Costal/river Landforms Flashcards
What does a discordant cost line mean
Alternative bands of soft and hard rick
What does a concordant costline mean
Alternative layers of soft and hard rock
How are head lands and bays formed
Soft rock eroded back to make bay while either side hark rock not eroded makes headland
What type of coastline for headlands and bays
Discordant
How are caves formed
From a head land with cracks cracks hydraulic action and abrasion opens crack to form cave
How is a arch formed
From cave repeated erosion deepens cave until arch is formed
How is a stack and stump created
Erosion continues on rock supporting arch. Arch collapses leaving stack. Stack waves erode stack collapsing to stump
How is a wave cut platform formed
From cliff erosion where cliff meets water creating wave cut notch unstable rock above collapses cliff retreated process repeats
What process forms beaches
Deposition
Where are beaches found
Between high and low water marks
What wave forms beaches
Constructive
How are sand beaches created
Weak back was pushed sand back but doesn’t take it with the wave long slop created
How are shingles beaches created
Waves take sand but not enough energy to take shingle
How are spits created
Long shore drift transports sand shingle past bend deposits it was in sea
Wind curves the deposited material. Material accumulates
How are bars created
Spit and headland join cutting off sea lagoon formed friction causes waves to slow and deposit next to spit
How are sand dunes formed
Sand deposited by long shore drift moves up by wind obstacles slow wind creating little dunes. Colonised by plants stabilising it more sand deposited creating foredunes with embryo dunes infront
How are waterfalls formed
Discordant rocks
Soft rock erodes (step in river)
Steep drop made
Under cut bellow hard rock
Hard rock collapses swirls round (plunge pool)
Overtime more collapsing gorge formed
How are meanders formed
Current faster on outside (erosion)
Slower on inside material deposited making bend
How are oxbow lakes created
Starts Meander
Erosion caused land between bends(neck) to get smaller
River breaks through neck
Leaves meander behind deposition cuts on where meander was leaving water filled lake
