Oregon State University geophysicist Adam Schultz and co-authors believe they may have solved the mystery of why Mount St. Helens, a volcano located in Skamania County, in the State of Washington, is located outside the main line of the Cascade Arc of volcanoes. They think that the Spirit Lake batholith, a subsurface rock formation some 20-30 miles (32-48 km) in diameter, diverted magma and partially melted rock outside of the arc and to the west,...
