Rock Types
These rocks form when magma or lava cools and solidifies.
What are igneous rocks?
This term describes the time it takes for half of a radioactive sample to decay.
What is half-life?
This is the largest division of geologic time shown on the reference table.
What is an eon?
Oxygen was first released during this process.
What is photosynthesis?
This process breaks rocks into smaller pieces without changing their composition.
What is weathering?
After one half-life, this percentage of the original radioactive atoms remains.
What is (50%)?
The first land plants appear during this era.
What is the Paleozoic Era?
This event caused oxygen levels to rise dramatically about 2.4 billion years ago.
What is the Great Oxidation Event?
This model shows how rocks change from one type to another over time.
What is the rock cycle?
This radioactive element is commonly used to date rocks that are as old as the Earth.
What is Uranium-238?
This era is known as the “Age of Dinosaurs.”
What is the Mesozoic Era?
Oxygen reacts with iron to form this type of rock found in ancient layers.
What is banded iron formation?
Name two processes that can turn igneous rock into sedimentary rock.
Weathering, erosion, deposition, compaction & cementation
A Carbon-14 sample has 12.5% remaining. How many half-lives have passed?
What is three half-lives?
Put events in order from oldest to youngest
1) SILURIAN
2) CAMBRIAN
3) TRIASSIC
4) DEVONIAN
2) CAMBRIAN-OLDEST
1) SILURIAN
4) DEVONIAN
3) TRIASSIC- YOUNGEST
This type of organism was the first to release oxygen into the atmosphere.
What are cyanobacteria?
Granite is an example of this type of igneous rock.
What is intrusive igneous rock?
Explain why Carbon-14 dating cannot be used on igneous rocks.
Rocks were never living and do not contain Carbon-14.
What time period did Trilobites go extinct
What is the Triassic Time Period
Explain how the Great Oxidation Event changed life on Earth.
It caused extinctions of anaerobic life and allowed aerobic life to evolve.