GEOLOGY110 EXAM1 UWEC Notes, 2024-2025

GEOLOGY110 UWEC Notes, 2024-2025

CHAPTER 1-2:

What is a Supernova?

Supernova: The explosive death of a massive star. It releases heavy elements (like iron, nickel, and uranium) into space, which later become part of planets. 

CHAPTER1-2

What are the Minerals and their percentages of Silica?

Mafic: 50%

Intermediate: 60%

Felsic:70%

CHAPTER 1-2:

What is the event that causes the cosmic abundance of elements?

Supernova

CHAPTER 1-2:

S vs R Process in Stellar Evolution:  

What is the S-Process and why does it happen?

What is the R-Process and why does it happen?

S-Process (Slow Neutron Capture): Happens in older, stable stars, forming elements up to bismuth. 

R-Process (Rapid Neutron Capture): Happens in supernovae, forming heavier elements like uranium and gold. 

Processes also determines how elements are formed in stellar environments.

CHAPTER 1-2:

What is the Solar Nebula?

A cloud of gas and dust that collapsed to form our solar system. 

CHAPTER 1-2:

What are Chondrite Meteorites?

The oldest and most primitive meteorites, containing chondrules (small, round mineral grains formed in space). 

CHAPTER 1-2:

What are Chondrules? What minerals are in them?

Small round iron nugget things. Contains Olivine, Pyroxenes, Feldspar, Kamacite, Taenite, Iron, Nickel

CHAPTER 1-2

What is the Cosmic Abundance of the Elements

It is the distribution of elements in the universe, caused by a supernova

CHAPTER 1-2

Refractory vs Volatile Elements:

What are they?

• Refractory: High melting points, condense first (e.g., Ca, Al, Ti).Creates Solid Planets

• Volatile: Low melting points, condense later (e.g., H, He, C, N) Creates Gassy Planets

CHAPTER 1-2

Explain and describe the differences between Minerals, Liquids, Vapors

• Minerals: Solids with a crystal lattice structure.

• Liquids: Atoms touching but not in a lattice.

• Vapors: Atoms widely spaced, no fixed shape.

CHAPTER 1-2

What is temperature?

• A measure of molecular energy; impacts mineral formation. (higher temp = more motion). 

CHAPTER 1-2:

What are Iron Meteorites composed of?

They are Almost entirely iron & nickel (from planetary cores). (KAMACITE and TAENITE)

Known as Chondrites

CHAPTER 1-2:

What are Stony Meteorites composed of?

Silicate-rich, can be chondrites (primitive) or achondrites (differentiated). 

Known as Achondrites

CHAPTER 1-2:

What are Stony Iron Meteorites composed of?

A mix of iron and silicates (from planetary mantles). 

CHAPTER 1-2

Do Chondrites contain Chondrules?

YES

CHAPTER1-2

Do Achondrites contain Chondrules?

NO

CHAPTER1-2

Iron and Nickel are more abundant in _____(Chondrites OR Achondrites) because they have______.

Chondrites

Chondrules

CHAPTER1-2

Explain Earth’s Origin

Formed by accretion of dust and rock, then differentiated into a core, mantle, and crust. 

CHAPTER1-2

Explain the role of Density and Oxygen/Differentiation in determining planetary composition.

• Oxygen plays a key role in determining planetary composition.

• Heavy elements (Fe, Ni) sank to form Earth’s core, lighter elements (Si, O, Mg) formed the mantle and crust.

CHAPTER1-2

What is are the Key Chemical Composition of the Earth and what is the most abundant element?

Key elements include: Si, Fe, Mg, Ca, Al.

The most abundant is oxygen, critical for forming silicate minerals.

CHAPTER1-2

What are the common minerals in the Earth and Meteorites?

• Olivine (Mg,Fe)₂SiO₄ 

• Pyroxene (Mg,Fe)SiO₃ 

• Feldspar (K,Na,Ca)AlSi₃O₈ 

CHAPTER1-2

What is the role of Oxygen in planetary bodies and the formation of iron cores?

Oxygen determines how iron behaves (metallic or oxidized state).

CHAPTER1-2

What is the difference between Terrestrial and Gaseous Planets

• Terrestrial: Small, rocky (Mercury, Venus, Earth, Mars).

• Gaseous: Large, mostly H/He (Jupiter, Saturn, Uranus, Neptune).

CHAPTER1-2

What is the difference between Venus, Earth, Mars, and Jupiter

• Venus: Thick CO₂ atmosphere, extreme greenhouse effect.

• Earth: Moderate climate, liquid water.

• Mars: Thin atmosphere, cold, evidence of past water.

• Jupiter: Gas giant, no solid surface.

CHAPTER1-2

Explain the origin of the moon

A Mars-sized body collided with Earth, ejecting debris that formed the Moon.

CHAPTER1-2

Why does the Moon have a tiny iron core

Impact stripped away most of the Moon’s iron, leaving a silicate-rich body.

CHAPTER1-2

What makes up the light and dark areas of the moon?

Light: Feldspar, no iron causes the lightness

Dark: Olivine, Pyroxenes, Feldspar, which makes up Basalt. Iron from the Olivines and Pyroxenes make the surface dark.

CHAPTER1-2

Why is Venus so Hot

• Thick CO₂ atmosphere, extreme greenhouse effect.

CHAPTER1-2

What are the causes of Potential Sites for Life in the Solar System? (Three causes, OWE)

Oxygen, Water, Energy

CHAPTER1-2

Why does Saturn have Rings? What are they made of?

It has rings due to tidal forces and its strong gravity.

It is made up of ice, possibly from shattered moons

CHAPTER1-2

Why is Io Active? (Io is Jupiter’s Moon)

Most volcanically active due to tidal heating from Jupiter’s Gravity.

CHAPTER1-2

Why are Dwarf Planets volatile-rich and icy

Formed in cold regions, retaining water and other volatiles

CHAPTER3-4

What is Paleomagnetism?

Earth’s magnetic field is recorded in rocks, revealing past pole positions. 

CHAPTER3-4

What is the Magnetic Polarity Reversals

The north and south magnetic poles switch over time, recorded in ocean floor basalt. 

CHAPTER3-4

What is Magnetic Stratigraphy

Layers of rock record Earth’s magnetic history. 

CHAPTER3-4

What is Seafloor Spreading (how we make oceanic crust)

Plates Pull Away (DIVERGENT)

New oceanic crust forms at mid-ocean ridges.

CHAPTER3-4

What are key characteristic of the Continental Crust

60% silica, Intermediate

Made of Granite (mostly Feldspar, not really Olivine and Pyroxene)

30-70 Km

Continental crust forms from water-induced melting. 

Cannot mix back into Earth's interior. 

CHAPTERS 3-4

What are key characteristic of the Oceanic Crust

50% Silica, MAFIC

Made of Basalt

10km Thick

Forms from decompression melting; At mid-ocean ridges, new oceanic crust forms as magma rises and cools.

Can subduct (sink) back into Earth's interior when it becomes dense enough. 

CHAPTER3-4

Plate Tectonic Boundaries

What is a Divergent Boundary and what does it cause?

Two plates move apart.

Plates pull apart → new oceanic crust forms. 

CHAPTER3-4

Plate Tectonic Boundaries

What is a Convergent Boundary and what does it cause?

One plate sinks under another → continental crust forms. 

Older and Colder one sinks because it is more dense

CHAPTER3-4

Plate Tectonic Boundaries

What is a Subduction Zone and what does it cause?

Oceanic plates sink, creating volcanic arcs. Makes continental crust

CHAPTER3-4

Explain Earth’s Interior

Lithosphere, Aesthenosphere, Rheologic Boundary,

• Lithosphere: Brittle, includes crust and upper mantle. 

• Asthenosphere: Ductile (flows), below the lithosphere. 

• Rheologic Boundary: The 1300°C boundary between brittle (lithosphere) and ductile (asthenosphere). 

CHAPTER3-4

What is Decompression Melting?

Decompression Melting: As mantle rises, pressure drops, and it melts → forms basalt

CHAPTER3-4

How does Serpentine form?

Water reacts with Olivines and Pyroxenes

CHAPTER3-4

What is the Dehydration and Melting

• Serpentine breakdown releases water → triggers magma formation

CHAPTER3-4

What is MORB (Mid-Ocean Ridge Basalt):

Basalt formed at divergent boundaries. Basaltic lava from decompression melting at ridges.

CHAPTER3-4

What is the Arc Magmatism and how does it relate to subduction zones and creating Continental Crust?

Subduction drives magmatism → volcanic arcs→ Creates continental crust

CHAPTER3-4

Why Continental Crust Floats:

Less dense than oceanic crust (like a rubber duck). 

CHAPTERS3-4

What is the difference between Basalt and Andesite

• Basalt: 50% silica, rich in olivine & pyroxene. Forms oceanic crust

• Andesite: 60% silica, more feldspar, forms continental crust. 

 

CHAPTERS3-4

What are the measurements of the Oceanic Lithosphere and Continental Lithosphere?

Oceanic Lithosphere: Max 100km

Continental Lithosphere: max 200km