Question

1. describe the 3 main textures of igneous rock and how the cooling rate of magma and lava affect the textures:

a. coarse - grained:
b. fine - grained:
c. other igneous rock:

Explanation:

• Coarse - grained: Magma cools slowly beneath the Earth's surface. Larger mineral crystals form as atoms have more time to arrange.
• Fine - grained: Lava cools quickly on the Earth's surface. Smaller mineral crystals form as atoms have less time to arrange.
• Other Igneous rock (e.g., glassy): Some igneous rocks like obsidian form when lava cools extremely rapidly (almost instantly in some cases), preventing crystal formation.

Answer:

a. Coarse - grained: Magma cools slowly (beneath surface), large crystals.
b. Fine - grained: Lava cools quickly (on surface), small crystals.
c. Other Igneous rock: E.g., obsidian (glassy) - lava cools extremely fast (no crystal formation).