Geology 101 Notes

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Geology 101

Universal Knowledge
Zoology
Political Science
Astronomy
History
Biology
Geology
Geography
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Examples of Time & Geology
* Sphinx
Precambrian Era: (4.5 billion)
* Ended 542 million years ago
* Started with no life and evolved bacteria & algae
Paleozoic Era: (542 – 251 MYBP)
* Fish, amphibians, etc. were early years
* Ended with the Greatest Extinction of all time
Mesozoic Era: (251 – 65 MYBP
* Dinosaurs ruled and small animals developed in end
* Ended with asteroid in Yucatan
Cenozoic Era: (65 – now MYBP)
* Rise of mammals and Great Glaciations
* Holocene = Rise of Man (last 15k years)

Natural Resources
* Most resources are: limited in quantity and non-renewable Earth’s Systems
* Atmosphere
* Hydrosphere
* Biosphere
* Geosphere
Earth’s Heat Engines
* External
* Energy form the sun
* Internal
* Energy from radioactive decay
Earth’s Interior
* Crust
* Thin outer rocky shell (solid)
* Variable thickness
* Mantle
* Hot solid
* Special “plastic” zone
* Fe, Mg, and Si rich minerals
* Core
* Outer Core
* Liquid, mostly iron
* Inner Core
* Solid, mostly iron
Rock vs. Minerals
* A mineral is a crystalline solid and is formed by natural geological processes * Has a specific chemical composition
* Has consistent physical and chemical properties
* A crystal is a mineral with shape properties
* A rock is a composite of one or more minerals
Atoms and Elements
* Elements
* Substances not divided by chemical reactions
* “Periodic Table” listing
* Atoms
* Smallest unit with properties of element
* Composed of 3 types of subatomic particles: protons, neutrons, and electrons * Molecules
* Combination of atom’s Atomic structure
* Nucleus
* Most of the atom’s mass
* Electrons
* Tiny fraction of atom’s mass
* Chemical vs. Nuclear reactions
* Involve only outer shell
Isotopes
* Elements
* Determined by # of protons in nucleus
* # of neutrons can vary for an element
* Isotopes are a change in # of neutrons in the nucleus
* May be stable if not stable it is radioactive
Chemical Bonding
* Characteristics
* Non-nuclear
* Controlled by outer-most shell
* Reactive = valence shell has empty slots
* Non-reactive = valence shell is filled
* Protons & electrons are unequal
* Positive or negative charges
* May stick or bond together
* Main Types (3)
* Ionic – transfer one to another
* Covalent – shared between atoms
* Metallic – free flowing
Composition of Earth’s Crust
* 81% of all atoms are Oxygen & Silicon
* 96% + of all atoms include: O, Si, Fe, Al, Ca, Na, K, and Mg * Common mineral types are Silicate: Si & O
Non-Silicate Minerals
* Carbonates (CO )
* Sulfates (SO )
* Sulfides (S)
* Oxides (O)
* Native Elements = one element
* Rock forming minerals = 4000+ known
Minerals
* Feldspars
* Most abundant group
* Framework silicate shares 4 Oxygen
* Micas
* Sheet silicate shares 3 Oxygen
* Quartz
* Framework silicate shares 4 Oxygen
* Olivine
* Common Mantle Rock
Mineral Properties
* Color
* Visible tint
* Poor identifier
* Streak
* Smear when scraped
* Luster
* Reflected light off mineral surface
* Hardness
* Scratch resistance
* 1 (soft) – 10 (hard)
* Crystal Form
* External geometric form
* Cleavage
* Breakage (Mica)
* Fracture
* Irregular breakage (conchoidal)
* Specific Gravity
* Density relative to water
* Magnetism
* Chemical Reaction
* Calcite “fizz”
Chapter 3: Igneous Rocks, Intrusives, & Extrusives
Start of Exam 2
* Igneous Rocks
* Characteristics
* Rock texture = grain
* Texture controlled by cooling rate
* Extrusive rocks cool rapidly above ground...
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