Igneous Rocks and Their Properties

The video, part of the 'Rocks with Willsey' series, focuses on igneous rocks, specifically andesite, dacite, and rhyolite. It explains their formation, texture, and mineral composition, highlighting the differences between extrusive and intrusive rocks. The video also discusses the types of volcanoes associated with these rocks, such as lava domes and calderas. Samples of each rock type are shown, emphasizing their unique characteristics. The session concludes with a preview of the next topic: sedimentary rocks.

What type of rocks are Granite, Granodiorite, Diorite, and Gabbro?

• Intrusive Igneous

• Sedimentary

• Metamorphic

• Extrusive Igneous

Which of the following textures indicates that a rock is extrusive?

• Phaneritic

• Gneissic

• Aphanitic

• Granular

What are vesicles in igneous rocks?

• Large crystals

• Gas bubbles

• Mineral inclusions

• Fossils

Which type of volcano is most likely to produce andesite?

• Fissure eruption

• Stratovolcano

• Cinder cone

• Shield volcano

What is the primary mineral composition of andesite?

• Mica and Quartz

• Olivine and Pyroxene

• Plagioclase Feldspar, Pyroxene, and Amphibole

• Quartz and Feldspar

Which mineral is more abundant in dacite compared to andesite?

• Olivine

• Amphibole

• Quartz

• Pyroxene

What is the typical color of rhyolite?

• Black

• Light gray to pinkish

• Dark gray

• Greenish

Which volcanic feature is commonly associated with rhyolite?

• Shield volcano

• Cinder cone

• Fissure eruption

• Caldera

What texture is commonly found in rhyolite?

• Gneissic

• Aphanitic

• Phaneritic

• Granular

Which of the following rocks is the most silica-rich?

• Andesite

• Rhyolite

• Basalt

• Dacite