-
how does metamorphic rock form?
crust is exposed to rising pressure and temp
-
what are metamorphic rocks composed of?
sedimentary, igneous or metamorphic minerals that have been crystalized
-
what is metamorphism?
- caused by heat and pressure
- tectonic processes create regions of high heat flow and high pressure
-
about how much does the heat along geothermal gradient increase?
30 degrees
-
at temperatures between 150 and 250, clay minerals become _____ and ________
unstable, crystalize
-
in addition to heat and pressure what do chemically active fluids do?
transport heat and promote crystalization
-
as you increase the temp and pressure the grade of metamorphic rock increases (T/F)
T
-
what are the order of the metamorphic rocks as your increase the grade?
chlorite->muscovite->biotite->garnet->kyanite->sillimanite
-
_______ is a parent rock
shale
-
what is foliated texture?
produced by directed stress related to raginal metamorphism
-
slate
fracture along parallel lines
-
what is parallel mineral arrangement?
phyllite
-
what is parallel to sub parallel arrangement?
schist
-
gneiss
mineral seggregated into bands
-
what are the foliated metamorphic rocks?
- slate
- phyllite
- schidt
- gneiss
-
describe slate metamorphic rocks
- fine grained, mineral not visible
- clay mineral, chlorite
- dense
-
describe phyllite metamorphic rock
satiny luster
-
describe schist metamorphic rock
- medium to coarse grained, minerals visible
- muscovite, biotite, garnet, kyanite and others
- shiny luster
-
describe gneiss metamorphic rocks
- feldspars, quartz, muscovite, biotite, ferromagnesian minerals
- banded
-
directed stress in regional metamorphism causes______
foliation
-
what are the non foliated metamorphic rocks?
- marble
- quartzite
- metaconglomerate
- hornfels
- anthracite
-
when do non foliated rocks develop?
regional or contact metamorphism
-
explain marble metamorphic rock
- medium to coarse grained, mineral visible
- calcite
- hardnes 3
-
explain quartzite metamorphic rock
- quartz
- hardness 7; breaks across grains
-
explain metaconglomerate metamorphic rock
breaks across and around grains
-
explain hornfels metamorphic rock
- fine grained, mineral not visible
- clay mineral, muscovite
- dense, dark colored
-
explain antharacite coal metamorphic rock
-
the relationship between mineral assemblage and metamorphic grade is expressed by ____________
matamorphic facies
-
what is lithostatic stress
equal pressure from all directions
-
|
|