Volcanoes are usually found along the boundaries of tectonic plates. Constructive plate boundaries are where tectonic plates are moving apart, and magma here can gradually rise and form new crust ...

Lahars can contain rocks, trees and even houses. They form as rainfall, snow, or melting ice and wash ash deposits off the slopes of volcanoes and into surrounding valleys at high speeds.

but specifically iron-rich extinct volcanoes," Anenburg told Newsweek. The researchers found that the solidified magma that ...