Intro/Metamorphism

Question 1

The process of change or transformation of a pre-existing rock, in the solid state, into another rock due to heat, pressure and chemically active fluids

Answer 1

Metamorphism

Question 2

A form of metamorphism due to hydrothermal fluids exchanging constituents with an external source.

Answer 2

Metasomatism

Question 3

What are the different kinds of metamorphism

Answer 3

1. Prograde Metamorphism
2. Retrograde Metamorphism
3. Local Metamorphism
4. Regional Metamorphism

Question 4

A kind of metamorphism where there is an increase in heat and pressure.

Answer 4

Prograde Metamorphism

Question 5

A kind of metamorphism where there is a decrease in heat and pressure.

Answer 5

Retrograde Metamorphism

Question 6

A kind of metamorphism that affects areas with less than 100 km².

Answer 6

Local Metamorphism

Question 7

A kind of metamorphism that affects areas greater than 100 km² and is commonly associated with convergent and divergent plate boundaries.

Answer 7

Regional Metamorphism

Question 8

Also known as “Protoliths,” are the original rocks from where the produced metamorphic rocks transformed from.

Answer 8

Parent Rock

Question 9

Enumerate the agents of metamorphism

Answer 9

1. Heat
2. Pressure
3. Chemically active fluids

Question 10

An agent of metamorphism that provides energy for chemical reactions and recrystallization of minerals.

Answer 10

Heat

Question 11

An agent of metamorphism that provides stress in equal directions or varying amounts in different directions.

Answer 11

Pressure

Question 12

An agent of metamorphism that provides and enhances mobility of ions present.

Answer 12

Chemically active fluids

Question 13

What are the two kinds of pressure?

Answer 13

1. Hydrostatic pressure
2. Lithostatic pressure

Question 14

A type of pressure that is also called confining pressure, is a uniform or isotropic form of pressure, where pressure is equal in all directions, which usually produces equant grains and non-foliated texture of metamorphic rocks.

Answer 14

Hydrostatic pressure

Question 15

A type of pressure also called burying pressure is a non-uniform or anisotropic form of pressure, where pressure is unequal in all directions, which usually produces inequant grains and foliated texture of metamorphic rocks.

Answer 15

Lithostatic pressure

Question 16

What are the different types of metamorphism?

Answer 16

1. Contact Metamorphism
2. Hydrothermal Metamorphism
3. Dynamothermal Metamorphism
4. Burial Metamorphism
5. Impact Metamorphism
6. Dynamic Metamorphism

Question 17

A type of metamorphism
-A variable pressure temperature, low metamorphism that develops locally where hot magma intrudes relatively cold, upper crustal country rock.
-What are the products of this metamorphism?

Answer 17

Contact Metamorphism
-Hornfels, metaquartzite, skarn

Question 18

-A type of metamorphism that results from chemical alteration from circulating fluids within cracks and fissures. Pervasive at ocean-spreading ridges that experience tension, thinning and uplift, causes metasomatism.
-What are the products of this type of metamorphism?

Answer 18

Hydrothermal Metamorphism
-Alteration products, metallic ore deposits

Question 19

A type of metamorphism
-A regional metamorphism induced by increase in pressure and temperature with non-uniform stress which produces foliated textures, mostly aerially extensive, and dominates convergent margins and associated fold and thrust belts.
-What are the products of this type of metamorphism?

Answer 19

Dynamothermal Metamorphism
-Greenschist, amphibolite, granulite, blueschist, eclogite

Question 20

A type of metamorphism that results from an increase in lithostatic stress caused by deep burial of rocks and produces non-foliated textures, affects regional subsiding basins that accumulate thick sequences of sediments and volcanic debris, and usually starts at temperatures -150 °C to 300 °C and gradational with diagenesis at depths of about 8 km.
-What are the products of this type of metamorphism?

Answer 20

Burial Metamorphism
-Non-foliated rocks with low temp. mineral assemblages

Question 21

A type of metamorphism
-A local form of metamorphism generated by explosive volcanic eruptions relatively rare collisions or of extraterrestrial objects with Earth, causing a high strain rate.
-What are the products of this type of metamorphism?

Answer 21

Impact Metamorphism
-“Impactites”, breccias, lamellae, shocked quartz pseudotachylites, coesite, stishovite

Question 22

A type of metamorphism that is Induced primarily by non-uniform stress in fault zones and shear zones, where the high strain rate is mostly local but extend to a regional scale in large faults or shear zones, and most likely recur in the same fault or shear zone.
-What are the products of this type of metamorphism?

Answer 22

Dynamic Metamorphism
-Cataclasites, pseudotachylites, mylonites