Daily Warm-Up Exercises 1

Day 2When someone says a rock has fine grains or coarse grains, what are they talking about?

Grains are the particles that make up a rock. The words fine and coarse refer to the size of the grains. Fine grains are small, and coarse grains are larger.

What is molten rock?Molten rock is melted rock.

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Trilobite Hunter, Part 2

Introduction to the Grand CanyonEarth History, Investigation 8

3

Return to Trilobite HunterAre igneous rocks good for finding trilobite fossils?

No, because they are made of molten rock, which is much too hot to preserve organisms.

granite pumice

4

Return to Trilobite Hunter

We are now going to look at a second type of rock, called metamorphic. We’ll find out if metamorphic rocks are good for finding fossils.

These rocks are found in some of the deepest layers of the Grand Canyon.

5

Compare Rock Types

Contrasting Case Activity 1, Part 2Earth History, Investigation 8

Compare Rock Types

6

List Observable Features

Metamorphic #1

Metamorphic #18

List the features you can observe about the two metamorphic rock samples.

Compare Rock Types

7

Which is Which?

Can you figure out which rock is schist and which is quartzite?

1

18

Compare Rock Types

1

18

8

What’s the Same? What’s Different?

Identify similarities and differences and write them in the Venn diagram.

Compare Rock Types

Compare Rock Types 9

Metamorphic

Schist OnlyBoth Schist & Quartzite Quartzite Only

Fairly shiny

Medium to coarse grain size

Formed from slate, a metamorphic rock

Crystals are flat and arranged in layers

Made of minerals

Formed when a rock changes due to heat and/or pressure

Formed deep beneath Earth’s surface

Dull and hard

Fine grain size

Formed from sandstone, a sedimentary rock

Rough

Grains appear to be fused together

10

Return to Trilobite HunterAre metamorphic rocks good for finding trilobite fossils?

Not very good because the heat and/or pressure will usually destroy any fossils contained in the original rock.

schistquartzite

11

Return to Trilobite Hunter

Let’s look at one more type of rock, sedimentary. We’ll find out if sedimentary rocks are good for finding trilobite fossils.

Compare Rock Types 12

List Observable Features

Sedimentary #7

Sedimentary #8

List the features you can observe about the two sedimentary rock samples.

Compare Rock Types 13

Which is Which?

Can you figure out which rock is shale and which is sandstone?

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8

7

8

14

What’s the Same? What’s Different?

Identify similarities and differences and write them in the Venn diagram.

Compare Rock Types

Compare Rock Types 15

Sedimentary

Shale Only Both Shale & Sandstone

Sandstone Only

Smooth

Very fine grain size

Grains are arranged in layers

Formed from particles of silt or clay

May contain fossils

Made of minerals

Formed when something gets compacted and cemented together

May form on or below Earth’s surface

Rough

Medium to coarse grain size

Formed from grains of sand

Dull and hard