Landscape

Question 1

Composition of continental crust and ocean floor

Answer 1

Continental crust
- upper zone of felsic material, High in Si, granite, lower density
- lower zone of magic material- high in Fe, Mg, basalt, Gabbro, high density
Ocean floor
- entirely composed of basalt lava flows (magic)

Question 2

What is Rifting and examples of it

Answer 2

Rifting is the stretching of continental land mass, forming a rift valley and can cause volcanic activity
An example of this is the east african rift - rifting african/ arabian plates - expanding red sea, gulf of Aden, rift valley
Another example is the east coast of australia 96-50 My BP
The ocean moves into widening gap and basaltic lava forms sea flood

Question 3

Position of Australia since at least the cambiran

Answer 3

Area had been below the sea since at least the cambiran (570My)- rifting caused the ocean to widen
Current effects- large amount of salt water in Australian Soils

Question 4

Difference between stratovolcano and shield volcano

Answer 4

Stratovolcano
- production of gas and explosive eruptions, e.g. Indonesia
Shield volcano

Question 5

Australian hot spot volcanos

Answer 5

Basalt floow
- general age trend- older in north younger in south
- high fertility soils relatively young, high nutrient status, good physical char
eg- Mt Warming- local hot spot volcano and has eroded since 23 million years ago

Question 6

What are chemical deposition landscapes

Answer 6

Movement of iron 9silica_ in groundwater
Evaporation causes precipitation
Cementation
erosion resistance
landscape inversion

Question 7

4 erosional processes

Answer 7

Mass wasting- soil creep, land slip, earthflows, landslides
Water- dissolution, fluvial proesses
Ice- glaciation
Wind

Question 8

What is soil creep and what are its impacts

What is landslip and what are its impacts

Answer 8

Soil creep is the slow downward progression of rock and soil down a low grade slope as a result of prolonged stress and pressure
Australian soil is old–> as a result creeps

Slow downhill movement

• occurs when soil is wet
• human induced// accelerated

Question 9

Explain process of dissolution

Answer 9

soluble rocks dominate
dissolution by ocean- cliffs
dissolution nullarbor, sink holes, karst

Question 10

What are fluvial landscapes

Answer 10

processes associated with rivers and streams and the deposits and landforms created by them

Question 11

Different stages of fluvial landscapes (graded landscape_

Answer 11

recent uplift (waterfalls)
Stream development (gradient evening out)
Graded stream profile (floodplain developing)
Flood plain development (meanders forming)

• increasingly graded stream

Question 12

Landscape evolution

Answer 12

recent tectonic landscape-> mature streams-> peneplain
mountainous–> flat

Peneplain-> base level changes-> landscape rejuvenation
flat–> mountanous plateau

Question 13

Describe what Australia was like during the glacial period and what evidence is there for this?

Answer 13

Ice age- 300myr
Australia was twice as dry and twice as windy, the shoreline was much lower
Evidence- wind erosion- ice age dune fields- low rainfall areas, management effects

Question 14

What are the two types of weathering processes

Answer 14

Physical weathering- fracturing or breaking of rocks

Chemical weathering- oxidation, hydrolysis, dissolution

Question 15

Examples of physical weathering

Answer 15

Frost weathering
- water expansion, cold environment, freeze/ thaw, talus slope
Salt crystal growth
- arid environments, wetting + drying, salt accumulation at surface
Exfoliation
-insolation + salt

Primary materials of weathering are quart, feldspar and biotite/ amphibole

Question 16

Examples of chemical weathering

Answer 16

Primary materials
- formed under high pressures and temperatures 
-hydolysis- reaction with water
- oxidation- reaction with oxygen 
Chronic acid dissolution

Question 17

What are the four layers of the soil and what do they contain

Answer 17

O horizon- organic layer (leaf litter)
A horizon- top soil
B horizon- sub soil
C horizon- parent material

Question 18

Soil formation of basalt and granite

Answer 18

Basalt
Poor drainage, silica content remains high, limited oxidation
low lying position, lower temperature, low rainfall, medium time frame
Granite
arid environments limited leaching, high base status, long time frame

Question 19

What are the ideal conditions for soil and plant growth

Answer 19

• Support, water, aeration for roots, nutrients
  air-25%
  Water-25%
  Solid- 50%

Question 20

Where is basalt and granite found in australia?

Answer 20

basalt
darlingg downs
- fertile soil, vert heavy, high nutrient problems, virtuoso
toowoomba
- fertile soil, good physical character, moderate nutrients

Granite
heath lands
- infertile soil
-high acidity (problems)
-low nutrient storage 

Western downs

• moderate fertility soil
• can be high sodium
• lack of rainfall