Download Day 48

Day 48
What is differential erosion?
When a mountain or plateau is made of
both weak and strong rock, the weak rock
wears away and the strong rock remains.
What is correlation?
The process of finding connections
between rock layers from different
locations.
http://www.youtube.com/watch?v=SP8aesT_RRc
Daily Warm-Up Exercises
1
Reading Grand Canyon Rocks
(Part 4)
Investigation 5
Limestone
2
Colorado Plateau Rocks
You have now examined most of the rocks
that can be seen in the walls of the Grand
Canyon.
Where else can you see many of these
rocks?
at other locations on the Colorado Plateau
How were most of the rocks of the Colorado
Plateau formed?
Layers of sediment piled up on top of
each other and hardened to form rock.
3
Interpreting Environments
What are some clues in a rock layer that
can tell us about the environment in
which it was formed?
type of fossils, particles, crossbedding
http://walrus.wr.usgs.gov/seds/bedforms/animation.html
http://www.youtube.com/watch?v=lUdNMzi0UDw
What is a fossil?
the remains or trace of an organism
preserved in Earth's crust
4
Key to the Past
What is uniformitarianism?
The idea that the present is the key to the
past. Geologists observe modern
environments and compare what they see
to evidence they find in rocks.
5
Environments
Turn to Grand Canyon Environments
(pages 42-43 in the lab notebook).
These pages include notes taken by a
geologist who studied the Grand Canyon.
Your task is to complete the "Environmental
Interpretations" column.
View slide show: Modern Environments
6
Temple Butte
You may have noticed that there is a new
layer on this sheet called Temple Butte.
Temple Butte is not a continuous layer. It
occurs only in certain locations.
How do you think Temple Butte was
formed?
7
Types of Environments
• Marine: Aquatic animals, limestone, shells.
• Beach: Evidence of sand, ripple marks.
• Coastal: Ripple marks, smooth sand, well
sorted.
• Swamp or floodplain: Lots of plants, trails of
animals like worms, snails.
• Desert or sand dunes: Evidence of reptiles,
well sorted sand.
Daily Warm-Up Exercises
8