STRUCTURAL GEOLOGY IN THE WORKSTATION ERA: WHERE MIGHT IT GO?

The 1st question of structural geology, “what is it?” must be answered correctly before the 2nd question, “why is it?” can be properly addressed (Dahlstrom, 1970). Traditional structural geology answers the 1st question on a flat surface (e.g., paper) with the third dimension being in the mind of the beholder. In what might be called “GIS” structural geology, the question is answered on a 3-D surface. In “workstation” structural geology, the answer is a 3-D volume. Workstation mapping answers the 1st question better than ever before, enabling us to turn our concepts into digital reality. Would it not be wonderful to have a universal 3-D Structural Operating System (SOS) in which to perform and render volume interpretations? It should be 1) free (or cheap), 2) simple (as possible), and 3) accept the popular proprietary data formats. In addition to providing an interpretation environment, an SOS would allow the exchange of interpretations just like in the good old paper-copy days. Some 1st-question research issues suggest themselves. Is there a simple way to build constant-bed-thickness interpretations in 3-D? Is mapping axial surfaces in 3-D the best interpolation-extrapolation strategy? Can structures with variable displacement be balanced and restored in 3-D? Would it not be wonderful to have a catalog of type-example structures as 3-D volumes, including both laboratory models and field examples? There is also a dark side to workstation interpretation, because of the illusion that pushing the “map tops” button produces a correctly interpreted structure. Mapping 3-D seismic has analogous problems. Most U.S. students go into industry when they graduate and will have had only a single course in structural geology. Does this give them the structural background necessary to evaluate their own workstation work? Educational priorities in the workstation era might differ from those of the traditional era. Exciting opportunities abound.