Law of Superposition Vocab

Question 1

Uniformitarianism

Define and who created it

Answer 1

principal the states the same geological processes shaping the Earth today have been at work throughout Earth’s history.
(Erosion: ice, wind, water, gravity)

James Hutton 1795

Question 2

Catastrophism

Answer 2

all geological changes occur suddenly

Natural disasters: earthquakes, volcanos, mudslides

Question 3

Intrusion

Answer 3

When magma cools beneath Earth’s surface

Question 4

Extrusion

Answer 4

When magma cools on Earth’s surface

Question 5

Folding

Answer 5

Stress and pressure cause rocks to deform and fold.

Question 6

Faulting

Answer 6

When rocks break apart; crack

Question 7

Tilting

Also where they occur

Answer 7

When forces cause rock to tilt

angular unconformities

Question 8

Index Fossil

Answer 8

Fossil that defines and identifies geological periods; often found in 1 rock layer

• easily recognizable
• widely distributed
• exist over short geological time range

Question 9

Relative Dating

Answer 9

Finding the relative age of rock by examining its position in a rock layer and comparing it to something else.

Question 10

Law of Superposition

Answer 10

For undisturbed rock: oldest layer on bottom

youngest on top

Question 11

Charles Lyles

What did he do and what book did he write and when?

Answer 11

Challenged catastrophism and argued changes are gradual

Principals of Geology, 1880

Question 12

Geologic Time Scale

Answer 12

Time intervals that divide Earth’s history