Unit 4: Rocks, Minerals, and Weathering

Which type of rock is formed when magma or lava cools and solidifies?

• Igneous rock

• Granite

• Metamorphic rock

• Sedimentary rock

Answer explanation

Igneous rock is formed when magma or lava cools and solidifies. Granite is a type of igneous rock, while metamorphic and sedimentary rocks are formed through different processes.

Which type of rocks are created when other rocks are changed through heat and/or pressure?

• Igneous rocks

• Metamorphic rocks

• Sedimentary rocks

• Volcanic rocks

Answer explanation

Metamorphic rocks are formed when existing rocks undergo changes due to heat and pressure. This process alters their mineral composition and structure, distinguishing them from igneous and sedimentary rocks.

How are sedimentary rocks formed?

• Sedimentary rocks are formed from the accumulation and lithification of sediment.

• Sedimentary rocks are formed through the process of metamorphism.

• Sedimentary rocks are formed by the cooling of magma.

• Sedimentary rocks are formed from volcanic activity.

Answer explanation

Sedimentary rocks are formed from the accumulation and lithification of sediment, which involves the compaction and cementation of particles over time. This distinguishes them from metamorphic and igneous rocks.

Which of the following minerals is a silicate?

• Calcite (CaCO₃)

• Gypsum (CaSO₄)

• Halite (NaCl)

• Quartz (SiO₂)

Answer explanation

Quartz (SiO2) is a silicate mineral, composed of silicon and oxygen. In contrast, calcite (CaCO3), gypsum (CaSO4), and halite (NaCl) are not silicates, as they contain different chemical compositions.

What type of rock is pictured?

• Extrusive Igneous Rock

• Foliated Metamorphic Rock

• Nonfoliated Metamorphic Rock

• Sedimentary Rock

Answer explanation

The rock is classified as a Foliated Metamorphic Rock due to its layered appearance, which results from the alignment of minerals under pressure. This distinguishes it from other rock types listed.

the science that deals with the dynamics and physical history of the Earth, the rocks of which it is composed, and the physical, chemical, and biological changes that the Earth has undergone or is undergoing

Answer explanation

The question describes the study of the Earth's physical history, rocks, and changes, which is the definition of geology. Therefore, the correct answer is geology.

Rocks consist of one or more _____________________.

Answer explanation

Rocks consist of one or more minerals. Minerals are naturally occurring, inorganic solids with a definite chemical composition and crystalline structure, making them the fundamental building blocks of rocks.

Which type of sedimentary rock is composed of compacted broken rocks?

• Clastic

• Organic

• non-clastic

• chemical

Answer explanation

Clastic sedimentary rocks are formed from the compaction of broken fragments of other rocks. This distinguishes them from organic, non-clastic, and chemical sedimentary rocks, which have different formation processes.

Rocks form the Earth's ______________________.

• crust

• mantle

• core

• atmosphere

Answer explanation

Rocks primarily make up the Earth's crust, which is the outermost layer of the planet. The mantle and core are deeper layers, while the atmosphere is the layer of gases surrounding Earth. Thus, the correct answer is crust.

Which of the following are types of igneous rocks? Check ALL that apply.

• plutonic

• intrusive

• extrusive

• foliated

• volcanic

Answer explanation

Igneous rocks are classified into types based on their formation. Plutonic and intrusive rocks form below the Earth's surface, while extrusive and volcanic rocks form from lava on the surface. Foliated is not an igneous type.