IGNEOUS PETROLOGY (MAGMATIC DIFFERENTIATION)

Question 1

A process by which a variety of rock typs are produced from an originally HOMOGENOUS magma (Moorehose, 1952) which occurs as soon as the magma leaves the source

Answer 1

Magmatic Differentiation

Question 2

Process that causes Magmatic Differentiation

Answer 2

1) Fractional Crystallization
2) Magma Mixing
3) Crustal Assimilation or Contamination
4) Distinct Melting events from Distinct Sources
5) Various Degrees of Partial Melting
6) Liquid Immiscibility

Question 3

What is Fractional Crystallization?

Answer 3

Crystals are removed from the melt thus will not react anymore with it effectively changing its composition

Question 4

Mechanism of FC

Answer 4

1) Gravity Settling
2) Crystal Flotation
3) Gas Streaming or Stripping
4) Inward Crystallization

Question 5

When two or more magmas w/ different chemical composition come in contact w/ one another producing compositionally intermediate magma

Answer 5

Magma Mixing

Question 6

What could be the mixing mechanism of magma?

Answer 6

Convection generated by difference in temp of the two magma

Question 7

Inhibitor of Magma mixing

Answer 7

Temp Contrast
Density Contrast
Viscosity Contrast

Question 8

Evidences of Magma Mixing

Answer 8

1) Mingling of Magmas - Marble Cake
2) Disequilibrium Mineral Assemblage
3) Reverse Zoning in Minerals
4) Glass Inclusion - Trapped Liquids
5) Chemical Evidences

Question 9

Chemical Composition of a magma controls

Answer 9

Minerals Present

Question 10

Cooling rate controls

Answer 10

Texture of the Final Rock