Ground view of black scoria outcropping in tephra deposits along the west shore of South Killeak Lake. South Killeak Lake is one of the Espenberg maars, enormous volcanic craters formed by the explosive interaction of magma with water from permafrost. Note the light-colored rock fragments strewn within the tephra deposit. These are pieces of the sedimentary rocks ripped up from the underlying bedrock during violent explosive activity.
Location:Latitude: 66.337455555556
Longitude: -164.13743611111