Ch 4b: Rocks Flashcards

(88 cards)

1
Q

How to identify rocks

A

look at texture, mineralogy and chemical composition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is texture

A

pattern, internal patterning, orientation of the crystal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Mineraology

A

what are the minerals in it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Rocks

A

Solid, cohesive aggregate of crystals or grains of one or more. Exception: volcanic glass (non-crystalline rocks)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Types of rocks:

A

igneous, sedimentary, metamorphic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The rock cycle

A

Transition of a rock type into another rock type

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Processes:

A

sedimentary, metamorphic, igneous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Sedimentary Process:

A

weathering, erosion, transportation, sedimentation, deposition, lithification, precipitation, diagenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Metamorphic Process:

A

re-crystallization, deformation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Igneous Process:

A

melting, crystallization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is Igneous Rock

A

crystallizations from molten rock.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Two forms of igneous rock:

A

extrusive (shoots out of the top) and intrusive (doesn’t make it to the surface)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Plutonic Rocks

A

Intrusive Rocks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Intrusive rocks

A

magma cools below the Earth’s surface. Surrounding rock acts as insulator. Magma cools slowly.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Magma cools slowly

A

crystals have time to grow large, coarse grained (Phaneritic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Phaneritic

A

if you can see the crystals with the naked eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Volcanic Rock

A

Extrusive rock

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Extrusive Rock

A

rapid cooling at the Earth’s surface in air or water.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Cools quickly and rapidly

A

microscopic crystals, fined grained (Aphanitic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Aphanitic

A

cannot see individual crystals with the naked eye (volcanic glass)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Two types of Extrusive Rocks

A

Lava, Pyroclastics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Pyroclastics

A

“fire fragments”, molten rock and minerals, ash

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Volcanic Ash

A

small minerals and volcanic debris. Unique to the volcano and the eruption.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Igneous Composition Types:

A

Felsic to Mafic, in between is intermediate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
rock type depends mainly on the proportion of:
free quartz, feldspars, Fe-Mg minerals
26
Felsic
free quartz, pink, (Green = ultrafelsic) 800
27
Intermediate
half and half dark and light colors
28
Mafic
Darker 1200
29
Isotropic
equal properties and equal dimensions | eg. Magnatic
30
Anisotropic
there is preferred orientations, no equal properties and equal dimensions eg. Sediment
31
Generalizations for Igneous
hard and isotropic due to crystalline texture, formed under conditions different at the surface. Brought to the surface via plate tectonics/volcanos
32
Regolith
unconsolidated rock layer
33
All rocks can be weathered by:
water, wind, ice, humans.
34
Rates are variable and controlled by:
properties of parent rock, climate, soil, time
35
Weathering
Break down of rocks at the Earth's surface, chemical and physical
36
Erosion
Process that loosens and transports rock fragments
37
Physical Weathering
physical breakup of material, creating fractures, creates more surface area, no compositional change, stress applied exceeds strength
38
Examples of physical weathering:
biological weathering, ice, mineral crystallizations, human activities
39
Chemical Weathering
minerals are dissolving and/or chemically altered. Change in particle size (clays are usually made). Weaken the integrity of the material
40
Chemical Reactions
solution: dissolve carbonate minerals by adding carbonic acid Hydrolysis: dissolve feldspars to form clays Hydration: add water without releasing material Oxidation: weathering of iron silicates to iron oxides
41
The more stable a mineral ....
the more slowly it reacts
42
Minerals that formed at a high temperature and pressure at depth are ...
unstable at the surface
43
Sediments:
unconsolidated material can be loosened and transported. Sediment characteristics can tell us material movement distance and duration
44
Sedimentary Structures
many types: dunes ripples, bioturbation (filled tunnels), mudcracks
45
Define diagensis
physical chemical changes that occurs during the conversion of sediment to sedimentary rock
46
Sedimentary Rocks: clastic/detrital
derived from pre-existing rocks
47
Clastic:
Clastic rocks are composed of fragments, or clasts, of pre-existing minerals and rock
48
Silt
gritty but falls apart
49
Clay
can be modelled
50
siltstone
if you break it, it has feathery wispy appearance
51
mudstone
breaks off into clumps
52
if its bigger than sands,...
its probably conglomerate
53
Soils
continued weathering of sediment: Naturally occurring, unconsolidated, mineral or organic, 10cm thick, at surface and can support plants
54
Soil development depends on:
climate, organisms, relief, parent material, time
55
Soil Structure:
distinct layers (horizons) are designated with modifiers (indepth horizons)
56
A horizon
zone of leaching or eluviation of mineral and organic matter. Maximum organic matter. Coarser texture than B
57
B horizon
Zone of accumulation or illuviation. Minerals (clay, oxides, salt) transferred from A
58
C horizon
Parent material, pre-existing sediment, shows some weathering due to soil processes.
59
Laterites:
wet, warm climates, deep red, highly leached clayey. Ultimate end product of chemical weathering. In the B horizon
60
If T and P increase due to:
increasing sediment layer thickness in basins, converging plates, proximity to hot magma bodies. Then enters metamorphsis.
61
Protolith
What you started with
62
Metamorphic Rocks
"changed form". Recrystallized in the solid state. May involve deformation.
63
Bigger Mica =
More shiny
64
Metamorphism is caused by
change in pressure and temperature
65
Main types of Mrocks
Contact, Regional
66
Contact MRocks:
cooling of a plutonic body
67
Plutonic:
magma chamber that is localized deep in the Earth. Temperature changes but not pressure
68
Regional MRocks:
Stress and heating related to plate tectonics. Large scale changes, mountains.
69
If Temperature Increase...
partial melting (different minerals melt at different temperatures. Addition of water lowers melting T, increasing P raises melting temperatures.
70
Andesitic:
intermediate between felsic and mafic
71
Rhyolitic: Felsic flow
more SiO2, doesn't flow well
72
Basaltic: Mafic flow
less SiO2, flows well
73
Pacific Ring of Fire
History's famous volcanic eruptions. Major climate and weather changes.
74
Most significant of the volcanoes are the
Stratovolcanoes
75
Stratovolcanoes
Composite volcano. Variable viscosity Increased water content Source of many volcanic hazards.
76
Phreatic
underground water in a zone of saturation
77
Large _____ eruptions can affect the global climate for several years
Pyroclastic-rich. | eg. Mount Pinatubo, PH, 1991
78
Height and amount of material emitted into the atmosphere can cause:
Reduced solar radiation (temporary). | Temperature drops related to SOx aerosols (Long-term)
79
Global Spread
Once in the stratosphere movement is global, effects become widespread
80
Volcanism is:
A suspected culprit for the Permian Extinction.
81
Tectonic Uplift
Creates obstacles that control atmospheric flow patterns. | eg. Rain shadow effect, chinooks, breezes.
82
Rain Shadow Effect
wet on one side of the mountain, dry on the other
83
Differential Heating
Plate tectonics changes relief. | Variable temperatures due to sun angles and heat capacity differences. Changes precipitation patterns
84
Uplift - Mass wasting
Steeper slopes promote material transfer, "land slides"
85
Effects of mass wasting
damming of rivers, removal of vegetation, soil disturbances
86
Carbon Cycle
Strongly affected by the rock cycle, common link between climate components.
87
Carbon Cycle: climate components
Weathering: removes it from atmosphere Lithification: confines it Biological Organisms: need it Metamorphism and Volcanic Eruptions: release it
88
Describe the process of Diagenesis
Sediment piles become thicker --> increases compaction, fluids may precipitate out and cement the pieces together.