CATASTROPHISM AND
UNIFORMITARIANISM
Processes that change Earth’s Surface
CATASTROPHISM
 Formation of Earth
… series of large, violent, quick, worldwide upheavals
changed the earth greatly and produced
mountains, valleys, and various other large scale
features
 In changing Earth’s surface
… once in a while, sudden and widespread
catastrophes would hit the planet and wipe out a
number of species.
… These catastrophes were natural events, like
volcanoes, earthquakes, and floods, and they
would also change Earth’s landscape.
MT. ST. HELENS
 Mt. St. Helens
… http://www.youtube.com/watch?v=hNTeOjo5Cvs
JAPAN TSUNAMI
INDONESIAN EARTHQUAKE/TSUNAMI
UNIFORMITARIANISM
 Formation of Earth
… Geologists found that features of Earth changed slowly over
long periods of time, they called it gradualism, also known as
uniformitarianism.
… gradual processes (such as for example the slow erosion of
the coast by the impact of waves) shaped the geologic record
of the earth over an immensely long period of time
 In changing Earth’s surface
… the acting processes were the same as those that we see in
action at present (rivers, volcanoes, waves, tides etc.)
… extremely rare (and catastrophic) events, such as the impact
of large meteors, may have had a profound influence on our
planet.
EXIT SLIP
 Give a three word description of
uniformitarianism.
 Give a three word description of
catastrophism.
 How do these geoscience processes
change Earth’s surface over time?
QUOTE #1
“All geological formations from
the mountains, to the
thousands of feet of rock
beneath your feet, to the coal
and oil deposits in the ground
were all formed slowly over
millions of years of gradual
sedimentary deposition.”
QUOTE #2
“ Throughout its formation, the
earth was battered, heated,
cooled and scarred. Through the
experience of continuous natural
disasters, the earth took its
present day shape and form.
QUOTE #3
“The present is the key
to understanding the
past”
QUOTE #4
“Slow, gradual, natural
events transpiring today
occurred just like this in
the past in the formation
of the structures of the
earth.”
QUOTE #5
“Earth appears the way it
does because of sudden,
large-scale major ordeals
that have sculpted it’s
features quickly through
cataclysmic events.”