Geography 4.3 - Geological Structure Flashcards
What is the rock type like on a concordant coastline?
Clays and sands
What features are found on a concordant coastline?
Concordant coastlines tend to have fewer bays and headlands.
A concordant coastline has the same type of rock along its length
What is the rock type like on a discordant coast
Limestone (hard)
Chalk (hard)
Clay and sands (soft)
What features are found on a discordant coast
Coastlines where the geology alternates between strata (or bands) of hard rock and soft rock are called discordant coastlines.
What are joints and faults?
A joint is a break (fracture) of natural origin in the continuity of either a layer or body of rock that lacks any visible or measurable movement
A fault is a crack in the Earth’s crust. Typically, faults are associated with, or form, the boundaries between Earth’s tectonic plates
Three factors of waves
First, the wind speed must be blowing faster than the transfer of energy from wave crest to wave crest. The second factor is the amount of time the wind blows, or wind duration. The third factor is the fetch, the uninterrupted distance over the sea for which the wind blows without a change in direction
How are spits formed
spit is an extended stretch of beach material that projects out to sea and is joined to the mainland at one end. Spits are formed where the prevailing wind blows at an angle to the coastline, resulting in longshore drift
Explain how beaches form
Beaches are the result of wave action by which waves or currents move sand or other loose sediments of which the beach is made as these particles are held in suspension
What is a bar
A bar is very similar to a spit. It is a ridge of sand or shingle which forms across the mouth of a river, the entrance to a bay or harbour. It is usually parallel to the coast.
What is the difference between a spit and a bar
Both of these landforms are the result of longshore drift and deposition of material by the sea so there is a definite similarity in the processes of their formation and development. Spits and bars are long, narrow accumulations of sand and/or shingle. … A bar starts in a similar way, and to begin with, is a spit