Metamorphic Rocks

Question 1

What are the three agents of metamorphism?

Answer 1

Heat, Pressure, chemically active fluids.

Question 2

What causes heat metamorphism?

Answer 2

geothermic gradient, magma, and friction

Question 3

What causes pressure metamorphism?

Answer 3

Depth, directed pressure,

Question 4

How do chemically active fluid metamorphose rock?

Answer 4

depth, hydrothermal fluids

Question 5

what 3 changes result from metamorphism

Answer 5

increased density, coarsening of crystals, foliation

Question 6

what is foliation?

Answer 6

alignment of platy or engate mineral grains

Question 7

what is rock cleavage?

Answer 7

how a rock breaks

Question 8

what is a protolith?

Answer 8

the stone before it was metamorphose.

Question 9

what are the two categories prior to naming?

Answer 9

foliated and nonfoliated

Question 10

shale, fine grained, dull luster

Answer 10

slate

Question 11

shale, fine grained, sheen, crenulations

Answer 11

phyllite

Question 12

shale, coarse grained, mica minerals

Answer 12

schist

Question 13

shale, coarse, felsic and mafic bands

Answer 13

gneiss

Question 14

granite, coarse, felsic and mafic bands

Answer 14

gneiss

Question 15

basalt, coarse, aligned black prisms

Answer 15

amphibolite

Question 16

conglomerate, flattened pebbles

Answer 16

metacongomerate

Question 17

limestone, coarse grained, calcite crystals

Answer 17

marble

Question 18

sandstone, coarse grained, quartz crystals

Answer 18

quartzite

Question 19

coal, “black gold”, gold sheen, very clean

Answer 19

anthracite

Question 20

steps in the formation of coal

Answer 20

1. accumulation of organic remains in tropical swamp environment
2. organic material forms peat
3. organic material forms lignite
4. organics further concentrated to form bituminous coal
5. heat and pressure form antracite

Question 21

ultramafic, green, glossy sheen

Answer 21

serpentinite

Question 22

ultramafic, soapy feel, talc dominates

Answer 22

soapstone

Question 23

any, spotted, from contact metamorphism

Answer 23

hornfels

Question 24

what are index minerals

Answer 24

metamorphic minerals that indicate the temperature associated with metamorphic alteration

Question 25

low grade temperature and index mineral

Answer 25

200 C chlorite

Question 26

intermediate temperature and index mineral

Answer 26

500 C garnet

Question 27

high temperature and index mineral

Answer 27

800 C silimanite