Earth Mat Flashcards - Ch 7

Question 1

Differentiate Holocrystalline, Hypocrystalline, and Holohayaline

Answer 1

Wholly crystal, half crystal half glass, and wholly glass respectively

Question 2

how large are pegmatites and what influences their formation

Answer 2

more than 30 mm, influenced by volatile amount

Question 3

different grain sizes of phaneritic texture

Answer 3

coarse 10-30 mm
medium 3-10
fine 1-3

Question 4

The process of which liquids are cooled to temperatures under the liquidus

Answer 4

Undercooling

Question 5

it is produced when ions form bonds during crystal formation and in turn, the main reason why seed crystals that just nucleated are remelted again

Answer 5

Heat of formation

Question 6

it is the rate at which elements migrate through magma

Answer 6

Diffusion

Question 7

elements that increase molecular linkage, and elements that decrease these linkages

Answer 7

network formers and modifiers respectively.

Question 8

it is a type of glassy igneous rock containing cristobalite seed crystals

Answer 8

Snowflake Obsidian

Question 9

an igneous texture wherein higher amounts of trapped water results in a cloudy form of obsidian

Answer 9

Perlitic texture

Question 10

a process in which volatiles nucleate into small bubbles

Answer 10

Vesiculation

Question 11

it is a location wherein bubbles constitute 70-80% of the magma volume

Answer 11

Fragmentation surface

Question 12

how do the amounts of vesicles influence the naming of rocks

Answer 12

pumice or scoria - more than 30%
vesicular - 5-30%
vesicle bearing - less than 5%

Question 13

Secondary fluids precipitating in vesicles

Answer 13

Amygdules

Question 14

aka airbourne pyroclastics

Answer 14

Tephra

Question 15

types of welded tuffs

Answer 15

unwelded tuffs - Random shard orientation
partially welded tuff - paarallelism among shards
densely welded tuffs - withflattening and parallelism

Question 16

statistics of Si and O and the major elements relative to its abundance on Earth

Answer 16

75% Crust weight
94.7% volume
other elements constitute 25% weight and 5.3% volume

as for the major elements: 99.2% weight

Question 17

examples of minor elements and which minor elements are present in mafic and felsic rocks

Answer 17

minor elements: 0.1-1% abundance
Cr, Mn, P, H, Ti

Mafic: Cr, Ni, Cu
Felsic: Li, Ba, Be

Question 18

it is the solid residual rock

Answer 18

Restite

Question 19

enumerate the LREEs and HREEs

Answer 19

LREEs: La, Ce, Pr, Nd, Sm
HREEs: Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu

Question 20

enumerate the LILEs and HFSEs

Answer 20

HFSEs: (immobile) Ti, Ni, Cr, V, Zr, Hf, Nb, Ta, Y
less than 0.2 radius/charge ratio

LILEs: (mobile) Cs, Ba, Rb, Sr, U, Pb, K, Zr, Th, Ta
greater than 0.2 radius/charge ratio

Question 21

Europium positive anomaly in a system signifies the presence of?

Answer 21

Plagioclase

Question 22

what does Sr87/Sr86 ratio differentiate?

Answer 22

it differentiates various magma environments
less than 0.7028 - ocean floor
0.7039 - ocean islands
0.7044 - island arcs

Question 23

what are the abundances of major minerals and accessory minerals

Answer 23

major - greater than 5% abundance in a rock
accessory - less than 5% such as oxides, sulfides.

Question 24

it is the first normative mineralogy classification

Answer 24

CIPW (Cross, Iddings, Pirsson, Washington) norm classification

Question 25

what are the Relative abundances terms for Aluminum relative to Alkalis?

Answer 25

Peraluminous - Al> Alkali metals
Metaluminous -Na + K < Al < Ca, Na, K
Subaluminous - Al = Na +K
Peralkaline - Al < Na + K

Question 26

Requirements to have QAPF and TAS diagram eligible of use

Answer 26

QAPF - more than 10% felsic minerals and less than 90% mafic minerals

TAS - Less than 2% water, and 0.5% Carbon dioxide