1. Calculate the composition of a rock (or magma if melted) made of 10% of Olivine, 30% of Clinopyroxene, and 60% of Plagioclase ( 24% of Anorthite, 24% of Albite, and 12% of Orthoclase) from the composition of its minerals.

2. What is the name of the rock in question 1 if it is fine-grained? See Handout 7.

3. Calculate the composition of 40 kg of melt (magma) that could be derived by partially melting 100 kg of the rock of the composition you calculated in question 1. The rock left after partial melting consists of 10 kg of Olivine, 20 kg of Clinopyroxene, 24 kg of Anorthite, and 6 kg of Albite.

4. What is the name of a fine-grained rock that could crystallize from the magma in question 3? See Handout 7.

5. Calculate the densities of the two magmas (from question 1 and 3), based on the densities of oxides.

6. Estimate the difference in height between a column filled with the magma you calculated in question 1 (magma #1) and the magma you calculated in 2 (magma #2) if they are in isostatic equilibrium and the height of the magma #1 is 100 km.
   Check your answer ONLINE. Enter it here: km
   ( You can limit precision to one digit after decimal point )
7. Search the WWW for the difference in elevation of the Pacific seafloor and Mt. Fuji in Japan. See hint.

8. Discuss the relevance of your answer to question 6 with your data in question 7.