Area-Depth Strain Analysis Overview

Area-Depth Strain Analysis is a valuable way to study structures that either

  • sole out into an underlying detachment which is parallel to regional stratigraphy (depth to detachment method),

    Watch Niger Delta Area-Depth Example

  • form above a fault that cuts across the deep bedding (Fault Trajectory Method)

    Mapping Fault Shapes with Area-Depth

    Mapping Fault Shapes using the Fault Trajectory Method in StructureSolver



The technique works by analyzing the variation of excess structural area with depth.   Under appropriate circumstances, this approach results in:

  • A determination of the depth of the controlling detachment, or the location and dip of the controlling fault
  • Estimates of the displacements along the detachment or controlling fault for both pre-growh and growth horizons
  • Estimates of the layer-parallel strain for all horizons.

Area-depth strain analysis in StructureSolver is a valuable tool for interpretation and review of interpretations:

  • area-depth strain analysis is not dependent on any assumptions such as constant bed length or bed thickness.
  • It can be performed before the interpretation is completed.
  • The area-depth strain analysis implementation in StructureSolver can be used easily and quickly for continuous quality control during the interpretation process to catch problems before they become costly mistakes.

Area-depth graphs can be created rapidly in StructureSolver  for any interpretation satisfying these minimum conditions:

  • At least two horizons have been interpreted across the structure(s) of interest.
  • At least two of the horizons should be pre-growth horizons.
  • In the case of the Depth-to-Detachment Method, the horizons should have returned to regional structural levels at both ends of the interpretation.
  • In the case of the Fault Trajectory method, the horizons at both the footwall and and hangingwall ends of the structure should have returned to horizontal.

As in all StructureSolver features, results are dynamically updated if any changes are made to the interpretation.

Results from Area-depth graphs can be compared to results from structural modeling and restorations performed in StructureSolver. Since each method is independent, consistent results from all three indicate that the interpretations are robust.