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Flashcards in Geo Unit 1 Deck (74):
1

What is the first step of the Scientific Method?

Form a hypothesis

2

What is a Theory?

Hypothesis that has been repeatedly confirmed

3

What is a Paradigm?

A comprehensive theory; pulls together seemingly unrelated things

4

What is a Scientific Law?

A theory that survives rigorous testing over time

5

Define Catastrophism

The idea that Earth evolved through a series of spectacular events (earthquakes, volcanoes, floods, etc.)

6

Define Uniformitarianism

The idea that current geological processes are responsible for the rock record

7

Are the rates of Uniformitarianism constant?

No

8

Is Earth a sphere?

No, it is a prolate spheroid shape (slightly flattened sphere)

9

What is the radius of the Earth?

+/- 4,000 miles

10

What was the first thing to happen after the "Big Bang"?

Hydrogen and Helium stabilized

11

What created more elements after H and He in the creation of the universe?

Fusion in older suns

12

How did the sun form?

Formed from a nebula collapse

13

When did Earth accrete to its present size?

4.6 Billion Years Ago

14

Define Accretion

Smaller pieces being joined by gravity

15

What was the homogenous body of primitive Earth made of?

Iron, Magnesium, Silicon, Oxygen, and gases

16

Was Earth hot or cold at first?

Cold

17

What was the "Big Thwack"?

An asteroid (Theia) collided with Earth, resulting in the formation of the moon.

18

What was the iron catastrophe?

The planet differentiated, with the iron melting and sinking to form the core, and silicon and oxygen rising to form the crust (leftovers, Mg Si + O, formed the mantle)

19

What is the outer layer of earth

The crust

20

How thick is the crust

7 to 70 km thick

21

What is the difference between continental and oceanic crust

The continental crust is thicker and buoyant, and the oceanic crust is thinner and more dense

22

What are the characteristics of the mantle

It is hot and plastic, dense from pressure

23

What are the two parts of the core made of

The outer core is liquid and the inner core is solid iron and nickel

24

What is the lithosphere

The thin layer underneath the crust

25

How far down do the tectonic plates reach?

The bottom of the lithosphere

26

What is the Asthenosphere?

The top layer of the mantle (under the lithosphere)

27

Geologists look at rock texture and mineralogy to...

determine history

28

What is rock texture?

The arrangement, sizes, and shapes of mineral grains

29

What are the three main classifications of rocks?

Igneous, Sedimentary, and Metamorphic

30

What is Igneous rock born of?

Fire

31

What are the two categories of Igneous rocks?

Intrusive and Extrusive

32

What defines Intrusive Igneous rocks?

They are plutonic, and formed from magma

33

What defines Extrusive Igneous rocks?

They are volcanic, and formed from lava

34

What is the difference between fast cooling and slow cooling Igneous rocks?

Fast cooling has small grains and slow cooling has big grains

35

What is the material that makes up Sedimentary rocks?

Older rocks that have broken down through weathering, erosion, and deposition

36

What is the process that turns sediment into solid rock?

Lithification

37

What are the three steps of Lithification?

Deposition, Compaction, and Cementation

38

What are the three types of Sedimentary rocks?

Clastic, Biochemical, and Chemical

39

What are Clastic Sedimentary rocks?

Gravel and Boulders

40

What are Biochemical Sedimentary rocks?

Ocean Floor and Reefs

41

What are Chemical Sedimentary rocks?

Chemicals leftover when water evaporates

42

What defines Metamorphic rocks?

They are changed by heat and pressure without melting (solid state recrystallization)

43

What are the two types of Metamorphism?

Regional (Heat) and Contact (pressure)

44

The "all world" supercontinent

Pangaea

45

Old evidence of Continental Drift?

Related rocks on different continents and Paleoclimates

46

Modern evidence of Continental Drift?

Paleomagnetism (magnetic reversals recorded in rock) and direct measurement of plate movement

47

How many big, rigid plates in the Lithosphere?

About a dozen

48

How much do the plates move in a year?

1 - 10 cm a year

49

Where does most geologic activity occur?

At and near plate boundaries

50

What are the three types of plate boundaries?

Divergent Margins, Convergent Margins, and Transform Margins

51

Define Divergent Margins

The plates are moving apart, with very active volcanism

52

What are the two types of Divergent Margins?

Continental Rifts and Sea-Floor Spreading

53

Define Convergent Margins

Plates running into each other

54

What are the three types of Convergent Margins?

Continent to Continent (mountains, large earthquakes), Oceanic to Continent (oceanic crust subducted, volcano chain), and Oceanic to Oceanic (older crust subducted, volcanic island arcs)

55

What maintains the size of Earth?

A balance between construction and destruction

56

Define Transform Margins

The plates slide past each other, with major earthquakes but no volcanoes

57

Define Ridge Push

Idea that heat forces the plates apart

58

Slab Pull?

Strong Gravitational Forces

59

Gravity Sliding?

Slight downhill

60

Metallic Bonds?

Closely packed atoms with drifting electrons

61

Van der Waals Bonds?

weak attraction

62

What are the three characteristics of Minerals?

1. Naturally Occurring
2. Inorganic Solid
3. Ordered Atomic Structure

63

What are rocks?

Combinations or aggregates of one or more minerals

64

What are the most abundant minerals in the crust?

Oxygen and Silicon

65

What are Silicate Minerals?

Minerals made with the Silica tetrahedron, make up 90+% of the crust

66

What are the five types of Silicate structures?

Isolated Tetrahedra, Single Chain of Tetrahedra, Double Chain, Sheets, and 3D Framework

67

What is made of a Double Chain Silicate?

Asbestos (i.e. Chrysotile(safe), Crocidolite and Amosite(bad) )

68

How are the Tetrahedra held together in Silicate structures?

With cations

69

What is the Piezoelectric Effect?

1. Pressure causes electrical polarity at surface of crystal
2. Applying a charge causes crystal to vibrate regularly

70

What are the Non-Silicate Minerals?

Carbonates, Sulfides + Sulfates, and Oxides

71

Define Carbonates

Carbon and Oxygen, weak bonds and soft minerals

72

Define Sulfides + Sulfates

Sulfur loses or gains electrons, bonds with wide variety of ions, especially Copper, Lead, and Zinc

73

Define Oxides

Oxygen combines with metallic cations, very resistant and durable minerals

74

What is the Mohs Hardness Scale

1. Talc
2. Gypsum
3. Calcite
4. Fluorite
5. Apatite
6. Orthoclase Feldspar
7. Quartz
8. Topaz
9. Corundum
10. Diamonds