Questions/Conclusions 1. Based on what you have learned in this Activity, describe the relationship between volcanoes and plate boundaries? 2. What type(s) of volcanic rock is (are) generally found at divergent plate boundaries? What type(s) of volcanic rock is (are) generally found at convergent plate boundaries? 3. Compare your sketch of plate boundaries to the World Map with Plate Boundaries. How does your map showing volcano locations compare to those on the World Map with Plate Boundaries? 4. Volcanic rocks are often classified based on color, as follows: rhyolite andesite basalt grey, pink dark grey black The color of volcanic rocks is partly related to the proportion of silicon dioxide they contain. Which of the rocks listed on the Data Sheet tend to have the highest proportion of silicon dioxide? The next highest? The lowest? 5. Based on the information provided on the Data Sheet, what generally happens to the proportion of iron oxide (FeO+ Fe2O) in volcanic rock as the level of silicon dioxide (SiO ) increases