Alkalic Complexes Colorado Geological Survey
Alkalic Complexes. Alkalic complexes in Colorado''s Wet Mountains and the Powderhorn district near Gunnison, Colorado contain carbonatite and a variety of other exotic rock types. Both complexes contain abundant rare earth elements. Indeed, Powderhorn (also known as Iron Hill) contains the nation''s largest volumetric deposit of rare earths as well as the world''s largest titanium deposits.