The principle of uniformitarianism

Uniformitarionism is a principle that
states that the same geologic processes
shaping the earth.
Uniformitarianism Versus
catastrophism …
•
•
Catastrophism is a principle that states
that all geologic change occurs suddenly
Supporters of catastrophism claimed
that the formation of all Earth’s features,
such as it’s mountains, canyons, and
seas, could be explained by rare, sudden
events called catastrophes.
Uniformitarianism Wins!

Despite Hutton’s observations,
catastrophism remained geology’s
guiding principle for decades.
Relative Dating
Which come first
 Relative dating – Determine whether an
object or an event is older or youngest
than other object or events.

The principle of superposition

Superposition- is a principle that state
that younger rocks lie above older rocks
in undisturbed sequences.
The geologic column

Geologic column- is an ideal sequence
of rocks layers that contains all the
known fossils and rocks formations on
earth arranged from oldest to youngest.
Types of unconformities
Disconformities- parallel rocks layer is
missing.
 Nonconformity- exists where
sedimentary is.
 Angular unconformity- Exist between
horizontal rock layer and rock layer are
titled or foled.
