anwers the cross-world puzzle to learn more about the formation and composition of magma across 1 the second abundant element present in magma 3 formed in the upper mantle with low silica content 6.gas present in magma in large a mount. 8 a rise in__cause the minerals to melt 9 rocks or minerals containing water are heated down 2.formed when oceanic crust subducted into mantle 4 molten rocks underneath 5.happens when no water and carbon dioxide in them 7.it increases the rocks melting point ​