Erosional landforms Flashcards
What are bays and headlands?
Bays are recessed curved areas of water surrounded by land; headlands are coastal projections of land extending out to sea.
Formed due to different lithology of rocks at a discordant coastline with alternating bands of resistant and less resistant rocks causing differential erosion.
What geological factors contribute to the formation of bays and headlands?
Geology is the primary factor; erosional processes also play a key role.
Headlands are typically harder rocks like granite and limestone, while bays are usually softer rocks like clay.
What is the role of wave action in the formation of bays?
Constant wave action erodes softer rocks, leading to the formation of bays.
The orthogonal of waves directs to uneroded parts, enhancing erosion.
What is an example of a discordant coastline?
Isle of Purbeck in Dorset.
Hard rock is limestone; soft rock is clay.
What is a concordant coastline?
A coastline where the rock layers run parallel to the shore.
An example is Lulworth Cove.
How do cliffs form?
Cliffs are formed through geological processes from waves and wind attacking the base of a rock, leading to a vertical drop.
This process involves erosion.
What are wave cut platforms?
Flat, rocky surfaces created through erosion and deposition, found on or near shorelines.
Formed by destructive waves creating a wave cut notch.
What is the typical angle of a shore platform?
0 to 3 degrees.
The steepness depends on the strata of the regolith.
What are geos?
Steep narrow inlets in the rock of a coastline formed by wave attacks on faults or joints.
An example is Huntsman’s Leap.
What geological process leads to the formation of a geo?
Wave attacks on faults or joints in the rock.
This process can involve biological weathering and mass movement.
What are blowholes?
Similar to geos but do not develop the finger-like inlet due to wave action not attacking the base of the cliff.
Severe destructive waves can force water to spray out of the blowhole.
How do stumps form?
Stumps form from wave action identifying weaknesses in the rock, leading to erosion and weathering.
Example: Old Harrys Rock in Dorset.
What factors affect the rate of erosion of stumps?
The lithology of the rock affects erosion rate.
Harder rocks like chalk take longer to erode due to strong chemical bonding.
What is the role of hydraulic action in coastal erosion?
Hydraulic action contributes to the widening of faults or joints in the rock.
It is one of the erosional processes involved in the formation of coastal features.
What is the significance of orthogonal waves in coastal processes?
Orthogonal waves concentrate energy on headlands, enhancing erosion.
This process contributes to the formation of caves and stacks.
Fill in the blank: The average temperature affecting chemical weathering is _______.
21 degrees.
This temperature increases susceptibility to salt crystallization.
What are the key points in the summary of erosional processes?
Orthogonal, hard rock, headland, erosional processes, sub aerial processes, temporal.
This includes biological and chemical weathering dynamics.
