Vocab 1
The principle of ____________ states that geologic processes that happened in the past can be explained by current geologic processes.
Uniformitarianism
radioactive decay
No, it was never a living organism
What is the difference between relative and absolute dating
relative dating is if something is older or younger
absolute dating is its actual age
What is another name for radioactive isotopes
________ are the trace or remains of an organism that lived long ago.
Fossils
The law of _________ is the principle that states younger rocks lie above older rocks if the layers have not been disturbed.
Superposition
What are 2 ways that scientists study earths climate history
Ice, trees, sea-floor sediments
How are sedimentary rock layers deposited
horizontally
What is another name for stable isotope
daughter isotope
A ______ _________ is a fossilized structure that formed in sedimentary rock by animal activity
trace fossil
An __________ is a break in the geologic record.
Unconformity
What are 3 examples of Trace fossils
animal dung, burrows, footprints
What are crosscutting relationships
That an intrusion or fault must be younger than the rocks they go through.
If a radioactive isotope has a 1/2 life of 10 years. And 1/2 of the radioactive isotopes have turned into stable isotopes, how old is the sample
10 years
ice core
A _____ _________ is an ordered arrangement of rock layers that is based on the relative ages of the rocks.
Geologic Column
How do we know that the continents have moved
We see fossils from the same animals on two different continents
What are geologic columns used for
To compare rocks from two different locations.
How do sedimentary rock show earth's history
Composition, Texture, Features
_____ is the scientific study of the origin, history, and structure of Earth and the processes that shape it.
Geology
_______ is the time needed for half of a sample of a radioactive substance to undergo radioactive decay.
Half-life
Name the 5 ways that fossils can be preserved
trapped in amber, trapped in asphalt, buried in rock, become frozen, Become petrified
What are the 5 ways rock layers can be disturbed
folding, faulting, tilting, intrusions, unconformity
If we find tropical plant fossils in Antarctica what does that tell us.
Antarctica used to have a tropical climate of wet and hot rather than cold