Folding

Question 1

how does folding occur?

Answer 1

two plates collide and land is compressed to form anticlines,limbs and cynclines.

Question 2

what are 5 types of folds?

Answer 2

1.Symmetrical Fold
2.Asymmetrical Fold
3.Overfold
4.Overthrust Fold
5.Recumbent Fold

Question 3

what happens when the two plates collide?

Answer 3

tension,. stress and pressure contributes to compression which creates the anticlines and synclines

Question 4

what was the caledonian orogeny?

Answer 4

it happened 400 million years ago.
american and eurasian plates collided.
formed the wicklow mtns.
mountains are old and low due to erosion and weathering.

Question 5

what was the amorican orogeny?

Answer 5

it happened 250 million years ago.
munster ridge and valley was formed.
when plates collided, softer rock such as chalk was totally removed by the effects of denudation.

Question 6

what was the alpine orogeny?

Answer 6

it happened 30 million years ago.
formed the alps.
highest peaks since its been so recent

Question 7

what is shearing?

Answer 7

when rock is moved sideways in opposite directions, it results in shearing and faulting in the rock

Question 8

explain how munster ridge and calley was a product of folding

Answer 8

380 million years ago, ireland was a hot, red sandstone desert.
350 million years ago, limestone developed on top.
when the two plates collided, rock strata was folded into anticlines and synclines
softer rock such as chalk was removed by denudation.
limestone remained in the synclines(valley floors) where rock layers are more protected.
River brandon

Question 9

what are constructive boundaries also known as?

Answer 9

Convergent Plate boundaries

Question 10

what happens in process of destructive/convergent boundaries?

Answer 10

oceanic plate is subducted underneath continental.
both plates are controlled by thermal convection currents in the mantle the convection currents flow towards each other.

Question 11

describe the oceanic plate

Answer 11

thinner but more dense.
silica and magnesium content.
plate is subducted underneath continental plate.

Question 12

describe continental plate

Answer 12

thicker but less dense.
silica and aluminum content.
this plate subducts the oceanic plate

Question 13

what happens to the oceanic plate after being subducted?

Answer 13

the subducted crust is melted into magma and recycled.

Question 14

what lanform can form at destructive plate boundaries?

Answer 14

Volcanic arcs such as the Andes mountains in south america.

Question 15

what are constructive plate boundaries also known as?

Answer 15

divergent plate boundaries

Question 16

how are the plates moved

Answer 16

plates move apart from one another due to thermal convection currents

Question 17

what happens as the plates seperate?

Answer 17

magma rises from the mantle to fill the gap, creating new crust

Question 18

what is often formed at these boundaries?

Answer 18

mid-ocean ridge

Question 19

how fast is the movement of the plates

Answer 19

typically slow, only moving a few centmetres a year