CONSTRAINING THE ORIGIN OF CLIMACTICHNITES FOUND IN FLOAT AND POSSIBLE IMPLICATIONS FOR THE IGNACIO FORMATION, SOUTHWESTERN COLORADO, USA
The lower portion of the Tamarron Member of the Ignacio Formation at Electra Lake is interpreted as a wave and tide influenced shoreline deposit, a facies that is not dissimilar to the tidal flat deposits in which Climactichnites is found. Trace fossils, such as Skolithos, Planolites, and Gordia are common. Poorly preserved phosphatic brachiopods were equivocally identified as Dicellomus, Lingullella, or Obolus. Sericite cement found in the Climactichnites-bearing slab and several lithologically similar samples may be related to a mineralized fracture that crosscuts several beds of the Tamarron Member and contains euhedral barite and weathered sulfides.
No further specimens of Climactichnites were found. However, similarities in lithology, petrographic similarities such as a two-phase diagenetic history, and similarities in depositional environments between the Climactichnites-bearing slab and the Tamarron Member of the Ignacio Formation suggest it is plausible that the fossil may have originated from Electra Lake, and that the Devonian age of the Ignacio Formation may therefore require revision.