Sheehan Lesson 4

Proposed Earth changes either rapidly or gradually

Re-introduced uniformintarism

Living organisms adapted to their environment as Earth changes

C: Violent, destructive, slow
U: Slow, gradual

C: Slow, gradual
U: Violent, destructive, rapid

A: Determining relative order of past events without knowing exact age
R: Accurately determining the age of a material using isotopes

A: Determining accurate age of material
R: Determining relative order of past events without knowing exact age

Tilting, folding, faulting

Intrusions, folding, tilting

The youngest fossil is located towards the top, but not always

The Earth is 4.6 billion years old because of observations