Earth History Flashcards
1
Q
Relative Age
A
age compared to something else
2
Q
Absolute Age
A
Exact Age
3
Q
Isotope
A
Variety of an element
4
Q
Radioactive Decay
A
unstable elements change to become stable
5
Q
Half Life
A
time it takes for half to decay
6
Q
Uniformitarianism
A
processes have not changed through time
7
Q
Original Horizontality
A
sediments are laid down flat first
8
Q
Superposition
A
old on bottom, young on top
9
Q
Cross-Cutting Relationship
A
something that cuts thru is always
younger
10
Q
Inclusion
A
old rock pieces stuck in magma
11
Q
Unconformity
A
buried erosional surface
12
Q
Key Bed
A
unique layer in the rocks
13
Q
Correlation
A
Matching
14
Q
Intrusion
A
magma pushes thru & stays in
15
Q
Extrusion
A
magma/lava pushes thru & comes out
