Fossils
What is a fossil?
Remains of ancient organisms.
What is a rock layer?
A distinct layer of rock
What does the geologic time scale show?
Earth's history divided into time periods.
What does original horizontality mean?
What is a stratigraphic column?
A diagram of rock layers.
What is an index fossil?
A fossil that indicates a specific time period.
What is the principle of superposition?
Name one era on the geologic time scale.
Paleozoic, Mesozoic, or Cenozoic.
What is the principle of inclusions?
Older rocks can be found in newer rocks
How do geologists determine the order of rock layers?
Name one type of fossil.
Dinosaur bone or leaf imprint.
What can you learn from rock layers?
They show Earth's history and past life.
What is the difference between an era and a period?
An era contains multiple periods.
Describe how rock layers are deposited.
They form over time from sediment.
Why are sedimentary rocks important in stratigraphy?
They provide a record of Earth's history and past life.
How do fossils form?
They form when organisms are buried quickly.
Explain lateral continuity. (the spread)
Layers spread out in all directions.
How is the geologic time scale divided?
Divided into eons, eras, periods, and epochs.
What is erosion?
The process of removing soil and rock.
What is the significance of studying rock layers?
They help understand geological events and timelines.
Why are fossils important?
They help us learn about past life and environments.
How do we determine the age of rock layers?
By studying fossils and using dating methods.
Why is the geologic time scale important?
Helps understand Earth's history.
Explain the concept of relative age.
It affects how we date the layers.
How can changes in rock layers indicate past environmental conditions?
Changes can show shifts in climate, sea levels, or ecosystems.