Because Iceland is part of the mid-ocean ridge, its composition is primarily basaltic, as would be expected of new oceanic crust. Based on your reading of the article and Essentials of Geology, explain why the magma encountered in the drilling was instead a rhyolite, which is more typical of continental crust. (Hint: what is the influence of partial melting on the magma composition

Iceland lies very close to the ridge and rocks melt due to the competition of magma.

Explanation:

As Iceland forms a part of the mid-ocean ridge, it's composed mainly of the basaltic lava and the new oceanic crust is formed underneath this layer of crust as new lava spreads in both the sides if the mid-oceanic crust.  The particle melting of the solid rocks is controlled by the three features of temperature, pressure, and composition. These generate the magma and decompress the melting, the rocks melt slowly and gradually and there is a change in volume.