Minerals and Rocks

What are the layers of sedimentary rocks called?

• foliated bands

• strata

• crystallization

Answer explanation

The layers of sedimentary rocks are called strata. This term refers to the distinct layers formed by the accumulation of sediments over time, distinguishing them from other rock types like foliated bands or processes like crystallization.

Tags

NGSS.MS-ESS1-4

__________ is when rock is broken down by water, wind, ice or heat.

• weathering

• erosion

• foliation

• compaction

Answer explanation

Weathering is the process where rocks are broken down by natural forces like water, wind, ice, or heat. This distinguishes it from erosion, which involves the movement of these broken materials.

Tags

NGSS.MS-ESS2-2

What is molten rock called inside the earth?

• magma

• lava

Answer explanation

Molten rock inside the Earth is called magma. When it erupts onto the surface, it is referred to as lava. Therefore, the correct answer is magma.

__________ describes igneous rock that is dark in color because it does not have much silica.

• intrusive

• felsic

• mafic

• extrusive

Answer explanation

Mafic describes igneous rock that is dark in color due to its low silica content. In contrast, felsic rocks are lighter in color and have higher silica levels. Therefore, the correct answer is mafic.

How are rocks classified?

• by their texture

• by their mineral composition

• by how they were formed

Answer explanation

Rocks are classified primarily by how they were formed: igneous, sedimentary, or metamorphic. While texture and mineral composition are important, the formation process is the key criterion for classification.

Lava that cools quickly has ________ texture.

• course

• large

• mafic

• fine

Answer explanation

Lava that cools quickly forms a fine texture due to rapid solidification, resulting in small crystals. In contrast, slower cooling allows for larger crystals, making 'fine' the correct choice.

Tags

NGSS.MS-PS1-4

________ igneous rock forms when magma cools beneath Earth's surface.

• organic

• extrusive

• intrusive

Answer explanation

Intrusive igneous rock forms when magma cools slowly beneath Earth's surface, allowing large crystals to develop. In contrast, extrusive rock forms from lava that cools quickly on the surface.

When lava cools quickly on Earth's surface, what kind of rock is formed?

• organic sedimentary

• extrusive igneous

• intrusive igneous

Answer explanation

When lava cools quickly on Earth's surface, it solidifies rapidly, forming extrusive igneous rock. This type of rock is characterized by its fine-grained texture due to the rapid cooling process.

The process of __________ creates sediment. (hint... sediment is broken rock material)

• weathering

• erosion

• deposition

Answer explanation

The process of weathering breaks down rocks into smaller particles, creating sediment. Erosion involves the movement of sediment, while deposition refers to the laying down of sediment, not its creation.

Rocks that have strata must be...

• igneous

• metamorphic

• sedimentary

Answer explanation

Rocks with strata are formed by the accumulation of sediments over time, which is characteristic of sedimentary rocks. Igneous rocks form from molten material, and metamorphic rocks result from changes in existing rocks, not layering.

Tags

NGSS.MS-ESS1-4