metamorphism

Question 1

what is metamorphism?

Answer 1

iso chemical process by whihc rocks are changed by either tem, pressure or both.

Question 2

what happens to the comp of the new rock?

Answer 2

stays the same as the parent rock

Question 3

what can metamorphism result in

Answer 3

destruction of fossils/beds/sed. structures
hardening of the rock
change in colour
alignment of minerals
growth of new metamorphic minerals

Question 4

temp increses with…

Answer 4

DEPTH

Question 5

where do high temps occure

Answer 5

near igneous intrusions

Question 6

temp increases has what effect on rate of metamorphic reaction

Answer 6

rate of metamorhic reaction increases

Question 7

pressure increases with..

Answer 7

DEPTH

Question 8

term for no elements added or removed (exept water and CO2)

Answer 8

isochemical

Question 9

pressure exerted by fluids between grains in a pourous rock?

Answer 9

PORE PRESSURE

Question 10

pressure from weight of overlying rock bringing minerals togethers

Answer 10

LOAD PRESSURE

Question 11

pressure from folding or faulting (usually over a short period of time)

Answer 11

TECTONIC PRESSURE/STRESS

Question 12

why does metamprhic rate increase with tmep

Answer 12

many reactions need heat to take place

increases rate of ion diffusion between minerals

Question 13

which are more common? pressure or temp dependent reactions

Answer 13

temp dependent reactions

Question 14

how long do metamorphic reactions take

Answer 14

millions of years, temp and pressure conditions must remain over long periods of time for these reactions to take place

Question 15

three types of metamorphism

Answer 15

contact
burial
regional

Question 16

what is contact metamorphism

Answer 16

occurs adjacent to igneous intruisons
due to increase in temp of country rock
produces a metamorphic aureole
minerals not alligned due to low pressure

Question 17

temp of contact metamorphism

Answer 17

more than 200 (HIGH)

Question 18

pressure of contact metamorphism

Answer 18

LOW less than 200 MPa

Question 19

what is burial metamorphism

Answer 19

occurs under sediments also in subdiction zones

can overlap with diagenisis

Question 20

temp of burial metamorphism

Answer 20

less than 200 degrees (LOW)

Question 21

pressure of burial metamorphism

Answer 21

HIGH-MEDIUM 200-1000 MPa

Question 22

what is regional metamorphism

Answer 22

caused by collison of plates or subduction
large scale
alligned minerals due to pressure high
occure in cores of fold mountains

Question 23

temp of regional metamorhism

Answer 23

around 200-700 degrees (LOW-HIGH)

Question 24

pressure of regional metamorphism

Answer 24

LOW-HIGH 100-1000 MPa

Question 25

what is foliation

Answer 25

texture of meta. rocks, formed by the preffered alignment of flat platy minerals

Question 26

what is slaty cleavage

Answer 26

texture in fine grained rocks formed by low grade metamorphism. platy minerals re crysatlise perpendicular to the direction of stress applied during metamorphism so rock splits into sheets

Question 27

foliated rocks produced by metamorphsim

Answer 27

slate schist gneiss

Question 28

slate parent rock

Answer 28

shale

Question 29

slate colour

Answer 29

dark grey

Question 30

slate texture

Answer 30

slaty | fine

Question 31

slate composition

Answer 31

clay minerals | msucovite mica

Question 32

slate type and grade of metamorphism

Answer 32

low grade regional

Question 33

schist parent rock

Answer 33

shale

Question 34

schist colour

Answer 34

slivery green

Question 35

schist compostion

Answer 35

muscovite and biotite mica quartz garnet kyanite

Question 36

schist texture

Answer 36

shisosity | medium 1-5mm

Question 37

schist type /grade of metamo..

Answer 37

medium grade regional

Question 38

gniess parent rock

Answer 38

shale

Question 39

gniess colour

Answer 39

dark and light bands

Question 40

gniess texutre

Answer 40

gnuessose banding | coars >5mm

Question 41

gniess comp

Answer 41

biotite mica mafic minerals quartz

Question 42

gniess grade/type metamrphsim

Answer 42

high grade regional

Question 43

unfoliated rocks from metamprhsim

Answer 43

marble quartzite spotted rock

Question 44

marble PARENT ROCK

Answer 44

limestone

Question 45

marble COLOUR

Answer 45

white

Question 46

marble TEXTURE

Answer 46

granoblastic | medium grain 1-5mm

Question 47

marble COMP

Answer 47

calcite

Question 48

marble TYPE OF METAMORPHSIM

Answer 48

contact or regional

Question 49

quartzite PARENT ROCK

Answer 49

sandstone (composed of quartz)

Question 50

quartzite COLOUR

Answer 50

white/grey

Question 51

quartzite TECTURE

Answer 51

grano blastic | medium 1-5 mm

Question 52

quartzite COMP

Answer 52

quartz

Question 53

quartzite TYPE OF METAMORPHSIM

Answer 53

contact/regional

Question 54

spotted rock PARENT ROCK

Answer 54

slate or shale

Question 55

spotted rock COLOUR

Answer 55

dark with darker spots

Question 56

spotted rock TEXTURE

Answer 56

``` slaty cleavage (if slate is parent rock) fine ```

Question 57

spotted rock COMP

Answer 57

clay minerals | mica

Question 58

spotted rock TYPE OF METAMORPHSIM

Answer 58

contact

Question 59

what does granoblastic texure mean

Answer 59

meta rocks with equidiminsional interlocking crystals

Question 60

what is a polymorph

Answer 60

mineral that occurs in differnt crystal forms but has same compostion