1 trilobite hunter, part 1 introduction to the grand canyon earth history, investigation 8
Post on 16-Jan-2016
213 Views
Preview:
TRANSCRIPT
1
Trilobite Hunter, Part 1
Introduction to the Grand CanyonEarth History, Investigation 8
2
Rock Hunt
Imagine you are on a field trip to a local quarry with your school. The teacher asks everybody to find the coolest rock they can and bring it back to her.
You and your friend go to opposite sides of the quarry. You both find rocks at the same time and you wave to each other.
3
You bring back a grey rock with marks on it that look like a picture of a bug.
Your friend brings back a weird rock that hardly weighs anything and is full of tiny holes.
Two Rocks
4
Your teacher says,“That’s a trilobite fossil. You can sell that on the internet for a lot of money.”
Your friend says, “I want one too. Where should I look?”
Trilobite Fossil
The teacher answers, “If you want to find fossils, you have to know how rocks form and what kinds of rock have fossils in them.”
5
Throughout this module, see if you can figure out the answers to these questions:
Questions
What kinds of rocks are likely to contain fossils?
Where should you look for trilobite fossils?
6
There are some places where it's easy to find lots of different kinds of rocks.
The tallest mountains and deepest canyons are both great places to look.
The Grand Canyon is a really great place to look, because you can see rock layers there that represent millions of years of Earth's history.
Where to Look
7
Your friend's rock is called pumice.
Pumice
Let’s go find some pumice in the Grand Canyon and see if we can figure out why your friend's rock doesn't have a trilobite fossil.
Compare Rock Types 8
Compare Rock Types
Contrasting Case Activity 1, Part 1Earth History, Investigation 8
Compare Rock Types 9
Venn DiagramSimilarities. Rocks of the same type have some things in common.
Differences. Rocks of the same type can also be different from each other.
These things
are only true
about the first
rock
These things
are true about both rocks
These things
are only true
aboutthe
second rock
Compare Rock Types 10
How to use a Hand Lens
Hold the hand lens so the big circle is very close to your eye. Bring the rock closer and closer to the lens until it pops into focus.
Try the same thing with the smaller circles. The magnification is stronger, but you can only see part of the rock at a time.
Holding the lens close to your eye will take full advantage of its magnifying power.
What does this word mean?
Compare Rock Types 11
List Observable Features
What do the rocks look like?
How do they feel?
Create a table in your lab notebook and list the features you can observe about the two igneous rock samples.
Igneous #11
Igneous #17
Compare Rock Types 12
Which is Which?
Can you figure out which rock is granite and which is pumice?
11
17
11
17
Compare Rock Types 13
What’s the same?
Look at the two cards.
Are any of the points exactly the same for both rocks?
How would you show this in the diagram?
Compare Rock Types 14
Igneous
Granite OnlyBoth Granite &
PumicePumice Only
Formed when molten rock cools and hardens
11
17
Compare Rock Types 15
What else is the same?
Are any of the points partly the same for both rocks?
How would you show this in the diagram?
Compare Rock Types 16
Igneous
Granite Only Both Granite & Pumice
Pumice Only
Formed when molten rock cools and hardens
Rough and dull
Compare Rock Types 17
What is different?
Identify one thing that is true about granite but not about pumice.
How would you show this in the diagram?
11
17
Compare Rock Types 18
Igneous
Granite Only Both Granite & Pumice
Pumice Only
Made of minerals
Formed when molten rock cools and hardens
Rough and dull
It is hard and has shiny, smooth crystals
Most grains are coarse
Usually fairly light in color
Formed deep beneath Earth’s surface
Compare Rock Types 19
What else is different?
Identify one thing that is true about pumice but not about granite.
How would you show this in the diagram?
11
17
Compare Rock Types 20
Igneous
Granite Only Both Granite & Pumice
Pumice Only
Grain size is fine to medium
Contains a lot of small air pockets
Usually feels lighter than other rocks of its size
Formed on Earth’s surface from molten rock released by a volcano
Made of minerals
Formed when molten rock cools and hardens
Rough and dull
It is hard and has shiny, smooth crystals
Most grains are coarse
Usually fairly light in color
Formed deep beneath Earth’s surface
Made of volcanic glass
top related