On the Road to Mount St. Helens
August 11, 2017
The photo above was taken along the road to Mount St. Helens (Washington State) and shows evidence of volcanic activity well before the well-documented 1980 eruption. This lava flow (slab at top) covers an underlying assortment of pyroclastic rocks in varying stratifications. Mount St. Helens, a composite volcano, erupted for the first time 40-50,000 years ago. Composite volcanoes have steep sides and are made up of layers of lava, ash and other types of volcanic materials. When they erupt, they do so much more explosively than gently sloping volcanoes, such as Mauna Loa in Hawaii. Photo taken on June 19, 2017.