Rock Classification Answer Key Template (Page 2 of 3) in pdf

Rock Classification Answer Key Template Page 2

Activity A:

Get the Gizmo ready:

Classifying rocks

• Click Reset.

Introduction: You can classify rocks by examining characteristics such as texture. A rock’s

texture is determined by the sizes, shapes, and positions of the grains that make up the rock.

Goal: Classify rocks as igneous, sedimentary, or metamorphic.

1. Summarize: The three groups of rocks each have unique characteristics. For example,

many igneous rocks have a texture of interlocking mineral crystals. Sedimentary rocks may

have distinct layers of sediments, known as strata.

To learn other characteristics of igneous, metamorphic, and sedimentary rocks, turn on

Show common characteristics in the CHARACTERISTICS pane. In the table below,

summarize the textures that will allow you to identify and classify these rock types.

Rock type

Characteristics

Interlocking texture of grains. May display two different grain sizes.

Igneous

Usually dark-colored and dense. Some have vesicles (holes). Composed

of crystals.

Grains cemented together. May show presence of fossils. Usually light-

Sedimentary

colored and low density. Often show layers or bands.

Interlocking texture of large grains. Often show foliation (layering).

Metamorphic

Sometimes show bands of light and dark colors.

2. Classify: Select Name on the SIMULATION pane. Move your cursor over the rock pictures.

Based on what you see, classify the rocks by dragging them into the correct box on the

CHARACTERISTICS tab. Record your classifications (in pencil) in the table below.

Rock type

Rock names

Igneous

basalt, gabbro, granite, pumice

Sedimentary

conglomerate, limestone, sandstone, siltstone

Metamorphic

gneiss, marble, schist, slate

Click on Status to check your answers. If necessary, change your classifications of rocks on

the Gizmo, and make any needed corrections to the table above. When you are done, click

COPY SCREEN to take a screenshot, and then paste the image into a blank document.

Rock Classification Answer Key Template Page 2