Theories to explain
the past
“I believe that the more you
know about the past, the better
you are prepared for the future.”
-Theodore Roosevelt
Theories to explain the past
These theories will be used for the foundation of this Ancient Origins course.
Catastrophism: Georges Cuvier
The theory that the Earth has been affected in the past by sudden, short-lived, violent
events, possibly worldwide in scope.
Modern Interpretation (Modern catastrophism)
The theory that evidence from catastrophic forces can have a major influence on shaping
Earth. Example: Asteroid collision
Uniformitarianism : James Hutton
A contrast to catastrophism (sometimes described as gradualism), in which slow
incremental changes, such as erosion, created all the Earth's geological features.
Creationism: Bishop James Usher
The belief that the Universe and Life originate "from specific acts of divine creation." For
young Earth creationists, this includes a biblical literalist interpretation of the Genesis
creation narrative and the rejection of the scientific theory of evolution.
Superposition: Charles Lyell
Older is lower! The lower strata contents will be older than those in strata near the
surface.
Three Age Theory: Christian Thomsen
Every culture goes through three ages unless disturbed by a more advanced culture.
Ages= Stone, Bronze & Iron
3:00
Catastrophism: Georges Cuvier
anthro.palomar.edu
www.ancient-wisdom.com
http://bareket-astro.com/en/project/asteroid.files/image008.jpg
Catastrophism -- Past Cataclysmic Activity
Catastrophism is the idea that many of Earth’s
crustal features (strata layers, erosion, polystrate
fossils, etc.) formed as a result of past
cataclysmic activity. In other words, the Earth’s
surface has been scarred by catastrophic natural
disasters.
Cuvier stated that different groups of fossil organisms were created
and then became extinct as the result of geologic catastrophes, the
last of which was the Great Flood described in the Bible. Each
catastrophe, according to Cuvier, killed the fossilized organisms and
deposited the sediment that solidified into the rock surrounding
the fossils.
Modern Interpretation
(Modern catastrophism)
Armageddon (3:02)
gencept.com
www.dinosaurfact.net
Twentieth century catastrophism, often called neocatastrophism, is
founded entirely in science, relying solely on natural forces for its
explanations. The argument states that these collisions have major
effects on the geology and biology of Earth.
www.britannica.com
Uniformitarianism:
The present is the key to the past
Erosion (Example)
2:26
www.f21.org.au
Theories of Geological Evolution
Superposition
Older is lower!
The lower strata contents will be older than those in strata near the
surface. Basically, rock layers can accumulate over time.
Superposition (6:00)
This particular theory is an
amazing example of a good
theory. It’s predictive,
parsimonious (simple) and
powerful!
Creationism
Creationism is the belief that the earth and universe and the
various kinds of animals and plants were created by God or gods.
Creationism is primarily based on: the Bible’s account which
includes the idea that man is created in the image of God. This
theory plays a major part in the belief system of Western
Civilization.
Three Age Theory: Christian Thomsen
Every culture goes through three ages unless disturbed by a more
advanced culture. Ages= Stone, Bronze & Iron
BACKSTORY: During the 1800s many
educated, wealthy young European men
scattered around the globe, collecting
artifacts from all corners. Some items were
purchased, stolen, or dug up from
archaeological sites. Many items ended up in
museums.
The curators of these museums were faced
with displaying them in some manner.
Thomsen sorted the museum's objects by the
material culture, resulting in separate rooms
for Stone Age, Bronze Age and Iron Age. He
suggested that the order was probably
chronological; a fact established later by
archaeologist J.A.A. Worsaae.
For the first time, excavators began
paying attention to layers or strata,
in archaeological deposits.
Applying the
Principle of
Uniformitarianism
Processes that happen today happened in
the past with the same results.
In other words, the present is the key to
the past.
What does
thisthis
mean:
"The present
key to the
What
does
mean:
“ Theis the
present
ispast"?
the key to the past”?
How can this photo help you to figure out what happened in Earth's history? You see
the molten lava. You see what the rock looks like when the lava cools. What if you see
that type of rock in an outcrop? You can assume that it formed from molten lava. This is
the best tool for understanding Earth history. Earth scientists use what they know about
Earth in the present to figure out what happened in the past.
HOW DID THIS ROCK FORM?
This is at Checkerboard Mesa in Zion National Park, Utah.
Notice the very interesting pattern on it.
If you look carefully at the rock, you will
see that it’s made of sand. This rock
formation is called the Navajo sandstone.
Does knowing that the rock is sandstone
tell you how it formed?
No, although it limits the
possibilities. The next thing to do is
to make observations now and
apply them to this rock that formed
long ago.
Uniformitarianism
James Hutton came up with this idea in the late 1700s.
The present is the key to the past.
He called this the principle of uniformitarianism. It works like
this: we understand a geological process that happens now. We
see the outcome of that process, say a rock. Then we find
evidence that same process happened in the past, like a similar
rock. We can assume that the process operated the same way
in the past.
Let’s think again about Checkboard Mesa... What would cause
sandstone to have layers that cross each other, a feature called
cross-bedding?
Answer: EARTH HISTORY
DINOSAUR RIDGE
Use the media clip resource to answer the following questions in your
history spiral notebook.
1. How does a geologist use observations about how and where ripple
marks are found to understand ripple marks in a rock?
2. What do the colors of the rocks tell us?
3. Explain the principle of uniformitarianism.
Dinosaur Ridge
3:40
LET’S WRAP IT UP!!
You may need to apply what you know about the present
to determine what happened in the past.
If you see something forming by a process today and then
find the end results of that process in the rock record, you
can assume that the process operated the same way in the
past.