Geology 120 Test 2

Front 1

A mineral must be...

Back 1

Solid
Naturally Occurring

Front 2

A mineral cannot be...

Back 2

Organic
Glass
Chemically Variable
A Rock or "Stone"

Front 3

Cleavage

Back 3

Plane of atomic weakness

Front 4

Aphanitic

Back 4

microscopic crystals
quick cooling
volcanic

Front 5

phaneritic

Back 5

visible crystals
slow cooling
plutonic

Front 6

Porphyritic

Back 6

mixed sizes
mixed cooling

Front 7

Felsic: Depleted in ______ and ______; and rich in ______ and _______

Back 7

Depleted in iron (Fe), magnesium (Mg)
Rich in silica (SiO 2), aluminum (Al)

Front 8

Igneous

Back 8

Any rock solidified from liquid “soup”of
elements

Front 9

Felsic: Color and Density

Back 9

Light colored and not dense

Front 10

Mafic: Depleted in ______ and ______; and rich in ______ and _______

Back 10

Depleted in SiO2, Al
Rich in Fe, Mg

Front 11

Mafic: Color and density

Back 11

Dark colored and dense

Front 12

Mafic: Definition

Back 12

Sima, “basic”

Front 13

Felsic: Definition

Back 13

Sialic, "acidic"

Front 14

3 basic characteristics of igneous rock
Hint: all three involve "crystal"

Back 14

1. interlocking crystals growing together
2. random crystal orientation
3. 100% crystallized
no pore space

Front 15

Two types of igneous rock

Back 15

Plutonic and Volcanic

Front 16

Plutonic igneous rocks are solidified at ______

Back 16

Depth of several km

Front 17

2 examples of where to find plutonic igneous rocks in CA

Back 17

Sierra Nevada, Yosemite

Front 18

Plutonic igneous rocks cooled quickly or slowly?

Back 18

Very slowly

Front 19

Large phaneritic crystals, cooled very slowly

Back 19

Plutonic igneous rock

Front 20

Microscopic aphanitic crystals, cooled very quickly

Back 20

Volcanic igneous rock

Front 21

Volcanic igneous rock cooled where?

Back 21

solidified near surface

Front 22

2 places to find volcanic igneous rock

Back 22

Hawaii and Mt Lassen

Front 23

Vesicles: Definition

Back 23

Bubbles

Front 24

Where do vesicles happen/form?

Back 24

Volcanic areas

Front 25

How do vesicles happen?

Back 25

as magma nears surface, gas released
gas bubbles, froths

Front 26

The big eight are all ______

Back 26

silicate

Front 27

Quartz

Back 27

hard (Moh’s7)translucent
forms points, 6-sided
fractures like glass (conchoidal)
no cleavage
equally hard in every direction

Front 28

K-spar, potassium feldspar

Back 28

2 cleavages @ 90o
relatively hard, opaque
grey, white, green, pink

Front 29

plagioclase

Back 29

2 cleavages @ 90o
relatively hard
opaque
grey, white

Front 30

biotite

Back 30

very soft
shiny jet black
flaky w/ 1 excellent cleavage

Front 31

muscovite

Back 31

very soft
shiny golden
flaky w/ 1 excellent cleavage

Front 32

pyroxene

Back 32

2 directions of cleavage @ 90o
dull, stubby
greenish

Front 33

olivine

Back 33

greenish, gray
weak aggregate, “sandy”
tiny, hard crystals

Front 34

amphibole

Back 34

jet black
elongated xtls
2 directions of cleavage @ 120o/60o

Front 35

Shale

Back 35

grains too small to see
DULL in color, esp compared to slate

Front 36

Sandstone

Back 36

grains sand size
Gritty
Hard but not that hard
Not very dense
POROSITY

Front 37

Conglomerate

Back 37

grains big
rounded pieces

Front 38

Biogenic
Meaning and how classified

Back 38

Derived from living organisms
Classified primarily by material

Front 39

Terrigenous
Meaning and how classified

Back 39

Derived from terra
Classified primarily by size

Front 40

Chert

Back 40

Made up of tiny siliceous shells
Can later crystalize and become quartz

Front 41

Limestone

Back 41

Made up of tiny clacareous shells
(Shells of organisms that made their cells out of glass)

Front 42

Diatoms

Back 42

Single cell, pin-head sized organism, precipitate shell out of glass, live for day or two, when dead are eaten and pooped on to bottom of ocean

Front 43

Collection of elements that compose a mineral:

Back 43

Na, Cl, Si, O, Fe, U

Front 44

Minerals are held together by __________
Also: Chemical equation

Back 44

Electric Bonding
Na4+Cl=NaCl0

Front 45

Metamorphic Rock

Back 45

Rock altered by heat and/or pressure, changing its mineralogy and texture.

Front 46

Slate

Back 46

Barely metamorphosed
Fine-grain
Slight shine

Front 47

Slate: Layering

Back 47

Flat sheets, original layering

Front 48

Phylite

Back 48

Slightly more cooked than slate
Rougher skin
Shinier

Front 49

Phylite's secondary minerals

Back 49

Garnet, pyrite

Front 50

Schist

Back 50

Very shiny (due to alignment of micas)
Wavy layering
A lot of secondary minerals: garnet, pyrite

Front 51

Gneiss

Back 51

Almost melted
Flat, not shiny (looks igneous)
Distinct foliation layers not found in igneous rocks

Front 52

What makes schist shiny?

Back 52

Micas

Front 53

How to recognize Augen Schist?

Back 53

Eye-like pattern

Front 54

Blueschist
Also: Why blue?

Back 54

High pressure
Low temperature (subduction zone)
Very Rare worldwide
Blue=mineral glaucophane

Front 55

Knockers: Definition and Cause

Back 55

Isolated rocks
Result of subduction

Front 56

Asbestos

Back 56

Group of 6 minerals
Stringy cleavage, like hair
Can be woven into cloth
Very fire resistant

Front 57

Color of deadly asbestos?

Back 57

Blue (crocidolite)

Front 58

Color of not so deadly asbestos

Back 58

Green (chrysolite)

Front 59

3 Minerals that compose serpentinite

Back 59

1. lizardite
scaly, light green
2. antigorite
darker, schistose
3. chrysotile
pale green parallel fibers
common asbestos

Front 60

Quartzite

Back 60

Metamorphosed sandstone
Very stable

Front 61

Marble

Back 61

Metamorphosed limestone
Reacts with acid rain

Front 62

Serpentinization

Back 62

Reaction of very mafic rock with water, peridotite, dunite

Front 63

Serpentinization: Specifics

Back 63

Water incorporated into min structure
large density loss: 3.3 2.7 g/cm
3300L water per 1m^3 serpentinite
low calcium, nitrogen
big energy release (exothermic)

Front 64

General formula for serpentinite

Back 64

General formula for serpentinite:
(Mg, Fe)^3 Si2O5(OH)4

Front 65

Serpentinite hospitable to plants?

Back 65

No, very toxic for most plants

Front 66

Where do diamonds form?

Back 66

Not close to Earth's surface

Front 67

What environment do diamonds need? (pressure/heat)

Back 67

Limited temperature/pressure range
depth: 90-120 miles
(45-60 kbars)
temperature: 900-1300 oC

Front 68

Facies

Back 68

Set of minerals which are stable at specific temperature/pressure ranges

Front 69

Most metamorphic rocks have narrow or wide range of minerals?

Back 69

Narrow

Front 70

Garnet

Back 70

(Fe, Mg)Al2(SiO4)3
iron-aluminum-silicate
dark-red, burgundy
rounded, like soccer ball

Front 71

Secondary mineral in metamorphic rocks
indicates level of _____________?

Back 71

Recrystallization

Front 72

Clay: 2 definitions

Back 72

1. anything smaller than 63 microns
2. Distinct mineral group:
Kaolinite, smectite

Front 73

Calcite

Back 73

Important mineral in sediments
3 directions of cleavage; not @ 90o
Soft, translucent
Fizzes vigorously in HCl

Front 74

Calcite makes what common thing?

Back 74

Shells

Front 75

Pillow Basalt

Back 75

glassy on rim
increasing xtl size toward center
more time to cool

Front 76

Where does pillow basalt tend to form?

Back 76

Where crust is pulling part

Front 77

Tuff

Back 77

Volcanic material ash, lapilli
Settles in low spots
Heat “welds”it back together

Front 78

Columnar Jointing

Back 78

Occurs when lava flows close to surface
cooling featurelava expanded when hot
frozen in sizecontracts when cooled

Front 79

Turbidite

Back 79

Deposits from submarine landslides
Thick flow of fine mud—big chunks
Gravity-driven “turbidity current”
Travels far into deep oceans

Front 80

How does turbidite settle

Back 80

Biggest pieces first, smaller on top