What is the difference between a concordant and discordant coast?
What is the difference between a concordant and discordant coast?
Coastlines where the geology alternates between strata (or bands) of hard rock and soft rock are called discordant coastlines. A concordant coastline has the same type of rock along its length. Concordant coastlines tend to have fewer bays and headlands.
What is the geological structure of concordant and discordant coastlines?
Concordant and discordant coasts— Concordant coasts are made up of the same rock type, parallel to the sea. On discordant coasts have alternating rock types perpendicular to the sea forming headlands and bays. Coastal retreat—when coasts move further in land as cliffs collapse into the sea due to erosion.
Are bays concordant or discordant?
The most common way we see headlands and bays is on a discordant coastline, where the rocks are distributed alternate resistant and then less resistant rock as if in a stripy pattern with the bands of rock pointing towards the see rather than flat up against it (this is known as concordant).
How is a discordant coastline formed?
A discordant coastline occurs where bands of different rock type run perpendicular to the coast. The differing resistance to erosion leads to the formation of headlands and bays. The Portland limestone is resistant to erosion; then to the north there is a bay at Swanage where the rock type is a softer greensand.
What is the difference between concordant and discordant plutonic bodies?
The pre- existing rocks can be igneous, sedimentary or metamorphic. If the country rock be made up of sedimentary bedding, a concordant intrusive mass should run parallel to the bedding planes while a discordant body must cut across them.
Where is a discordant coastline?
Discordant These are where rock strata or structures are aligned at an angle to the coastline. Discordant coasts have a crenellated pattern of projecting headlands and indented bays. Discordant coasts are also known as Atlantic coasts, after the Cork coastline in the Republic of Ireland.
What is a concordant coastline geography?
In coastal geography, a concordant, longitudinal, or Pacific type coastline occurs where beds, or layers, of differing rock types are folded into ridges that run parallel to the coast.
What is the difference between concordance and discordance?
Concordance, as used in genetics, usually means the presence of the same trait in both members of a pair of twins. Discordance, in genetics typically means that a similar trait is not shared between twin members.
What is the difference between a concordant body and a discordant body?
A discordant igneous rock body cuts across the pre-exiting rock bed. Batholiths and dikes are examples of discordant rock bodies. A concordant igneous rock body runs parallel to the pre-existing bedrock.
What do you understand by concordant bodies and discordant bodies?
DISCORDANT A discordant igneous rock body cuts across the pre-exiting rock bed. A dike is an example of discordant rock bodies. 2. CONCORDANT A concordant igneous rock body runs parallel to the pre-existing bedrock. Laccoliths and sills are examples of concordant igneous rock bodies.
What’s the difference between discordant and concordant coasts?
Concordant coasts are also known as dalmatian coasts, after the Dalmatian region of Croatia, or Pacific coasts, after the coastline of Chile in South America. Discordant These are where rock strata or structures are aligned at an angle to the coastline. Discordant coasts have a crenellated pattern of projecting headlands and indented bays.
Where are the Concordant bands on the coast?
In places such as Worbarrow Bay and St Oswald’s Bay, lateral widening of coves led to them joining into a single bay, with remnants of the outer Portland left as a line of stumps parallel to the coast, e.g. Bull’s Head in St Oswald’s Bay. Straight coastline now formed by a concordant band of constant chalk.
Where does the concordant coastline start and end?
The concordant coastline runs from west to east along the south coast. The discordant coastline runs from Studland Bay to Durlston Head as the geology changes from clay and sands, to chalk, to clay and sands again to limestone. A wave-cut platform is formed when: • The sea attacks a weakness in the base of the cliff.
Where is the discordant coastline in South Australia?
The concordant coastline runs from west to east along the south coast. The discordant coastline runs from Studland Bay to Durlston Head as the geology changes from clay and sands, to chalk, to clay and sands again to limestone. Discordant and concordant coasts
