GEOLOGIC TIME SCALE

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GEOLOGIC TIME SCALE

• Learn Eras, Periods, Epochs, and Dates
• Please Come Over Some Day, Maybe Play Poker, Two
  Jacks Cover Two Queens
  
• Put Eggs On My Plate, Please Honey

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Ch 2 EARTH MATERIALS

• ATOMS

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Ch 2 EARTH MATERIALS

• ATOMS

Protons
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Ch 2 EARTH MATERIALS

• ATOMS

Protons
Neutrons
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Ch 2 EARTH MATERIALS

• ATOMS

Protons
Neutrons
Electrons
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Ch 2 EARTH MATERIALS

• ATOMS

Charge
Mass
Protons
Neutrons
Electrons
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Ch 2 EARTH MATERIALS

• ATOMS

Charge
Mass
Protons

0
Neutrons
-
Electrons
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Ch 2 EARTH MATERIALS

• ATOMS

Charge
Mass
Protons

1
0
Neutrons
1
-
0
Electrons
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EARTH MATERIALS

• Atomic Number - Number of Protons

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EARTH MATERIALS

• Atomic Number - Number of Protons
• Atomic Mass - Number of Protons Neutrons

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EARTH MATERIALS

• Atomic Number - Number of Protons
• Atomic Mass - Number of Protons Neutrons
• Isotopes - have the same atomic number, but a
  different mass number

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EARTH MATERIALS

• Chemical Bonding involves electrons

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EARTH MATERIALS

• Chemical Bonding involves electrons

Electrons are found in shells
Ideal levels of electrons in shells include 2, 8,
8, ...
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EARTH MATERIALS

• Ionic Bonding

An ion is a charged particle
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EARTH MATERIALS

• Ionic bonding
• e.g. Sodium (Na)
• 11 protons
• 11 neutrons
• 11 electrons

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EARTH MATERIALS

• Ionic bonding
• e.g. Sodium (Na)
• 11 protons
• 11 neutrons
• 11 electrons
• e.g. Chlorine (Cl)
• 17 protons
• 17 neutrons
• 17 electrons

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EARTH MATERIALS

• Ionic Bonding
• an ion is a charged particle
• Covalent Bonding
• sharing of electrons

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EARTH MATERIALS

• Ionic Bonding
• an ion is a charged particle
• Covalent Bonding
• sharing of electrons
• e.g. Cl2

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EARTH MATERIALS

• Ionic Bonding
• an ion is a charged particle
• Covalent Bonding
• sharing of electrons
• e.g. Cl2
• Chlorine has 17 protons, neutrons and
  electrons

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EARTH MATERIALS

• Atoms
• (e.g. O, Si, Ca, Na, C) form molecules

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EARTH MATERIALS

• Atoms
• (e.g. O, Si, Ca, Na, C) form molecules
• Molecules
• (e.g. SiO2 , NaCl, CaCO3, NaAlSi3O8)
• form minerals

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EARTH MATERIALS

• Atoms
• (e.g. O, Si, Ca, Na, C) form molecules
• Molecules
• (e.g. SiO2 , NaCl, CaCO3, NaAlSi3O8)
• form minerals
• Minerals
• (e.g. Quartz, Calcite, Feldspar) form rocks

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ROCKS

• What are ROCKS?
• n. mineral matter variously composed, formed in
  masses or large quantities in the Earths crust
  by the action of heat, water, etc.

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ROCKS

• Igneous
• Metamorphic
• Sedimentary

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ROCKS

• Igneous
• cooled from molten material
• intrusive vs. extrusive

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ROCKS

• Igneous
• Granite - intrusive
• - rich in silica
• - specific gravity 2.7
• (density in g/cc)

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ROCKS

• Igneous
• Granite
• Basalt - extrusive
• - low silica (Pyroxine, Olivine, Sodium
  Plagioclase)
  
• - specific gravity 3.0

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ROCKS

• Igneous
• Granite
• Basalt
• Andesite - extrusive
• - intermediate (Na/Ca plagioclase,
• biotite, amphibole)
• - specific gravity 2.8

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ROCKS

• Igneous
• Metamorphic - altered by pressure,
  temperature, chemical change
  
• often foliated or layered
• Pressure may come from mountain
• formation

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ROCKS

• METAMORPHIC
• Foliated
• (examples Slate, Schist, Gneiss)
• Non-Foliated
• (examples Marble, Quartzite, Greenstone)

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ROCKS

• Igneous
• Metamorphic
• Sedimentary Clastic from fragments of
• other rocks
• Nonclastic chemical or biological in
  origin

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ROCKS

• Clastic Sedimentary Rock Formation
• 1) Weathering
• 2) Transport
• 3) Deposition
• 4) Compaction
• 5) Cementation

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ROCKS

• NONCLASTIC SEDIMENTARY ROCKS
• Chemical
• (cherts, carbonates, limestones, halite,
  gypsum, etc.)
  
• Biological
• (diatomite, bioclasts, coal, etc.)

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ROCK CYCLE
Weathering
Igneous
Pressure
Chemical
Heat
Heat
Heat
Weathering
Sedimentary
Metamorphic
Pressure
Chemical
Heat
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SEDIMENTARY ROCKS

• Characteristics
• particle size (Wentworth Scale p.69, Levin)

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SEDIMENTARY ROCKS

• Particle size
• Texture
• -clastic - individual fragments
• - nonclastic - interlocking crystals grown
  together
  

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SEDIMENTARY ROCKS

• Particle Size
• Texture
• Sorting
• - poorly sorted - little time in transport
• -well sorted - more time in transport

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SEDIMENTARY ROCKS

• Particle Size
• Texture
• Sorting
• Parent Material
• - from which types of rocks were the
  sediments derived?

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SEDIMENTARY ROCKS

• Particle size
• Texture
• Sorting
• Parent material
• Particle Shape
• - how rounded are the grains?
• - reflects method, distance, how fast

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SEDIMENTARY ROCKS

• Particle size
• Texture
• Sorting
• Parent material
• Particle grain
• Color - red, yellow, brown - LAND
• - black - LOW OXYGEN
• - gray-green - MARINE

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SEDIMENTARY ROCKS

• CLASTIC SEDIMENTARY ROCKS
• Sandstones (Arkoses, Graywackes, Quartz)
• Shales - fine grain, from clay, silt
• Conglomerate - gravel cemented

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SEDIMENTARY ROCKS

• Nonclastic sedimentary rocks
• Carbonates - often associated with marine
• environments, may be produced in warm,
  shallow seas
  
• (e.g. limestone, dolomite)
• Diatomite - produced from algae with
• silica walls
• Coal - organic materials from dead plants
• Evaporites - salt, gypsum

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SEDIMENTARY STRUCTURES

• Grain Orientation
• long axis toward flow
• grains may be tilted to upstream

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SEDIMENTARY STRUCTURES

• Grain orientation
• Cross bedding
• current dominated deposition
• (e.g. deltas, dunes)

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SEDIMENTARY STRUCTURES

• Grain orientation
• Cross bedding
• Ripple Marks
• - shallow water deposition
• - symmetric ripples oscillation
• - asymmetric ripples direction of flow

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SEDIMENTARY STRUCTURES

• Grain orientation
• Cross bedding
• Ripple Marks
• Mud Cracks
• - alternating wet and dry conditions

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FACIES

• Even though strata have lateral continuity, the
  sediments also change laterally due to differing
  environmental conditions.

shale
sand
Lithofacies
cclam shells
c
c
s
s
s
c
c
s
s
c
s
sshark teeth
Biofacies
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SEDIMENTARY STRUCTURES

• THE KEY TO UNDERSTANDING SEDIMENTARY ROCKS IS
  THINKING ABOUT THE DEPOSITIONAL ENVIRONMENT
  
• sorted? particle size? parent? cement?
• pond? stream? ocean? wind? glacier?