how geological structures influence coastal landscapes

Question 1

what are strata

Answer 1

-the different layers of rock within an area and how they relate to each other
-collective term for multiple layers of rock

Question 2

what is deformation

Answer 2

-the dregree to which rock units have been deformed (titled or folded) by tectonic activity

Question 3

what is faulting

Answer 3

-the presence of major fractures that have moved rocks from their origional positions, displacing them either side of the fault line
-scusceptable to weathering/marine erosion depeding on where it is on the cliff

Question 4

what is the lithology of a rock

Answer 4

-a physical and chemical composition of the rock and its texture

Question 5

what is the geological structure of a rock

Answer 5

-the arrangement of rocks with features such as bedding planes, faults, folds, joint pattern and angle of dip

Question 6

what does the geological structure of a rock influence

Answer 6

-the resistance to erosion, morphology, development of cliff profiles and microfeatures

Question 7

what is the morphology of a rock

Answer 7

the shape

Question 8

what processes do lithology and structure of a rock combine with to create different coastal landscapes

Answer 8

-wave energy
-tides
-weathering
-erosion processes

Question 9

2 main influences to cliff profiles

Answer 9

-resistance to erosion of the rock
-dip of rock strata in relation to the coastline

Question 10

what is the dip of rock

Answer 10

-the angle of rock strata in relation to the horizontal
(angle of dip, can be inwards/outwards)

Question 11

what causes rock to tilt, causing dips

Answer 11

-sedimentary rock formed in horizontal layers
-titled by plate tectonic forces

Question 12

how is dip important in shaping the cliff profile

Answer 12

-tectonic movements can tilt rock, exposing weaker sedimentary layers to swift erosion

Question 13

features of horizontal dip

Answer 13

-vertical or near vertical profile
-notches reflecting strata that are more easily eroded

Question 14

features of seaward dip, high angle

Answer 14

-sloping, low angle profile
-one rock layer facing the sea
-vulnerable to rock slides down the dip slope

Question 15

features of seaward dip, low angle

Answer 15

-profile may exceed 90degrees inwards
-producing areas of overhanging rock
-very vulnerable to rock falls

Question 16

landward dips

Answer 16

-steep profiles of 70-80 degrees -very stable cliff with reduced rock falls

Question 17

whats a joint

Answer 17

-vertical cracks in rocks
-divide strata into blocks with a regular shape
-more joints is more weaknesses

Question 18

whats a fisure

Answer 18

-much smaller cracks in rocks
-can be a few cm or mm long
-weaknesses that erosion can exploit

Question 19

whats a bedding plane

Answer 19

-horizontal cracks in rocks
-lines that separate individual strata
-represent a change in depositional conditions during rock formation

Question 20

what causes layers of rock to buckle and crumple

Answer 20

folding
-due to pressure during tectonic activity

Question 21

what are the parts of a fold called

Answer 21

-the fold up part is called anticline
-the bottom downwards part of fold is called syncline