Superposition
According to this law, the oldest rock layers are found in this position.
What is at the bottom
This form of age dating tells you the actual number of years something has existed.
What is absolute age?
When an organism leaves a hollow space in sediment, this type of fossil is created.
What is a mold?
This is the longest unit of geologic time.
What is an eon?
Organisms that lived for a short, specific period of time, and are easily recognizable.
States that sedimentary rock layers are initially deposited as horizontal layers, parallel to the Earth’s surface.
What is ORIGINAL HORIZONTALITY
This term describes age in comparison, not exact numbers.
What is relative age?
When tree sap hardens around small organisms, this type of fossil results.
What are Preserved remains
Mammals became the dominant life-form during this era.
What is the Cenozoic?
Fossils the create mineral copies of the organisms shape.
Disturbances like faults or intrusions are always __________ than the layers they cut through.
What is Younger
Using Radiometric data to determine the age of a sample is referred to as.
What is Absolute Age
Fossilized evidence that animals have left are examples of.
What is Trace Fossils
What era ended with the "great dying"?
What is the Paleozoic?
Pieces of older rock stuck in younger layers.
What is Principle of Inclusions?
A gap in the geologic record when rock layers are missing.
What is UNCONFORMITIES
“Layer A is older than Layer B” is an example of this type of age measurement.
What is relative dating?
What is it called when parts of the original remains are replaced or filled with rocks and minerals?
The formation of Earth and earliest life occurred during this eon.
What is the Precambrian
Angular indicates lilted layers were eroded before new layers were deposited?
What is a Angular Unconformity?
States that rock layers start extending horizontally in all directions.
What is PRINCIPLE OF LATERAL CONTINUITY
The ratio between parent and daughter isotopes is used to find this time measurement.
What is the half-life?
What are the two key components to fossilization?
What is Rapid burial and low oxygen levels?
Major time boundaries on the geologic time scale are often marked by these dramatic events.
What are mass extinctions?
A thin layer of carbon residue left behind after an organism is compressed.
What is a Carbon Film?