8.2 Geological Structure and Landscape Flashcards
Which coastline is concordant and which coastline is discordant (2)
- Left is Concordant
- Right is Discordant
Example of Concordant coast (2)
- Lulworth, Dorset
- E.g. Lulworth Cove
Example of discordant coast (2)
- West Cork, Ireland
- E.g. Dunmanus Bay
Concordant Coasts (4)
- Also known as ‘___________’
- Generated when _________
- Run _________________
- E.g. __________________
- Also known as ‘Pacific Coasts’
- Generated when rock strata
- Run parallel to the coastline
- E.g. Lulworth in Dorset
Disconcordant Coasts (5)
- Also known as ‘____________’
- Created when __________
- ____________ at __________
- So ________________ the coastline
- E.g. ____________
- Also known as ‘Atlantic Coasts’
- Created when rock strata
- Intersect the coast at an angle
- So geology varies across the coastline
- E.g. West Cork. Ireland
Joints, Faults and Fissures & Erosion (4)
- Rocks with _______________________, like _____________
- Are _____________ to the processes of _______________
- As these processes _____________
- On the ______________ in the _________
- Rocks with the presence of more joints and faults, like sedimentary rocks
- Are more susceptible to the processes of erosion and weathering
- As these processes exert forces
- On the weaknesses found in the rock strata
Why discordant coastlines ‘smooth’ over time (6)
- The effect of _____________
- Concentrate ___________________, meaning __________
- Leads to the _____________________
- Like _____, _____, _____ and _______
And create __________________ in ______
- Meaning _______________
- The effect of wave refractions
- Concentrate powerful waves at headlands, meaning greater erosion
- Leads to the formation of headland features
- Like caves, arches, stacks and stumps.
- And create lower, diverging wave crests in bays
- Meaning reduced erosion
90: Discordant
Parallel: Concordant
Fissures (3)
- ___________in ______
- Often only __________________
- Which represent ___________________________
- Tiny cracks in rocks
- Often only a few cm or mm long
- Which represent weaknesses that erosion can exploit
Faults (2)
- ____________ in _____
- Produced by _____________
- Major fractures in rocks
- Produced by tectonic forces
Dalmation Coasts (4)
The angle the rock layer forms with the horizontal bedding plane is referred to as the dip. Rocks can dip either towards land or towards the sea.
Bedding planes that dip towards the sea create a gentler cliff profile. But these cliffs are vulnerable to mass movement processes, like rockfalls.
Bedding planes that dip towards land tend to create a steeper cliff profile. But these cliffs are more vulnerable to erosion processes, like hydraulic action and abrasion.
Examples of Concordant Coastlines (3)
- Haff coastlines, in the Baltic Sea
- Dalmatia, Croatia, in the Adriatic Sea
- Lulworth Cove, in Dorset
Examples of Concordant Coastlines
- Haff coastlines, in the Baltic Sea (5)
- Dalmatia, Croatia, in the Adriatic Sea
- Lulworth Cove, in Dorset
- Found on the Southern fringes of the Baltic Sea
- Long sediment ridges topped by sand dunes
- Run parallel to the coast just offshore
- Creating haffs/lagoons between the ridges and the shore
- E.g. Curonian Lagoon
Examples of Concordant Coastlines
- Haff coastlines, in the Baltic Sea
- Dalmatia, Croatia, in the Adriatic Sea (6)
- Lulworth Cove, in Dorset
- Drowned by sea level rise during the Holocene
- A concordant coastline of long, narrow islands
- Arranged in lines offshore
- Normally occur in high energy environments
- From where there is eustatic or isostatic change
- Creating a submerging coastline.
Examples of Concordant Coastlines
- Haff coastlines, in the Baltic Sea
- Dalmatia, Croatia, in the Adriatic Sea
- Lulworth Cove, in Dorset (3)
- The hard Portland limestone and fairly resistant Purbeck beds protect much softer rocks landward
- At Lulworth Cove, marine erosion has broken through the resistant beds and then reapidly eroded the wide coves behind
- At the back of these coves is resistant chalk,o which prevents erosion further island
