Desert LandformsYOU MUST… Describe the characteristics of the fluvial and aeolian landforms listed

YOU SHOULD… Explain the physical processes that created these landforms

YOU COULD… Support your knowledge of the above with specific facts and figures

What you need to knowLandforms resulting from wind action:• Yardangs• Zeugen• Sand dunes

Landforms resulting from water action:PedimentsInselbergsMesas and buttesSalt lakesAlluvial fansWadisBadlands

NB: Desert pavements, ventifacts, deflation hollows and rock pedestals are NOT mentioned by name in the spec, these can be used as supporting examples in essays but you cannot be asked a direct question on them.

What you need to know• Yardangs• Zeugen• Sand dunes• Pediments• Inselbergs• Mesas and buttes• Salt lakes• Alluvial fans• Wadis• Badlands

Just like with River landforms you must be able to:

- Draw a sketch of each one

- Describe what is looks like, giving specific facts and figures if you can

- Explain how it formed

Wind Action (aeolian landforms)• Yardangs• Zeugen• Sand dunes

Yardangs• Form where there are

vertical layers of hard and soft rock aligned to the direction of the prevailing wind.

• Practise drawing this sketch and use the information in your booklet to explain how they form.

• Also see the diagrams on p. 138 of your textbook.

Yardangs on Mars

Zeugen• Form where there

are horizontal layers of hard and soft rock.

• Practise drawing this sketch and use the information in your booklet to explain how they form.

• Also see the diagrams on p. 138 of your textbook.

Up to ____m per year

Steeper, slightly ____________ ______________ slope

The bottom of the slope contains ________ grained sand so it is more gentle. It may have ________ _____________

Sand is transported up the __________ windward slope by the processes of ___________________ and __________ _________

Prevailing wind _________________

Up to _______ m high

The _________ of the dune face downwind. They contain less sand so they are easier to move

Sand continually ____________ over the sharp crest

The top of the leeward slope is steep because it’s made of ___________ grained sand and it’s kept steep by wind ___________

direction concave 30 horns 30 leeward eddies fine coarse

saltation surface creep avalanches gentle sand ripples

Sand dunes• Make sure you know

about barchans dunes in detail

• Practise sketching and labelling this diagram

• You could mention one or two others e.g. star dunes

• Also see the diagrams on p. 139 of your textbook.

Water Action (fluvial landforms)• Pediments• Inselbergs• Mesas and buttes• Salt lakes• Alluvial fans• Wadis• Badlands

Pediments• Gently sloping

surface (between 2o and 7o) formed at the foot of a cliff.• Cut in solid rock or

covered with graded debris (finer material furthest away from cliff).

Mesas and Buttes• Isolated highlands left behind after the surrounding rock has been eroded away by water• Usually formed in flat-bedded (rock with horizontal layers) sedimentary rock or lava flows.

Valley cut by river

Butte

Resistant rock

Softer rock covered with scree

Mesa

Walt hiding his money

Scree slope

Inselbergs• Similar to Mesas and Buttes except

more rounded and smooth sided• Usually formed in unbedded

(uniform, without layers) igneous or metamorphic rocks• Can vary in size and shape, e.g.

Murphy’s Haystacks in Australia, which are around 8m high…

Uluru, Australia, 350m high

Wadis• A desert valley

that contains an ephemeral river• Can vary greatly

in size and shape• May be relict

landforms• Usually have a

lot of debris and thick sediment from flash floods

Wadi Rum, Jordan

Alien planet in movie Prometheus

Good. Only suggestion I might make is to make it narrower to allow you to show desert plateau on either side. Also label deposited debris/braiding on channel bed.

Alluvial Fans• Material is deposited in a

fan shape as a river leaves a highland area• Sediment is sorted in size

from largest to smallest• Several fans may coalesce

to form a bajada

Badlands• Arid or semi-arid

terrain with soft sedimentary rock that has been deeply eroded by rapid overland flow.• Contain landforms

such as wadis and alluvial fans• Thought to erode

about 1 inch per year

Desert Landforms Challenge!• Get into pairs• Around the room are places to draw each landform• You will have 1 minute on each landform• The first person must draw it, everyone else can add

labels/annotations or extra parts to the sketch