Chapter 8: Earth History
The idea that the same geological process that happens today has been around forever. Uniformitarianism is believed by many scientist.
is the idea that geologic change happens suddenly
The meteor hitting the earth was a huge catastrophism
The study of plant and animal fossils.
Through the study of paleontology we have learned many things about plants. relative dating:
Relative dating is a way to determine the age of a fossil.
Relative dating was used in the findings of many fossils.
rock formed from consolidated clay sediments.
Sedimentary rocks are found all over the world.
Involves rocks and there ages. Which one is older and which is not. The scientist used superposition to determine which layers of rocks came first. unconformity:
a break in the geologic record created when rock layers are eroded or when sediment is not deposited for a long period of time Unconformities can be split into two using the law of crosscutting relationships. Crosscutting relationships
the principle that a fault or body of rock is younger than any other body of rock that it cuts through An example of the law of crosscutting relationships would be when a fault splits. absolute dating:
any method of measuring the age of an event or object in years There are many different methods used in absolute dating.
the spontaneous disintegration of a radioactive substance along with the emission of ionizing radiation. radiometric dating
a method of determining the age of an object
Radiometric dating is an intricate technique to determine the age of a particular thing. half-life
the time required for something to fall to half its initial value (in particular, the time for half the atoms in a radioactive substance... The elimination half-life varies from about 1 to 4 hours.