Rocks, Dating, & the Law of Superposition
Soil Layers & Key Terminology
Climate (Change), Feedback Loops, & Climate Proxies
Plate Tectonics & Continental Drift
Earth Systems & more Plate Tectonics
100
What is the law of superposition?
Oldest rock layers are at the bottom
- Youngest layers are at the top
- Helps determine relative ages of rock layers
100
What is a half-life?
The time it takes for half of the atoms in a sample of a radioactive substance to decay into a more stable form.
100
What is a positive feedback loop?
Changes that amplify the original effect
100
What is the theory of Plate Tectonics?
Theory explaining movement of Earth's lithosphere which is divided into different plates
100
What does the movement of Tectonic Plates cause?
The movement of tectonic plates can cause earthquakes and volcanic activity, especially along plate boundaries.
200
What is the rock cycle?
A continuous geological process where rocks transform between different types
- Key transformation processes:
* Melting/cooling - Igneous
* Weathering and Erosion - Sedimentary
* Metamorphism/heat and pressure - Metamorphic
200
What is Sedimentary deposition?
Particles settle out of water or air.
200
What is a Negative Feedback Loop?
Changes that counteract the original effect
200
What are the types of Plate boundaries?
Types of boundaries:
- Divergent (plates moving apart)
- Convergent (plates colliding)
- Transform (plates sliding past)
200
What is a Subduction Zone?
Areas where one tectonic plate is forced under another plate and sinks into the mantle. This process recycles the oceanic crust.
300
What are the 2 main types of dating?
Relative Dating:
* Compares rock layer positions
* Uses index fossils (one example) - Are fossils of organisms that we know the exact age of when they lived on earth, therefore if you find them in a layer of sedimentary rock, you know that layer must have formed during that time interval.
- Absolute Dating:
* Determines exact age in years
* Uses radiometric techniques
* Tree Rings, Varves
300
What are the CLORPT soil formation factors?
- CL – Climate: Temperature and precipitation influence how quickly rocks weather and organic material decomposes. Warm, wet climates produce soil faster than cold, dry ones.
- O – Living Organisms (Biota): Plants, animals, fungi, and microorganisms contribute organic matter and help mix the soil. For example, earthworms aerate soil and break down organic materials.
- R – Relief (Topography): The shape and slope of the land affect drainage, erosion, and how soil accumulates. Steep slopes lose soil to erosion, while flat areas allow soil to build up.
- P – Parent Material: The mineral and organic base from which soil develops, such as bedrock, volcanic ash, or river sediments, affects soil texture, composition, and nutrient availability.
- T – Time: Soil formation is a slow process. It can take hundreds to thousands of years for soil to fully develop, with older soils generally being deeper and more weathered.
300
How are Global Warming and Climate Change different?
Global Warming: Long-term increase in Earth's average surface temperature, primarily caused by human activities and greenhouse gas emissions
- Climate Change: Broader term that includes global warming plus other changes in weather patterns, seasons, precipitation, and extreme events
300
Who was Alfred Wagner?
Created the theory of continental drift. Was widely not accepted at the time
300
What is Seafloor Spreading?
The process by which new oceanic crust is formed at mid-ocean ridges and slowly moves away from them, leading to the movement of tectonic plates.
400
What is Radiometric dating?
Uses the decay of radioactive isotopes to calculate age
400
What is an isotope?
Variants of an element with the same number of protons but different numbers of neutrons.
400
What are all the Climate Proxies (NOT including continental coastal sediments)?
Natural records that help us understand past climates:
- Tree rings
- Ice cores
- Pollen
- Fossils
- Varves (sediment layers)
- Foraminifera (marine organisms)
400
Who was Marie Tharp?
Studied the ocean floor and analyzed data which proved Wagner’s theory and discovered plate tectonics.
400
What are all 5 of the Earth's systems (_spheres)?
Atmosphere (Air)
- Gas layer surrounding Earth
- Composition: 78% Nitrogen, 21% Oxygen, 0.93% Argon, 0.04% Carbon Dioxide
- Functions: Temperature regulation, heat distribution, radiation protection
2. Hydrosphere (Water)
- All water on Earth
- Functions: Heat absorption/storage, water cycle, climate regulation
3. Cryosphere (Ice)
- All frozen water
- Important for albedo effect (reflection of solar radiation)
4. Biosphere (Life)
- All living things
- Affects climate through photosynthesis and respiration
5. Lithosphere (Stone)
- Earth's outer solid layer
- Influences climate through volcanic activity and carbon storage
500
What are all the types of Rock, how do they form, & what is 1 example of each?
Igneous Rocks
- Formed from the cooling and solidification of molten rock
- Two main types:
* Intrusive: Slow cooling beneath Earth's surface (e.g., granite)
* Extrusive: Rapid cooling on Earth's surface (e.g., basalt)
Sedimentary Rocks
- Formed by the accumulation and compaction of particles
- Key formation stages:
* Weathering
* Erosion
* Deposition
* Compaction and Cementation
- Examples: Sandstone, limestone
Metamorphic Rocks
- Created by altering existing rocks through heat, pressure, and chemical changes
- Process involves:
* High temperature and pressure
* Mineral recrystallization
- Examples: Marble, schist
500
What are each of the soil horizons?
500
Which of the following Climate Proxies goes the farthest back in time? - Ice Cores, Tree Rings, Coral Reefs, or Continental Coastal Sediments?
Continental Coastal Sediments
500
Who was Walter Pitman?
Geologist who discovered how the Earth’s magnetic field affects the rocks.
500
What did Walter Pitman Discover?
Magnetic anomalies aligned symmetrically about the axis of the mid-ocean ridge due to the Earth's Magnetic field shifting polarity:
