Earth's Story
What is uniformitarianism?
The principle that states that geologic change is gradual
How are rock layers usually arranged if they are undisturbed
older beneath younger
what does radioactive mean
unstable isotopes
What is an isotope
an atom with the same number of protons but a different number of neutrons
the study of fossils and past life
paleontology
Why did people reject uniformitarianism?
It suggested that earth was old
The phrase 'younger on top of older' could be used to remember the principle of what
superposition
what is half life
the amount of time it takes for half of the parent material to decay into daughter material
How many protons does sodium have
11
what type of unconformity is shown (image 2)
disconformity
The name of the theory that explains how earth has been shaped over time by sudden events
catastrophism
ideal sequence of rock layers that contain all known fossils and rock formations on earth
geologic column
what happens during radioactive decay
radioactive isotopes break down into stable isotopes of the same or other elements
How many neutrons does Beryllium have
5
erosion is one of the major causes of missing rock layers know as what
unconformities
The person who first proposed that earth has been shaped by slow and gradual over time
James Hutton
what is relative dating
determining the age of objects or events in relation to other objects or events
to figure out the absolute age of a rock you would need what?
the rate of decay for a radioactive element in the rock
What does the atomic number tell us
The number of protons and the number of electrons
what type of unconformity do you see (image 4)
angular unconformity
Who wrote Principles of Geology and agreed with James Hutton's theory
Charles Lyell
what are the four forces that can disturb rock layers
fault, folding, tilting, intrusion
two
what particles do you find in the nucleus of the atom
protons and neutrons
what two factors most commonly cause unconformities
erosion and nondeposition