Lava Mountain, Wyoming

Lava Mountain, Wyoming.  (A) View from Dubois, WY, in the Wind River basin looking northwest ~30 km toward Lava Mountain. Yellow line is approximate boundary between Lava Mountain eruptive units (above line) and older Eocene (34-56 million years old) rocks.  Notice how the overall shape of 8-km-wide Lava Mountain resembles a shield volcano, like those in Hawaiʻi.  Arrows mark the top and bottom of well-exposed glacially truncated 230-m-high cliff, where at least 20 lavas crop out in a flow-on-flow stratigraphic context. Photo by Matthew Brueseke, Kansas State University, June 2006, used with permission.  (B) Close-up view of Lava Mountain illustrating the capping scoria cone at the summit and the underlying lava units. These show the volcano underwent at least two phases (effusive and then explosive) of volcanism.  Photo by Matthew Brueseke, Kansas State University, August 2014, used with permission.