Yellowstone Caldera Chronicles is a weekly column written by scientists and collaborators of the Yellowstone Volcano Observatory. This week’s contribution is from Lisa Morgan, emeritus research geologist with the U.S. Geological Survey.
This color-shaded relief topographic map of the track of the Yellowstone hotspot shows the ages and locations of volcanic fields and faulting patterns which become younger to the northeast. Areas in cooler colors (greens and blues) represent low topographic elevations, whereas warmer colors (oranges and reds) represent high elevations.
Pierce and Morgan, 1990 USGS
The youngest part of the Yellowstone hotspot left a trail of volcanic products that begins in northern Nevada and southern Oregon about 17 million years ago, with the volcanic rocks becoming younger as the track stretches across southern Idaho to Yellowstone National Park. The volcanic rocks are the products of ancient eruptions from systems that looked very much like the Yellowstone Caldera does today. These “ancient Yellowstones” are now buried, so how were they recognized by geologists? How was the Yellowstone hotspot track identified?
Like most scientific advances, the answer builds on a long history