1. (a) What is the average temperature of Earth’s interior 20 km below the surface? (b) How much warmer is it 30 km below the surface compared to 10 km below? 2. A geologist finds an igneous rock that...

1. (a) What is the average temperature of Earth’s interior 20 km below the surface? (b) How much warmer is it 30 km below the surface compared to 10 km below?

2. A geologist finds an igneous rock that has large crystals embedded in a matrix of smaller crystals. What is the texture of this rock? How did it form?