Rocks

A class has an igneous rock in their rock collection. Where did this rock most likely form?

• In a volcano

• On a coral reef On a forest floor D. At the bottom of a river

• On a forest floor

• At the bottom of a river

Which of the following rock samples contains fossils?

• Obsidian

• Pumice

• Granite

• Limestone

Limestone has tiny grains arranged in layers, feels gritty  reddish tan or gray, and has a fish fossil

Obsidian looks like black glass, cannot see parts of other things, and feels smooth.

Pumice is light gray, has tiny holes like a sponge, very lightweight, and feels very rough.

Granite has tiny specks that are black, white and gray  specks are about the same size.

Sedimentary rocks have small pieces of other rocks in layers that you can see. Based on the above, which is a sedimentary rock?

• A. Limestone

• B. Obsidian

• C. Pumice

• D. Granite

Gneiss, slate, and schist are types of rocks that were formed from other rocks. These three rocks are examples of ____.

• fossil rocks

• igneous rocks

• sedimentary rocks

• metamorphic rocks

Granite and basalt are common igneous rocks of the Earth. Igneous rocks are formed when rock material is _____.

• cooled and hardened

• heated and deposited

• heated and pressed together

• pressed down with other rocks

Soil is made of _____.

• A. glass, sand, and rocks

• B. humus, clay, and sand

• C. glass, water, and minerals

• D. water, minerals, and rocks

Marble and slate are metamorphic rocks. What process could have created these rocks?

• erosion

• pressure

• weathering

• evaporation

Which is part of the soil that contains decayed parts of a once living organism?

• silt

• clay

• sand

• humus

Which is the following correctly describes the thick layer of topsoil?

• It has lots of clay.

• It is rich in humus.

• It does not contain minerals.

• It is not good for growing plants.

After using a sieve to separate a sample of soil, students noticed a fine powder left over in the bottom container. This fine powder was most likely _____.

• silt

• loam

• tiny organisms

• pieces of the screen