Igneous Rocks Quiz

What is the main characteristic of igneous rocks that makes them resistant to physical weathering and erosion?

• Interlocking crystals of minerals

• High iron content

• High water content

• Organic composition

What is the basic structure of silicate minerals in igneous rocks?

• Tightly bonded units of carbon and hydrogen

• Tightly bonded units of nitrogen and sulfur

• Tightly bonded units of calcium and magnesium

• Tightly bonded units of silicon and oxygen

What is the difference in crystal size between igneous rocks that cool slowly and those that cool rapidly?

• Slow cooling results in fine-grained texture, while rapid cooling results in coarse-grained texture

• Slow cooling results in coarse-grained texture, while rapid cooling results in fine-grained texture

• Slow cooling results in frothy texture, while rapid cooling results in glassy texture

• Slow cooling results in glassy texture, while rapid cooling results in frothy texture

Which mineral composition results in light-colored igneous rocks?

• Gabbro, basalt, and peridotite

• Plagioclase feldspar, biotite mica, and obsidian

• Quartz, potassium feldspar, and muscovite mica

• Pyroxenes, amphiboles, and olivines

Where are igneous rocks with high percentages of quartz, potassium feldspar, and muscovite mica commonly found?

• In oceanic crust

• Where lithospheric plates are spreading apart

• At mid-ocean spreading ridges

• Where lithospheric plates are moving together

What causes some magmas to have a high content of dissolved gases, leading to explosive volcanic eruptions?

• High carbon dioxide content

• High-silica content

• High water content

• High iron content

What type of igneous rock is formed when magma cools and solidifies beneath the Earth's surface?

• Extrusive igneous rock

• Intrusive igneous rock

• Sedimentary rock

• Metamorphic rock

What type of igneous rock is formed when magma cools and solidifies above the Earth's surface?

• Extrusive igneous rock

• Intrusive igneous rock

• Sedimentary rock

• Metamorphic rock