Fossils Flashcards
What are traces or remains of living things from long ago?
fossils
What is a way to show the changes in climate in cold areas?
ice cores
What type of rock do we see fossils?
sedimentary
What states that the forces changing the Earth today are the same forces that changed Earth in the past?
Theory of Uniformitarianism
What do scientists use to figure out absolute age of unknown organisms?
radioactive dating
What element is commonly used in radioactive dating?
carbon
What is the amount of time for the amount of something to fall to half its initial value?
Half life
What is commonly used to find the relative age of an unknown organism?
index fossils
What states, in layers of undisturbed rocks, the oldest layer will be on the bottom and the youngest layer will be on the top?
Principle of Superposition
Where does an igneous intrusion come from?
Inside the Earth
Where does an igneous extrusion come from?
Volcanic eruption
What is a gap in geologic time?
unconformity
What is the main cause of unconformities?
erosion
