Sedimentological Processes Modeling Christopher G. St.C. Kendall
Outline of Presentation • Data - Outcrops, well log & seismic cross sections • Sequence stratigraphy & modeling • Relative sea level & 2D/3D sedimentary simulations • Inverse conceptual simulation models versus numerical forward modeling • Short-term, high-resolution, local versus long-term basin wide • Holocene data particularly carbonates • Sedimentary simulation movies & modeling. Interconnected modules of numerical process simulations of sedimentary basins evolution - the future
Sequence Stratigraphy History • 1791 - William Smith established relationship of sedimentary rocks to geologic time • 1962 - Hess proposed the theory of sea-floor spreading • 1963 - Vine & Matthews identified deep ocean paleomagnetic "stripes“ • 1965 - Wilson began developing the theory of plate tectonics • 1977 - Vail proposed the discipline of sequence stratigraphy
Types of Simulations Sedimentary modeling: • Carbonates vs. clastics • Stochastic vs. deterministic • Fuzzy vs. empirical • Small vs large oceanic basins
Traditional Use of Sedimentary Simulations Sedimentary process models fromoutcrops, well log & seismic cross sections used to: • Understand complexities of clastic or carbonate stratigraphy • Identify & model sedimentary systems. • Quantify models that explain & predict stratal geometries within sequences. • Used by specialized experts who design & build the simulations.
Sedimentological Processes Modeling 2D & 3D sedimentary simulations, relative sea level, physical processes, & sedimentation & erosion: • Inverse conceptual simulation models • Numerical forward modeling advanced. • Short-term, high-resolution local events vs a long-term regional events
Approaches to modeling Geometric models • Fixed depositional geometries are assumed • Conservation of mass • Simple computations through general nonlinear dynamic models • Variations in depositional geometries • Variations in surface slope vs discharge • More complex computationally Chris Paola, 2002
Some sedimentary models • Short-term local events • SEDSIM (Tetzlaff and Harbaugh, 1989) • SEDFLUX (Syvitski et al., 1998a; Syvitski et al., 1998b) • Long-term regional events • PHIL (Bowman et al 1999) • SEDPAK(Eberli, et al, 1994) • FUZZIM(Nordlund1999a&b) • CSM (Syvitski et al., 2002) • Robinson and Slingerland, 1998 • Steckler et al., 1993.
Geometric Model • Ross et al., 1995 • Jervey, 1988 • Perlmutter et al., 1998 Chris Paola
Geometric Models “Jurassic Tank” Chris Paola, 2002.
Geometric Model Eberli, et al, 1994
Uses by Specialized Users • John W. Harbaugh 3D sedimentary fill • Carey et al., model high-resolution sequence stratigraphy • Bowman & Vail empirical stratigraphic interpretion - stratigraphy of the Baltimore Canyon • Kendall et al.,empirical stratigraphic simulator for Bahamas • Syvitski et al., model links fluvial discharge, suspended sediment plume, associated turbidites, the effects of slope stability, debris flow, and downslope diffusion
Approaches to modeling Geometric models • Aigner - Deterministic 2D • Bosence et al. - 3D Forward & Fieldwork • Bosscher - 2D Forward Model • Bowman - Forward Model • Cowell - Shoreface Model • Cross and Duan - 3D Forward Model • Demicco - Fuzzy Modeling
Some of the carbonate modelers • Aigner - Deterministic 2D • Bosence et al. - 3D Forward & Fieldwork • Bosscher - 2D Forward Model • Bowman - Forward Model • Cowell - Shoreface Model • Cross and Duan - 3D Forward Model • Demicco - Fuzzy Modeling
Further carbonate modelers! • Flemmings - Meter-scale shaoling cycles • Goldhammer - High-frequency platform carbonate cycles • Granjeon - Diffusion-based stratigraphic model • Kendall – Deterministic forward model • Ulf Nordlund - Fuzzy logic • Read - Two-dimensional modeling • Rivanaes - Depth-dependent diffusion models of erosion, transport & sedimentation
Why limited use of simulations • Software integrates seismic, well logs, outcrops & current depositional systems • On site interpretations & evalutation of data revealing origin of sediment depositional systems • Models explain sedimentary geometries displayed on interpreted seismic & well log sections
Data Sources Historically sedimentary modeling derived from real data • Seismic • Wells. • Outcrop But less from: • Holocene
Outcrops King 1954
Simulation Data Needs • Models are commonly based on subsurface • Input variables known but values are inferred from geologic record • Need to refine observations at deposition • Complexity needs to be handled by a team approach Need to gather data from a Holocene setting like the “Arabian Gulf”
Regional Drainage Into Basin Restricted Entrance To Sea Isolated linear Belt of interior drainage Arid Tropics Air System Wide Envelope of surrounding continents
Arid Climate United Arab Emirate Coast Barrier Island Coast Coastal Evaporite System Reef Platform Aeolian System
Tidal Deltas United Arab Emirate Coast Arid Climate Coastal Evaporite System Reef & Lagoon
Power of Simulation Movies Annotated movies of sedimentary simulation show evolution of sedimentary geometries in response to variations in rates of: • Sedimentation • Tectonic movement • Sea-level position Movies involve hypothetical & real-life examples based on outcrops, well log & seismic cross sections.