3-D Structural Interpretation: Earth, Mind, and Machine

Three-dimensional geologic interpretation of surface and subsurface data requires integration and application of both geologic knowledge and spatial cognitive skills. Much surface geologic mapping still employs pen and paper techniques, but subsurface interpretation is usually accomplished using sophisticated visualization software. In both cases, successful interpreters use mental models that bridge internal and external forms of 3-D visualization to construct 3-D geologic interpretations. This AAPG Memoir 111 sets out to understand more about the convergence of geology, 3-D thinking, and software, which collectively provide the basis for truly effective interpretation strategies. It should appeal to all geologic interpreters, and especially those who investigate and teach interpretation skills.
Insight on Mechanical Stratigraphy and Subsurface Interpretation
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Published:January 01, 2016
Abstract
A valid structural geologic interpretation should simultaneously honor available surface and subsurface data (e.g., well and seismic) to constrain structural geometry; ideally be restorable to an original unstrained condition – taking into account the possibility of three-dimensional (3-D) movement, volume loss, or volume gain; and incorporate structural styles known or expected for the mechanical stratigraphy and deformation conditions in the region. Incorporating what is known about the mechanical stratigraphy can provide crucial constraints on viable structural styles, for example, where faults are likely to cut across stratigraphy vs. where fault displacement is likely to be accommodated by alternative mechanisms (e.g., ductile flow or folding). Conversely, the structural style can often help to understand the mechanical stratigraphy, including the recognition of dominant competent or incompetent mechanical stratigraphic units. Using this approach provides the interpreter another set of constraints toward improving interpretations, testing hypotheses, and developing valid structural interpretations.
Outcrop characterization provides insights into the influence of mechanical stratigraphy and structural position on seismic- and subseismic-scale deformation in the layers. Examples of extensional deformation in Cretaceous carbonate strata in central and west Texas illustrate the utility of considering how mechanical stratigraphy influences the development of different deformation styles, even where deformation conditions are otherwise similar.
- Bexar County Texas
- Brewster County Texas
- brittle deformation
- characterization
- Comal County Texas
- Cretaceous
- deformation
- displacements
- ductile deformation
- extension tectonics
- faults
- geometry
- geophysical methods
- geophysical profiles
- geophysical surveys
- Gulfian
- interpretation
- Mesozoic
- outcrops
- San Antonio Texas
- secondary structures
- sedimentary structures
- seismic methods
- seismic profiles
- stratigraphy
- stylolites
- surveys
- tectonics
- Texas
- three-dimensional models
- United States
- Upper Cretaceous
- West Texas
- central Texas
- Boquillas Formation
- Big Brushy Canyon
- Canyon Lake Gorge
- Beckmann Quarry
- Black Gap Management Area