September 1997

Medicine Lake Volcano, in northern California, was chosen as a collection site for its diversity of lava types, and also because a young obsidian lava flow called Glass Mountain erupted there only 850 years ago. Shiny black and nearly crystal free, obsidian is a dramatic example of the processes that occur within volcanoes. Ro Kinzler also collected samples of the many cinder cones and of basalt lava, the most common lava type at Medicine Lake.  

A view from Little Mount Hoffman, a peak on Medicine Lake Volcano, looking to the northwest. In the foreground is a lava flow called little glass mountain. Mount Shasta looms in the background.

photo credit: Jackie Beckett, © American Museum of Natural History