Rocks 6.1, 6.2, 6.4

Tamika goes hiking and sees an interesting rock formation. The formation looks like it has many different layers. This is an illustration of the kinds of rocks that scientists would discover in each layer if they were to study the formation that Tamika sees. What category of rock is shown in the illustration?

• conglomerate

• igneous

• metamorphic

• sedimentary

Ben is starting a rock collection. He makes a section for igneous rocks. Which of these pairs of rocks should be labeled as igneous rocks?

• conglomerate and marble

• granite and gabbro

• limestone and shale

• quartzite and gneiss

Tamika creates a visual display for her science project on metamorphic rocks. She draws this diagram to show how metamorphic rock is formed. What natural forces cause rocks to change into metamorphic rocks?

• heat and pressure from the magma

• pressure from above and heat from the magma

• pressure and weathering in the layers above the rock

• transportation and heat in the layers below the rock

The rock cycle explains the change of one form of rock into another. Look at the diagram of the rock cycle. When does the rock cycle come to an end?

• The cycle ends when sedimentary rock forms.

• The cycle continues and never comes to an end.

• The cycle ends when weathering grinds down rock.

• The cycle is not a constant process, but only takes place occasionally.

Sheila is classifying the rocks in her collection. She knows that limestone often contains fossils. In which category of rock should she classify these rocks?

• granite

• igneous

• metamorphic

• sedimentary

Karen's mom buys a pumice stone at the store. She uses it to smooth rough patches of skin on her feet. She accidentally dropped the pumice in her bath water and was surprised to see the stone float. Why does this kind of rock float?

• It is formed from quartz sands

• It contains sediment from fish scales

• It is a rock that has lots of gas bubbles or air-filled chambers in it.

• It is a metamorphic rock that is very lightweight.

Eric uses a hand lens to look closely at the surface of a piece of granite. He notices large crystals in the rock that glitter in the sunlight. What is Eric probably seeing?

• fossil fragments

• minerals

• large crystals

• sediment

Mount St. Helens, located in southwest Washington State, erupted on May 18th, 1980. The lava from this eruption had temperatures near 660 °F. formed when the lava quickly cools?

• conglomerate

• igneous

• metamorphic

• sedimentary

May Ling is examining a piece of limestone with a hand lens. She knows that sedimentary rock has many properties. Which is a property of sedimentary rock?

• It contains no minerals.

• It is made of many layers.

• It is made from magma or cooled lava.

• It is made from the bacteria of live and dead plants.

Derrick is examining a piece of obsidian with a hand lens. He knows that igneous rock has many properties. Which is a property of igneous rock?

• It is always very soft

• It is always formed when molten rock cools

• It is made of crushed animal shells, bone, and teeth

• It forms when heat and pressure change other rocks