Introduction to Physical Geology (GEOL 1) Dr. Ryan J. McCarty

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1 Introduction to Physical Geology (GEOL 1) Dr. Ryan J. McCarty 1

2 100 or so million years later, First (and giant) stars form After the first 20 minunets of the big bang H, He, Li, Be

3 Type of H Type of H

4 Supernovas, Kilonovas

6 Why is the composition of the Earth so different on the crust? Crust Only Entire Earth 6

7 1 2 3

8 8

9 Earth by structure 9

10 Earth by composition 10

11 11

12 Compositional layers in pictures 12

13 Kola superdeep borehole 12 KM Deep Center of Earth: 6,400 KM deep 13

14 Crust Only Entire Earth 14

15 How do we know the composotion of Earth?

16 Chondrites and Meteorites 16

17 Phases of mater Solid Melting Liquid Evaporation Vapor Freezing Condensation

18 Building the earth, a bit like cooking Basic ingredients Atoms (elements) Each dish Minerals Full meal Rocks 18

19 Atoms don t look like this! Nucleus Electron cloud 19

20 Pin head nucleus 747 electron cloud 20

21 Earth electron cloud 747 nucleus 21

22 Charge (geology always adds to zero) Blue = Positive, Red = Negative Size 22

23 Thinking Diversity In cooking: How do we measure ingredients in the United States? How do they measure ingredients in Europe? How do scientists measure ingredents?

24 Our solar system By atoms By mass Hydrogen Helium Oxygen Carbon Nitrogen Neon Silicon Magnesium Iron Sulfur Hydrogen Neon Magnesium Magnesium Aluminium Argon Calcium Sodium Nickel

25 Since most of geology deals with Blue = Positive, Red = Negative Talking geology in terms of atoms Chemical formula (A bit like a recipe for cooking) 25

26 Periclase: Na = 0.00 O = peak Al = 0.00 Mg = 0.49 Si = 0.00 Corundum Na = 0.00 O = peak Al = 0.33 Mg = 0.00 Si = 0.00 Spinel Na = 0.00 O = peak Al = 0.28 Mg = 0.14 Si = 0.00 Jadeite Na = 0.11 O = peak Al = 0.09 Mg = 0.00 Si = 0.21 Galena Na = 0.00 O = no peak Al = 0.00 Mg = 0.00 Si = 0.00

27 Minerals 27

28 Bonding in minerals Covalent (Strongest) Ionic Van der Waals (Weakest)

30 4 Strong bonds 3 Strong bonds

31 Bonds have energy: In order to break or make, there is an energy cost

32 Bonds have energy: In order to break or make, there is an energy payout

33 Size, bond, composition 33

34 By definition a mineral is: Naturally occurring Inorganic Solid Crystalline Ordered internal structure Definite chemical composition (Rock = a solid aggregate of minerals + other thigns) 34

35 Ordered structure (crystalline) 35

36 Silicon tetrahedron SiO 2 36

37 Silicon tetrahedron 37

38 How is this used to make minerals? Red spheres = -2 Blue spheres = +4 What is the charge on the silicon tetrahedron? 38

40 -2 Total? We need more + atoms

41 Total?

42 New total? 42

43 Total? =

44 Olivine Quartz 44

45 The Silicon tetrahedron is a basic building block 45

46 No extra! 46

47 Red spheres = -2 Blue spheres = +4 If it is touching a grey sphere, count it as half Sheet silicates 47

48 48

49 49

50 50

51 How do we ballance them out? 51

52 Which silicates need the most other elements? 52

53 Experience with Cleavage?

54 Cleavage: 1 plane 54

55 55

56 56

57 57

58 No cleavage, only fracture 58

59 59

60 But pretty looking crystal faces 60

61 Crystal growth (Adding layer by layer) 61

62 Outward crystal growth fills available space Often the resulting crystal shape is governed by surroundings Open space Good crystal faces grow Confined space No crystal faces 62

63 Where do minerals grow and form? 63

64 Where do minerals grow and form? 64

65 Mineral growth with time = longer = larger What do we need to cause slow mineral growth? 65

66 Shorter? Too Short? 66

67 Geo-Glass: Where might it form?

68 Glass and amorphous materials Basalt (a volcanic rock) Mayon volcano Libyan desert 68

69 69

70 70

71 Chemical Composition, Pressure, Temperature 71

Johannes Kepler used a primitive form of thermodynamics to estimate the age of the Earth based on its current temperature (or current atleast in 1500s).

72 Johannes Kepler used a primitive form of thermodynamics to estimate the age of the Earth based on its current temperature (or current atleast in 1500s). His idea was that if we could estimate how much heat would have been created during the formation of Earth, then we could use its current temperature and estimate how much it has cooled off. His guess, Earth was formed in 3993 BC 72

73 How much heat he guessed Earth has was wrong. What sources of heat can be found on Earth?

74 Fission (NOT Fusion) 74

75 Chemical Composition, Pressure, Temperature 75

76 Why didn t all the elements separate out? Crust Only Entire Earth 76

77 Water and Alcohol 77

78 100 C 75 C 50 C 25 C 0 C -25 C -50 C -75 C -100 C -125 C 78

Introduction to Physical Geology (GEOL 1) Dr. Ryan J. McCarty

Introduction to Physical Geology (GEOL 1) Dr. Ryan J. McCarty 1 Science and Learning 2 How to learn Learning new things requires some work Best way to learn new things is build on things you already know