; ✓ 2 = slope; ✓ 3 = relief ✓ [3] massive igneous rock. ✓ A dyke is an upright wall-like ✓ intrusion of massive igneous QUESTION 7 rock. ✓ A lopolith is a horizontal ✓ intrusion, 1. butte ✓ while a dyke is a vertical ✓ intrusion. (6) 2. b) silica-rich = dyke, ✓ silica-poor = lopolith ✓ (2) crest [20] cliff / scarp / QUESTION 4 vertical slope free face 1. Dip slopes are on RHS, scarp slopes are on steep slope LHS. ✓✓ talus 2. 10–25º ✓ pediment 3. A huge igneous intrusion event – the Bushveld knickpoint Igneous Complex. The weight of the magma gentle slope pushed down on the sedimentary rock beneath it, making it crack and tilt; faulting ✓✓✓  ✓✓✓✓✓✓✓ 4. quartzite (metamorphic), shale (sedimentary), 3. dry/semi-arid ✓ [9] dolomite (sedimentary); quartzite is erosion resistant ✓✓✓✓ QUESTION 8 5. The dip slope is protected from erosion by the 1. A = rockfall; bedrock; it breaks away from steep resistant layer of rock that forms the ridge’s slope and bounces or showers down ✓✓ ‘backbone’. The scarp slope erodes at a constant B = mudslide; mud (silt or clay and water); it angle by the process of scarp retreat. ✓✓[12] flows fast with a cement-like consistency ✓✓ C = landslide; soil and rock/regolith; combination QUESTION 5 of slump (where material drops in one piece) and 1. landslide: sudden mass movement along a slippage flow ✓✓ plane/part slump, part debris flow/a general term D = soil fluction/solifluction; soil particles; for sudden mass movements ✓ creeping, flowing movement of individual mass movement: the movement of material particles that expand and contract as they freeze downslope under gravity ✓ and thaw ✓✓ 2. Rain soaks slope material with water. Water makes 2. D, C, B, A (it’s difficult to distinguish between B slope material heavier ✓ and lubricates it/reduces and C, so either one can come first) ✓✓ [10] friction. ✓ [Total: 118 marks] 6 S T U DY & M A S T E R S U P P O R T PA C K