1Daily Warm-Up Exercises 1

Day 19What is ice wedging (or frost wedging)?

Ice wedging is a physical weathering process. It happens when water seeps into cracks, then freezes and expands, pushing outward and breaking the rock apart.

What is the difference between weathering and transport?

Weathering is when rocks break apart. Transport is when rock pieces are carried from one place to another.

2

Make Sandstone(Part 5)

Investigation 4

My Sediments Exactly

33

Compare Sand & SandstoneWhat's the same about sand and sandstone?

They're both made up of small particles of rock.

What's different about them?The sandstone is glued together. The sand is loose.

44

MatrixThe material that glues the sand together in sandstone is called a matrix. A matrix is a chemical that glues a rock together.

Several materials can act as the matrix in sandstone.

Today, you will make sandstone using a matrix called sodium silicate.

5

Sodium Silicate• Silicate minerals are found in many kinds of

rocks.

• These minerals may be chemically weathered & dissolved in water.

• Our solution is a mixture of sodium silicate and water.– similar to the the solution found in nature

6

BasinIn the stream table, what happened to the eroded material?

The water carried it downhill and deposited it in a lower area.

Low areas are called basins. You will use a plastic container as your model basin.

Follow the recipe on page 33 to make sandstone.

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Compare Model to RealityWhere would we find large collections of sand?

beaches, sand dunes

How could sodium silicate get between the sand grains?

Water with a lot of dissolved sodium silicate could seep into the sand.

8

Sequence of Events

Just after deposition, sand is loosely packed (lots of space)

Sand is compacted over an extended period of time (very little space)

Water carrying dissolved matrix seeps into the sand

Sand is cemented together by matrix as water evaporates

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QuestionsHow can acid or water soak into sandstone?

There are spaces between grains that can hold liquid.

What type of rock is sandstone?sedimentary

10

Examine & Compare• Use a hand lens to examine your model sandstone.

• Compare your model to Coconino Sandstone. Record similarities and differences. Think about:– the origin of the sand– the matrix that holds the sandstone together– the size and compactness of the sand grains– evidence for your conclusions