Students investigate the influence of magma viscosity on the shape of a volcanic cone. Then, they explore nature and motions of lava flows and learn about the importance of lava flows as the building blocks of Mount Rainier. Students will: How do lava flows influence volcano structure and type, specifically at Mount Rainier, Mount St. Helens, and Kilauea? Background Lava flows-building blocks of Mount Rainier Mount Rainier consists of hundreds of overlapping lava flow layers. Sandwiched between the lava flows are layers of loose rock rubble. These lava flows formed during hundreds of individua Duration: 60 Minutes.