coasts Flashcards
what does the littoral zone consist of?
backshore,foreshore, nearshore and offshore
describe a rocky coast and a coastal plain
result from resistamt geology
-high relief
-withstand erosive forces
-often in high enegry env
result from a supply of sediment
-different terrestrial and offshore sources
-low relief
-low enegry env
sandy and eastury coast
igneous and examples
created by volcanic activity when magma or lava cools, forming crystals that are normally hard- granite and basalt
sedimentary and examples
formed by small particles that ahve been eroded, transported and deposited in layers (sandstone) or from remains of plants and animals (limestone and chalk)
metamorphic and examples
form from other rocks changing by extreme heat and pressure usually form from layers/bands of crystals and very hard. Shale can be compressed into SLATE and limestone can be transformed into MARBLE
what coastline does sedimentary rock have?
and landforms
- flat low lying relief
- low energy env
- beaches, spits and salt marshes, lagoons
low lying sandy beaches
what coastline does igneous rock have?
and landforms
rocky outcrops, resistant to ersion, high energy env
stack stump, wave cut platform
what is costal morphology
the shape and form of costal landscape and their feature.s
what is lithology
type of rock, sedimentary, metamprphic uncolidates, igenous…
what is geology
concordant dicordant coasts
joiting, dipping, faulting, folding ( e.g. these can form caves)
what is strata
layers of rock
what are bedding planes
(horizontal cracks) these are natural breaks in the strata,, caused by gaps during periods of rock formation
what are joints
(vertical cracks) these are features caused by either contraction as sediments dry out or by earth movements during uplift.
what are folds
formed by pressure during tectonic activity, which makes rocks buckle and crumple
what are faults
Faults are major fractures in rock created by tectonic forces
what’s a dip
this refers to the angle at which the strata lie (horizontally, vertically, dipping towards the sea or dipping inland)
what is the relief ( or height or slope of the land) affected by
geology and lithology
what are the 3 things that lithology includes
- rock type metamorphic sedimentary igneous
- how porous the rock is (permeability) linked to grain size and rock structure (crystal)
- vegetation
erosion rate of igneous rock?
1mm per year
erosion rate of sedimentary rock?
2.5cm per year
erosion rate of unconsolidated material?
1m per year
what’s a discordant coastline eg
where the geology alternates between more resistant bands of rock with less resistant bands, cut at right angles to the coast (perpendicular)
east facing dorset=isle of purbeck
headlands and bays
what’s a concordant coastline eg
where bands of more resistant and less resistant rock run parallel to the coast.
south facing dorset
a real life example of a concordant coast?
and explain formation process
litholgy, dip,small features, creates sea cave.
lulworth crumple is created by the collisiion of the african and eaurasion plates. pressure and cooling forms cracks in rocks. joints aer made as sedimentary rock is formed from pressure.micro geology forms points of weakness
dip- if rock layer dips towards the sea- blocks of rock to slide under the influence of gravity(Mass M) if dip landwards- weathering and erosion may attachk bedding planes- creating irregular profile.
cliffs may create protruisions(sticking out) and indentations, blowholes, geos
weka point(joint), weathered or eroded creating a sea cave.