Quiz 1 Flashcards

(57 cards)

1
Q

Endogenic process

A

Internal process that builds up landforms
Powered by the heat within the Earth

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

Exogenic process

A

External process that tears down landforms
Powered by solar energy

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

Superposition

A

Rocks get younger as you move up

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

Original horizontality

A

Sediments are originally deposited in horizontal layers. If they’re tilted, they moved after deposition

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

Cross-cutting

A

Cut rocks are older than the rock cutting them

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

Unconformities

A

A gap in time when no rock layers are present — often due to erosion or change in conditions

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

Universe’s age

A

13.8 bi

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

Earth’s age

A

4.6 bi

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

Catastrophism

A

Earth’s features were produced by sudden, worldwide disasters of unknowable causes that no longer operated; based on Archbishop James Ussher’s study of the Bible in the mid-1600s
Through this school of thought, the Earth was thought to be only a few thousand years old

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

Uniformitarianism

A

Forces that appear small could, over long spans of time, produce the same effects as those resulting from catastrophic events; from James Hutton in the late 1700s
“The present is the key to the past”

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

Earth layers, as defined by composition vs by physical properties

A

Composition: Crust, mantle, core
Physical properties/mechanical: lithosphere, asthenosphere, mesosphere, outer and inner core

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

Continental crust

A

Light, thick, old, complicated
Felsic silicate rocks

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

Oceanic crust

A

Heavy, thin, young, simple
Mafic silicate rocks

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

Mohorovic Discontinuity

A

Sharp boundary between crust and mantle

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

Lithosphere

A

Composed of uppermost mantle and crust; the “plates” in plate tectonics. Deforms brittely if at all

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

Asthenosphere

A

Weak substrate on which plates ride. Deforms plastically. “Solid, but mobile”

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

Isotasy

A

Refers to lighter crust floating on deeper mantle. The weight of the crust affects the position of the mantle

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

Inner core vs outer core

A

Inner core is solid, outer is molten. The movement of Fe in the outer core generates Earth’s magnetic field. The inner core of earth rotates at a different rate than the rest of the Earth. Together, they form most of Earth’s mass

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

Rock

A

Consolidated of one or more minerals

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

Mineral (definition/properties)

A

Solid, naturally-occurring, characteristic crystal structure (orderly atoms), generally inorganic, homogeneous

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

Crystalline

A

Any natural solid with an ordered, repetitive, atomic structure

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

Polymorph

A

Minerals with the same chemical composition but different structure

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

Mineral types

A

Silicates, carbonates, oxides, sulfides, sulfates

24
Q

Five most common minerals

A

Plagioclase feldspars: 39%
Potassium feldspars: 12%
Quartz: 12%
Pyroxenes: 11%
Amphiboles/Micas/Clays 5%, or nonsilicates are 8%

25
Ways for minerals to form
Change in temperature, crystallization from solutions in water, biological processes
26
Chemical formula and charge of a silica tetrahedron
SiO4, -4
27
Mafic silicates
Rich in iron and magnesium; darker in color/green: Olivine and Pyroxene
28
Felsic silicates
Have smaller proportions of iron and magnesium and higher proportions of silica and oxygen; lighter in color: Quartz and Feldspar
29
Most abundant elements in earth's crust
Oxygen (47%) and silicon (28%), followed by aluminum and iron
30
In ionic bonds (which form 90% of minerals), ______ of similar size can substitute for each other
Cations (smaller than anions); different cations form different mineral colors
31
Second most abundant mineral group in the earth's crust
Carbonates
32
Major minerals of carbonates
Calcite, aragonite, dolomite
33
Mineral examples of oxides
Hematite, magnetite, corundum
34
Mineral example(s) of sulfides
Pyrite, chalcopyrite
35
Mineral examples of sulfates
Gypsum, anhydrite
36
How many subclasses of silicate minerals are there? What distinguishes these subclasses from one another?
6 subclasses, based on the arrangements of the silica tetrahedra
37
Nesosilicates
Single tetrahedron; olivine and garnet (most important minerals in the upper mantle)
38
Inosilicates
Single chain: pyroxene Double chain: Amphibole
39
Phyllosilicates
Sheet structure, good basal cleavage
40
Tectosilicates
"Framework" structure; quartz and feldspar minerals are the most important groups
41
Key points to how the Earth was formed:
- Event triggered gravitational collapse of a cloud of dust and gas (a nebula), which formed a spinning disk as it collapsed; "nebular hypothesis" describes how our solar system evolved from the solar nebula - Collapse released gravitational energy that heats the center and goes on to form a star - Outer, cooler particles collide and build plants (and other bodies) (this is called accretion) - Younger stellar activity blows off any remaining gas and leaves an embryonic solar system - Rocky/terrestrial planets form in the hotter interior, gas/jovial planets form in the colder outer regions - Earth formed its layers because of temperature and density differences (Fe and Ni sank to form the core, molten rock rose to form the crust. While this was happening, a Mars-sized body hit the Earth (forming the moon)
42
Nucleosynthesis
Refers to how all elements before Fe (iron) were created. Under intense heat, atoms fused together to form other light atoms
43
Planetary differentiation
The processes of separating out different constituents of a planetary body as a consequence of their physical or chemical behavior, where the body develops into compositionally distinct layers. This process has occurred on planets, dwarf planets, an asteroid, and natural satellites.
44
Terrestrial vs Jovian planets
Terrestrial planets: inner planets, are more rocky, smaller Jovian planets: outer planets, gas and ice, bigger
45
Giant Impact Theory
Main theory of moon formation. Shortly after the Earth formed, a Mars-sized body impacted the earth, generating a cloud of dust and vapor that condensed and accumulated to form the Moon.
46
What three factors increase with depth of the Earth?
Density, temperature, and pressure
47
Is the mantle or crust more homogeneous? Why?
The mantle is more homogeneous because it convects.
48
Mantle
Made up of dense rocks (peridotite, silicates). Is a non-Newtonian fluid.
49
Cation
Atom that gives up electrons and has a positive charge
50
Anion
Atom that takes electrons and has a negative charge
51
Most stable form of bonding
Covalent bonding
52
Cleavage
The way a mineral breaks Note: In silicates, the O bonds are much stronger than the cation bonds, leading to planes of weakness
53
Properties used to identify minerals
Hardness, cleavage, fracture, luster, color, density, streak, and crystal habit
54
Fracture
Any break in a mineral that doesn't occur along a cleavage plane
55
Irregular fracture
Uneven surfaces
56
Conchoidal fracture
Smooth, curved surfaces
57
Luster
The way a mineral reflects light. Metallic, nonmetallic (glassy, glossy, greasy, waxy, pearly, earthy)