Physiographic Regions Of Australia

Front 1

General characteristics of the Great Western Plateau

Back 1

- ancient plateau, old erosional surface.
- average height of 500m above sea level, 1200m in some places e.g. Darling Scarp
- land surface is low, flat and monotonous
- mostly sedimentary rock but granite, gneiss and monogneeks are exposed in places such as the Darling Scarp
- some uplifted areas e.g. Flinders Ranges, Mt Lofty Ranges, Macdonell Ranges.

Front 2

Account for the general characteristics of the Great Western Plateau

Back 2

- general flatness is attributed to the lack of tectonic activity in recent years.
- originally formed due to tectonic forces uplifting the land
- Stirling Ranges created by folding followed by faulting.
- Hamersley and Chichester Range create a horst and graben with Fortescue river, formed by folding.
- Erosional and depositional forces now act on the plateau
- wind erosion in stony deserts
- deposition creates sandy deserts
- water erosion creates canyons and gorges e.g. Weano, Hancock and Joffre Gorges form canyons and waterfalls as water has cut through the layers of ironstone, dolomite and shale.

Front 3

Drainage patterns of the Great Western Plateau
(not in the syllabus)

Back 3

- 2 distinct drainage systems: the south west corner and the north east sections.
- mostly external drainage (rivers flow into oceans)
- in the south west corner the Swan and Avon rivers flow west into the Indian Ocean.
- in the north east sections the Ord and Fitzroy rivers flow into the Timor Sea.
- ancient internal drainage features flow inland into salt lakes but are only active if cyclones cause flooding which reaches inland areas e.g. Lake Disappointment.

Front 4

General characteristics of the Eastern Highlands

Back 4

- continuous series of elevated tablelands.
- 4 main regions: Atherton tablelands, Australian alps, New England tableland and the Tasmanian highlands.
- separated by deep valleys with steep cliff faces.
- extend from Cape York in the North to Tasmania in the South.
- up to 2000m above sea level in some places.
- Blue Mountains 1200m, Australian Alps up to 2000m, Mt Kosicuzko highest point in Aus is 2228m.
- mainly block mountains created but faulting.
- some fold mountains and evidence of volcanic activity e.g. Glasshouse Mountain QLD.

Front 5

Account for the characteristics of the Eastern Highlands.

Back 5

- General formation: folding of ocean sediments followed by faulting.
- Kosciusko Uplift, upfolded and downwarped rocks of a sedimentary basin.
- Fold mountains and horsts were thrust up in a line that forms the eastern edge of the continent.
- volcanic activity created some peaks and plains -> erosion exposed volcanic plugs.
- entire region was once part of a soft sedimentary basin which was tectonically lifted as the Australian and Pacific plates were pushed together.
- gradational and erosional forces especially rivers now create valleys down tablelands.

Front 6

Drainage of the Eastern Highlands
(not in the syllabus)

Back 6

- both external and internal drainage.
- flow from Highlands, east into the Pacific Ocean e.g. Hawkesbury River
- short and fast river flow from highlands into ocean and move sediment easily
- north to south - long slow rivers e.g. from highlands to southern ocean near Adelaide, the Murray/ Darling river.
- internal rivers flow from highlands to central lowlands e.g. Murrumbidgee river flows into Murray-Darling.

Front 7

Describe the general characteristics of the Central Lowlands.

Back 7

- consists of a large basin and sedimentary rocks
- 3 basins Carpentaria Lowlands (northernmost), Lake Eyre Basin (middle) and Murray Darling basin (southern).
- areas dips down from Eastern Highlands (geosyncline) as a result of tectonic movement.
- low lying, 200m asl average, goes below sea level in some places.
- stretches from the Gulf of Carpentaria (North) to the Southern Ocean near Coorong in South Australia.

Front 8

Account for the characteristics of the Central Lowlands

Back 8

- transportation and deposition of alluvial sediments eroded and transported from highlands by ancient and existing rivers.
- Lake Eyre Basin formed 60 million years ago when South Australia began to sink below sea level.
- once covered by an inland sea but escape the influence of the underlying plate and the shallow seas drained.

Front 9

Drainage of the Central Lowlands
(not in the syllabus)

Back 9

- Carpentaria Basin contains numerour meandering rivers fed by summer monsoons.
- rivers in CL flow north e.g. Flinders, Gilbert and Mitchell rivers.
- Lake Eyre Basin is an internal drainage system.
- run-off from Eastern Highlands, CL is directed into Lake Eyre.
- Dry salt lakes are inundated with water every few decades.
Part of the groundwater system called the Great Artesian Basin.
- Murray-Darling Basin is Australia's largest external drainage system.
- approx. annual discharge 15 million megalitres.
- Murray, Darling and Murrumbidgee tributaries dominate all eventually join to form Murray river.
- long, slow rivers flow south out of Victor Harbor into Southern Ocean.

Front 10

Describe the general characteristics of the Coastal Lowlands

Back 10

- low lying, between 0 and 200m above sea level.
- situated between the shoreline and inland high country.
- narrow, flat and fringe most of the continent.
- width is between one and 200 km
- Western coastal lowlands are a relatively continuous zone stretching from Canning Basin to Esperance.
- Eastern Coastal lowlands are a discontinuous and complex system of flood plains.
- Stretch from Cape York Peninsula, along the east coast and west to the South Australian border.

Front 11

Account for the characteristics of the Coastal Lowlands.

Back 11

- waves deposited sand
- rivers deposited sediment at their mouths.