Geology Final Review

What is science?

A systematic way of understanding the natural world through observation, testing, and evidence

What is a theory in science?

Best explanation based on all data

What is a hypothesis?

a way to test questions

What are the different layers within the Earth?

• Crust

  • Continental crust

  • Oceanic crust

• Lithosphere (crust + uppermost mantle)

• Asthenosphere (soft, flowing layer)

• Mantle (includes Dʺ layer at base)

• Outer Core – Liquid

• Inner Core – Solid

What kinds of waves do geologists use to study the interior of the Earth?

P waves and S waves

P-waves

travel through solids & liquids

S-waves

travel through solids only

What drives the movement of the tectonic plates?

Mantle convection, slab pull, ridge push

Where is oceanic crust formed?

Mid-ocean ridges (divergent boundaries)

Where is the oceanic crust destroyed?

Subduction zones

Where is continental crust formed?

Volcanic arcs, collisions, magmatism

Why is oceanic lithosphere (crust) subducted beneath continental lithosphere?

It is denser and thinner, making it heavier and less buoyant than the thicker, lighter continental crust

What happens when two pieces of continental crust collide?

Massive mountain ranges through intense folding, faulting, and crustal thickening

The three types of plate boundaries

Transform, convergent, divergent

What plate boundaries most often produce earthquakes?

Transform and Convergent

What plate boundaries produce fewer and less energetic earthquakes?

Divergent

What material is good to build on in earthquake-prone areas?

wood, steel, and reinforced concrete

What isn’t good to build on in earthquake-prone areas?

unreinforced brick, stone, and adobe

What plate boundaries most often produce volcanoes?

Convergent and Divergent

What plate boundaries do not produce volcanoes?

Transform

What is the definition of a mineral?

Naturally occurring, Inorganic, Solid, Definite chemical composition, Ordered crystal structure

Which physical properties are unreliable for identifying a mineral?

Color

Which physical properties are reliable for identifying a mineral?

Hardness, streak, cleavage

What are the natural planes of weakness in a mineral called?

Cleavage

Where can you find igneous forming?

from magma/lava

Where can you find sedimentary forming?

from sediments

Where can you find metamorphic forming?

at tectonic plate boundaries, subduction zones, and near igneous intrusions altered by heat/pressure

What is the conversion of sediment into sedimentary rocks called?

Lithification

Where is sandstone typically deposited?

in beaches, rivers, deserts

What are some sedimentary rock resources?

Coal, oil, natural gas, building stone

How does metamorphic foliation form?

direct pressure

Where is chemical weathering most efficient?

in warm, wet climates

Where is physical weathering the fastest?

in cold or dry climates

Syncline

trough (youngest in center)

Anticline

arch (oldest rock in center)

Dome

circular anticline

Basin

circular syncline

Monocline

step-like fold

What features do meandering streams have?

Cut bank, Point bar, Oxbow lakes

Cut bank

erosion, outside curve

Point bar

deposition, inside curve

Sinkholes typically form in what kind of rock?

Limestone (karst terrain)

What does a hill look like on a topographic map?

closed circles, elevation increases inward

What does a hill look like on a depression map?

closed circles with hash marks

What is relative dating?

the science of determining the chronological order of past events, rocks, or fossils without determining their precise numerical age

What is absolute dating?

a specific numerical age or age range in years for rocks, fossils, or sediments

What does relative dating tell us?

Determines order, not exact age

The Principles of Superposition

oldest on bottom, youngest on top

Lateral Continuity

layers extend outward

Original Horizontality

layers deposited flat

Intrusive Relationships

intrusions are younger

Cross-Cutting Relationship

any geological feature—such as a fault, dike, or igneous intrusion—that cuts across or disrupts rock layers is younger than the rocks it penetrates

What is an unconformity?

missing time in rock record

What are the three kinds of unconformity?

Angular unconformity, Disconformity, Nonconformity

When was the last ice age?

Pilestocene, about 12,000 years ago

What features are attributable to the last ice age?

Great lakes

Desert geology

Wind shaped environment and places