GEOL 121 FINAL

Crust —>Lithosphere —>Asthenosphere —> Mantle —> Outer Core —> Inner Core

Earth’s Interior Structure Formation

1. Climate system – Atmosphere, oceans, land, and ice.

2. Plate tectonics – Earth's crustal movements.

3. Geodynamo – The magnetic field generated by Earth's core.

What are the key geosystems in the Earth System?

the Principle of Uniformitarianism

"The present is the key to the past." The same geological processes we see today also happened in the past.

The Earth System

includes all parts of our planet and how they interact. It is an open system, exchanging energy and matter with space.

Crust

Outermost layer, varies in thickness and composition, depth about 0-70 km.

Mantle

Layer of hot, viscous rock, depth about 70-2900 km.

Outer Core

Liquid layer of iron and nickel, depth about 2900-5150 km.

Inner Core

Solid, iron-nickel alloy, depth about 5150-6371 km.

Mohorovicic discontinuity:

the boundary between the crust and mantle where seismic velocity increases by 1 km/s abruptly to 8 km/s marking the switch from gabbro to peridotite.

P waves(Primary Waves)

Longitudinal Waves;Compressional, travel through solids and liquids.

S-waves (Secondary waves)

Shear, travel only through solids.

Alfred Wegner

developed the theory of Continental Drift

Cation

Positively Charged Ion

Anion

Negatively Charged Ion

Covalent Bonds

Electrons are Shared

ionic bonds

electrons are transferred, opposites attract

metallic bonds

electrons are shared, but free to mingle

Crystallization

atoms of a gas or liquid come together in the proper arrangement to form a solid substance with an orderly three-dimensional array.

Hardness

resistance to scratching relative to Mohs scale

Lustre

the way a mineral reflects light.

Cleavage

tendency of a crystal to split along planar surfaces (planes of weakness). Perfect, excellent, good, fair, poor, none.

Streak

color that a Mineral displays when scratched along a black or white surface

Rocks

naturally occurring solid aggregates of minerals, or in some cases, non-mineral solid matter.

Texture and Composition

Rock Identity is determined by: BLANK and BLANK

Igneous
Sedimentary
Metamorphic

3 Groups of Rocks

Bedding

vertically stacked layers of sedimentary rock with different types of sedimentary structures in each layer

Burial

the preservation of sediment within a sedimentary basin.

Diagenesis

process that converts sediment to sedimentary rocks.

Compaction
Cementation

Lithification includes:

1. Igneous Rocks

Rock Type Formed from cooling magma/lava.

2. Sedimentary Rocks:

Rock Type Formed from particles or dissolved minerals.

3. Metamorphic Rocks

Rock Type Altered by heat & pressure.

1. Hardness (Mohs Scale).

2. Cleavage (splitting along planes).

3. Fracture (irregular breakage).

4. Luster (how light reflects).

5. Color.

6. Streak (color of mineral powder).

7. Density (Specific Gravity).

8. Crystal Habit (shape of mineral growth).

Name at least 5 physical properties used to identify minerals

Divergent Boundaries

Plate boundaries that move apart(eg. Mid-Atlantic Ridge)

Convergent Boundaries

Plate boundaries that collide (e.g., Himalayas)

Transform Boundaries

Plate boundaries that slide past each other (e.g., San Andreas Fault).

the Rock Cycle

1. Igneous rocks → Weathering & erosion → Sedimentary rocks.

2. Sedimentary rocks → Heat & pressure → Metamorphic rocks.

3. Metamorphic rocks → Melting → Igneous rocks.

Metamorphic rocks → Melting → Igneous rocks.

The Rock Cycle starting from Metamorphic Rocks

Sedimentary rocks → Heat & pressure → Metamorphic rocks.

The Rock Cycle starting from Sedimentary Rocks

Igneous rocks → Weathering & erosion → Sedimentary rocks.

The Rock Cycle starting from Igneous Rocks

1. Weathering – Breakdown of rocks.

2. Erosion – Movement of sediments.

3. Transportation – Carried by wind, water, or ice.

4. Deposition – Sediments settle.

5. Burial & Compaction – Layers compress.

6. Diagenesis – Chemical changes turn sediment into rock.

What are the processes that form sedimentary rocks?

1. Continental Environments: Lakes, rivers, deserts, glaciers.

2. Shoreline Environments: Deltas, beaches, tidal flats.

3. Marine Environments: Deep-sea, continental shelf, organic reefs.

What are the types of sedimentary environments?