California's volcanoes formed as the result of what type of plate boundary?
California's volcanoes formed as a result of colliding boundaries.
The volcanoes in California formed as a result of the plate boundary known as a "convergent boundary." To explain how I arrived at this answer, let me break it down for you.
To determine the type of plate boundary, we need to examine the tectonic plates involved in the region. In the case of California, we have the Pacific Plate and the North American Plate. These two plates are converging, which means they are moving towards each other.
Convergent boundaries can take different forms, but in California's case, we have what's known as a "subduction zone." This occurs when an oceanic plate, in this case, the Pacific Plate, is forced beneath a continental plate, which is the North American Plate.
As the denser oceanic plate slides beneath the continental plate, it generates intense heat and pressure. As a result, the descending oceanic plate begins to melt, forming magma. The magma then rises through the overlying plate, eventually reaching the surface as volcanoes.
This process has given rise to notable volcanic features in California, such as the Cascade Range in the north (including Lassen Peak and Mount Shasta) and the Trans-Mexican Volcanic Belt in the south (including Mount St. Helens and Mount Rainier).
In conclusion, the volcanoes in California formed as a result of the convergent boundary between the Pacific Plate and the North American Plate, specifically through the process of subduction.