folding and faulting

Question 1

define folding

Answer 1

some rokc nuckle into folds when compressed
varies in scale from small ripples to folds that are many km

Question 2

symmetrical

Answer 2

result of equal compressional forces on both sides

Question 3

asymmetrical

Answer 3

compressional force on one side greater than on the other resulting in one limb steeper

Question 4

overfold

Answer 4

compressional force on one side so great both limbs face the same direction

Question 5

recumbent

Answer 5

one limb has been pushed over other limb causing axis of fold to become almost horizontal

Question 6

overthrust

Answer 6

compressional force on one side so great causes fold to fracture

Question 7

nappe fold

Answer 7

formed after overthrust fold breaking off along fracture line

Question 8

define fault

Answer 8

crack or fracture in earths crust along which thereis movement or displacement of rocks on either side of crack or fracture
when there is no movement called joints

Question 9

where do faults occur

Answer 9

occurs in areas where rocks undergo great stresses and areas deep below earths surface and common along transform plate boundary

Question 10

what does faulting lead to

Answer 10

displacement of rock whether horizontally or vertically

Question 11

define vertical displacement

Answer 11

new difference in height caused by faulting called throw

Question 12

define horizontal/lateral displacement

Answer 12

heave

Question 13

define fault plane

Answer 13

surface where rocks have been displaced

Question 14

define normal faults

Answer 14

tensional forces pull rock strata apart and result in normal faults in one block being pulled down called downthrow
long steep slope called escarpment or fault scarp can be formed along fault line
may be both vertical and lateral displacement
common along divergent plate boundaries

Question 15

define reverse faults

Answer 15

compressional faults push rock strata together forcing one side block to be pushed upwards called upthrow and this forms overhanging escarpment
vertical displacement

Question 16

transform strike slip fault

Answer 16

rocks pushed past each other in a horizontal direction resulting in horizontal displacement
here rock strata slide past each other along fault line

Question 17

define rift valley

Answer 17

another land form typically associated with faults
elongated deep area of subsidence or flat low lying valley formed between two block mountains also known as horst with steep fault scarps as its walls
usually between 30 to 60 km wide
also known as graben