<P> As with most other volcanoes in the Cascade Range , Mount St. Helens is a large eruptive cone consisting of lava rock interlayered with ash , pumice , and other deposits . The mountain includes layers of basalt and andesite through which several domes of dacite lava have erupted . The largest of the dacite domes formed the previous summit , and off its northern flank sat the smaller Goat Rocks dome . Both were destroyed in the 1980 eruption . </P>
<P> As with most other volcanoes in the Cascade Range , Mount St. Helens is a large eruptive cone consisting of lava rock interlayered with ash , pumice , and other deposits . The mountain includes layers of basalt and andesite through which several domes of dacite lava have erupted . The largest of the dacite domes formed the previous summit , and off its northern flank sat the smaller Goat Rocks dome . Both were destroyed in the 1980 eruption . </P>
what type of lava did mt st helens have
what type of lava did mt st helens have
dacite lava
dacite lava