Devils Tower National Monument

Devils Tower National Monument

Detailed Description

This view shows the large rubble blocks that make up the talus apron around the base of Devils Tower. The tower consists of mostly a dark igneous rock called phonolite, being coarsely porphyritic (bearing crystals including both mafic and feldspar minerals) in a fine (aphanitic) olive-gray groundmass. Much of it has a welded breccia texture (Karner and Halvorson, 1987).


Image Dimensions: 800 x 596

Date Taken:

Location Taken: US