Global Volcanism Program | Image GVP-03207
The prominent lava dome of Shastina, seen here on the right from the north, was formed on the west flank of Shasta between about 9500 and 9230 years ago. The summit of Shastina contains several overlapping plug domes. Hotlum cone (left), which forms the summit of Mount Shasta, may overlap Shastina in age, but is mostly younger.
Photo by Dan Dzurisin, 1982 (U.S. Geological Survey).