After traveling through northern California in the spring of 1851, two gold prospectors reported seeing an erupting volcano that “threw up fire to a terrible height.” They further claimed that they walked 10 miles over rocks so hot that their boots were entirely destroyed. Their story is only one of several reports from that time that were later assumed to describe an eruption of “Cinder Cone,” a volcanic feature located in what is now the northeast corner of Lassen Volcanic National Park. 

Cinder Cone in Lassen Volcanic National Park is a 700-foot-high volcanic cone. Its age has been controversial since the 1870’s, when many people thought it was only a few decades old. Later, the cone and associated lava flows were thought to have formed about A.D. 1700 or during a 300-year long series of eruptions ending in 1851. However, recent studies by U.S. Geological Survey (USGS) scientists, working in cooperation with the National Park Service to better understand volcano hazards in the Lassen area, have firmly established that Cinder Cone was formed in eruptions about 1650.

Cinder cone volcanoes are built by gaseous lava particles violently ejected high into the air from a single vent, similar to a popcorn popper. The lava shatters into small fragments that solidify in the air and fall as cinders around the vent. As the cinders accumulate, they pile up to form a circular or oval shaped cone. Cinders, more properly known as scoria, are made of a low density basalt that has a bubbly or vesicular texture. As the lava cools quickly in the air, gases are trapped within the rock, creating this texture. Similar to pumice, some cinders will float. Most cinder cone volcanoes have bowl shaped craters at the summit and lava flows are commonly emitted from their bases.

Credits and Sources:

“Volcanoes of Lassen,” National Park Service,http://www.nps.gov/lavo/learn/nature/upload/Volcanoes-site-bulletin.pdf, (Accessed on June 29, 2015.)