Abstract
• Introduction
• General Remarks on Bedforms in Open Bedrock Channels
• Terminology and Definitions
• Introduction
• Erosion Mechanisms
• A Definition of Bedforms in Open Bedrock Channels
• Describing the Effect of Rock Structure on Channel Morphology
• Structural versus Hydrodynamic Control of Morphology
• Structurally Influenced Channel Morphologies
• Further Definitions
• Simple, Compound, and Coalesced Forms
• Isolate and Conjugate Forms
• Sharp or Cuspate Edges
• Flutes and Scallops
• Furrows, Grooves, Runnels, Troughs, Welts, and Channels
• Potholes
• A Typology of Bedrock Bedforms
• Introduction
• 1. Concave Features
• 1.1 Potholes
• 1.2 Longitudinal Furrows
• 1.3 Nonlongitudinal Furrows
• 1.4 Furrow Complexes
• 1.5 Overhanging Concave Features
• 1.6 Shallow Concave Surfaces
• 2. Convex and Undulating Surfaces
• 2.1 Hummocky Forms
• 2.2 Other Convex and Undulating Surfaces
• 3. Composite Forms
• 3.1 Obstacle Marks
• 3.2 Hummocky Forms with Linear Depressions
• 3.3 Convex Surfaces with Steep Lee Faces
• 4. Solutional Forms
• 4.1 Solution Pits and Pans
• 4.2 Scallops
• 4.3 Other Solutional Forms
• 5. Tool Marks
• 5.1 Percussion Marks
• 5.2 Scratch Marks
• 6. Large-Scale Sculpted Features
• 6.1 Uniform Bed Gradient
• 6.2 Variable Bed Gradient
• Further Observations and Discussion
• Principles Applying to the Morphology of Bedrock Bedforms
• 1. Continuity of Form
• 2. Convergence of Form
• 3. The Constructive Interference of the Flow Structures of Contiguous Bedforms
• 4. The Prevalence of Sharp Transverse Crests
• The Origin of Two Types of Sharp-Crested Transverse Features
• Sharp-Crested Hummocky Forms and Scallops: A Comparison
• The Origin of Scallops
• The Evolution of Directional Scallop Planforms
• The Origin of Sharp-Crested Hummocky Forms
• The Development of Sharp Edges in General
• The Phenomenon of Sharp Edges in Bedrock Bedforms
• A Criterion for the Development of Sharp Edges
• Types of Sharp Edges
• Mean Flow Pathlines Associated with Active Sharp Edges
• Further Comments on the Interpretation of Bedforms in Open Bedrock Channels
• Bedforms as Indicators of Flow Patterns
• Bedforms as Indicators of the Relative Roles of Bedload and Suspended Load in Erosion
• The Relative Importance of Erosion by Suspended Load and Bedload: A Hypothesis
• The Influence of Substrate on Bedform Development in Open Bedrock Channels
• Bedforms in Carbonate Rocks
• Bedforms in Silicate Rocks
• The Scale of Bedforms in Open Bedrock Channels
• Conclusions
• Acknowledgments
• References Cited