Slopes

Slope settings are influenced by numerous factors, including sediment bypass, mass wasting, incision by canyons and gullies, and/or widespread suspension settling of fine-grained particulate debris. Significant deposition of coarse-grained detritus may occur on slopes, particularly associated with ponding in channels and minibasins. Ichnology has been underutilized in assessing slope strata, mainly owing to erroneous perceptions that slope trace-fossil suites are (1) relatively homogeneous and exclusively assigned to the Zoophycos Ichnofacies or (2) largely indistinguishable from basin-floor assemblages. Organisms residing on the slope respond to varied parameters such as current energy, sedimentation, slope instability, substrate consistency, oxygen and food availability, and water turbidity, which in turn, are controlled by factors such as basin circulation, water stratification, shelf width, and sediment supply (e.g., point vs. line source). Depending upon the influence of these parameters on a subenvironment, slope trace-fossil suites can be assigned to the Zoophycos, Cruziana, Skolithos, Glossifungites, or Nereites ichnofacies.