Wet Mountains

An alkaline province in the northern Wet Mountains of Colorado includes three central complexes together with extensive swarms of carbonatitic and alkaline dykes and thorite veins (Armbrustmacher, 1984a). The central complexes of McClure Mountain-Iron Mountain (No. 89), Gem Park (No. 90) and Democrat Creek (No. 91), together with the carbonatite occurrences of Amethyst (No. 85), Goldie (No. 87) and McCoy Gulch (No. 88) are described individually, as is the breccia pipe at Pinon Peak (No. 86). The distribution of the carbonatite dyke swarm is shown on Fig. 156 and these rocks have been described by Armbrustmacher (1979), who divides them into replacement and primary magmatic types using petrographic criteria. Both calcite and dolomite occur and magnesite has been identified. A considerable number of accessory minerals have been found, with the greater variety in the primary magmatic carbonatites. The lamprophyric dykes have been described by Heinrich and Dahlem (1970).