Geomorphology

Question 1

what are bedding planes?

Answer 1

The planes separating each layer or strata. Horizontal layers of rock where sediments have been deposited

Question 2

how do horizontally-layered rocks erode?

Answer 2

The strata of these landscapes are uniformly resistant to erosion, which means: Each of the layers of rock erode at a similar rate.

Question 3

Briefly describe Hilly landscapes

refer to: climate, slopes. rock resistance, rainfall, temperatures, ARID regions.

Answer 3

Influenced by climate of region as well as the resistance of the rock

In hot and humid regions, slopes are gentle and rounded

High rainfall results in mass wasting and sheet erosion/ sheet wash

Key word: Sheet wash: Rainfall flowing over the land as a sheet

Higher temperatures encourage chemical weathering

This causes the soil layers to be thick and fine-grained

In ARID regions very little water is available, therefore very little chemical erosion occurs and THIN soil is found

Hills with narrow gullies and sharp ridges form in arid climates

Badlands are now evident

Slopes are steep and uneven

Question 4

what are badlands?

Answer 4

They are rugged, have steep slopes have have very little farming value

Question 5

What are Gullies?

Answer 5

small, narrow, long areas of erosion on a slope

Question 6

How are basaltic plateaus formed?

Answer 6

They built up over millions of years by lava repeatedly pouring through long narrow cracks in the ground.

The lava floods the landscape, building up to form deposits hundreds to thousands of meters thick.

Question 7

How do canyon landscapes develop?

refer to: erosion, running water, slopes

Answer 7

Develop where horizontal layers erode at different rates

Initially, the land is level, but running water soon finds weak places in the hard surface layer

Rivers erode vertically along cracks and joints and form deep, steep valleys

Valleys have steep sides

Question 8

Explain what Karoo landscapes consist of

Answer 8

Develop out of canyon landscapes.
Landscape consists of flat-topped mountains or hills of differing widths, with steep , concave shaped sides.

The plateau is protected by a resistant hard rock, (dolerite)

Caprock ( hard, resistant rock) is evident on the top of features (usually sandstone and dolerite sills)

Rivers find weaknesses and erode vertically

Question 9

What is dolerite?

Answer 9

Horizontal layer of igneous rock

Question 10

Describe the formation of Karoo landscapes

Answer 10

Floor of canyon gradually becomes wider, plateau surface gets narrower

Plateau remains as its original height (due to resistant caprock)

The eroded plateau develops into a series of ridges and mesas or table mountains

Mesas are further eroded to form BUTTES, POINTED-BUTTES and eventually CONICAL HILLS

Question 11

he valleys in a Karoo landscape WIDEN by means of ______

Answer 11

SCARP RETREAT or BACKWASTING

Question 12

What is scarp retreat caused by?

Answer 12

lateral erosion and weathering

Question 13

What does scarp retreat cause the formation of?

Answer 13

mesas, buttes, pointed buttes and conical hills

Question 14

What is a pediplain and how is it formed?

Answer 14

It is a Large, low-angled plain.

As the plateau surface narrows, canyon floors become wider, and a pediplain is formed.

Question 15

What are Mesas?

Answer 15

Flat-topped mountains with GREATER WIDTH than HEIGHT (Has caprock)

Question 16

What are buttes?

Answer 16

Flat-topped hills with with GREATER HEIGHT than WIDTH (has caprock)

Question 17

Define pointed-buttes

Answer 17

Narrow hills with a sharp peak at the top (has caprock)

Question 18

What are conical hills?

Answer 18

Small pointed hills (NO caprock)

Question 19

Define chemical weathering

Answer 19

Decomposition of rock due to chemical processes, often involving water, carbon dioxide and oxygen.

Question 20

Define mechanical weathering

Answer 20

the physical break-up of rocks, often due to extreme temperatures

Question 21

In humid climates, the slopes of hills are often suitable for FARMING and HUMAN SETTLEMENT.

Explain why the above statement is true.

Answer 21

Water causes the rock to decompose in a process called CHEMICAL WEATHERING resulting in thick, fine-grained soil layers forming gentle slopes

Farmers would use contour ploughing to grow crops

Question 22

In arid climates, the rugged, steep slopes of the ‘BADLANDS’ have little agricultural value. Explain why.

Answer 22

There is little water

Mechanical weathering results in thin coarse-grained soil layers

Question 23

An example of a basaltic plateau is the Drakensburg. state whether this area is suitable for human settlement and why.

Answer 23

Drakensburg is a great TOURIST ATTRACTION

Little value for human settlement and farming

High altitude results in cold temperatures

Slopes are also rugged and steep

Question 24

It is nearly impossible to settle on canyon landscapes. explain why and give a reason for people still going there.

Answer 24

Impressive scenery = great tourist attraction

Farming is impossible due to rugged, steep slopes, no access to irrigation

Settlement is very difficult and virtually impossible to implement infrastructure (electricity and water provision) or construct traffic routes

Question 25

Give a reason as to why it is difficult to farm on Karoo landscapes.

Answer 25

Farming can take place on the wider canyon floors and pediplains, but lack of rainfall is the issue