Chapter 27, Problem 19TE

What type of lava erupts at divergent boundaries? What type erupt at convergent boundaries?

To determine

The type of lava erupts at divergent boundaries and the types erupt at convergent boundaries.

Answer to Problem 19TE

Basaltic thin mafic lava erupts at divergent boundaries and is due to Shield volcanoes, while composite volcanoes are common along convergent plate boundaries and erupt thick felsic lava.

Explanation of Solution

The volcanic eruptions are found at divergent plate boundaries when there is a distinction between the continents.

The basic difference between the magma and the lava is that magma is the hot molten material that evolves inside the Earth while the lava evolves on the surface of Earth.

The lava evolves on the surface of Earth cools quickly and solidifies as compared to the magma that evolves inside the Earth and takes time to cool and solidify.

The mafic lava produced in the shield volcanoes is observed often along with the divergent plate boundaries which are non-explosive too. In contrast, the lava produced at the convergent boundaries is felsic.

Conclusion:

Therefore, Basaltic thin mafic lava erupts at divergent boundaries and is due to Shield volcanoes, while composite volcanoes are common along convergent plate boundaries and erupt thick felsic lava.