Rob Butler and Bill McCaffrey Please pass comments back to: Outline STRUCT-STRAT The linked study of deformation and depositional processes on submarine slopes VIRTUAL SEISMIC ATLAS Knowledge Transfer community initiative School of Earth and Environment University of Leeds

A NEW RESEARCH PROGRAM STRUCT-STRAT The linked study of deformation and depositional processes on submarine slopes Rob Butler and Bill McCaffrey with Martin Casey Outline Background – research at Leeds Outline the scientific challenges Research Program Pathfinder project Consortium project Please pass comments back to: CONFIDENTIAL

Leeds Research Environment School of Earth and Environment (SEE) One of the largest geoscience groups in the UK. Long history of academic and applied research Large research-student community (40+) Unique range of industry-focused taught Masters courses (Geophysics, Structural Geology, Engineering Geology) Links to industry through consortium research and spin- off companies (e.g. RDR)

Leeds Research Environment – key groupings Structure Group 25 years structural research in thrust belts, fold modelling etc. Rob Butler, Martin Casey + 6 PhD students MSc Structural Geology with Geophysics Turbidites Research Group (TRG) 12 years deep marine clastics research Bill McCaffrey plus Rob Butler, Jaco Baas, Jeff Peakall + 8 PhD students + externals Rock Deformation Research (RDR) Leading structural consultancy and applied research group. Rob Knipe et al. Geophysics Group Greg Houseman, Lykke Gemmer and students. Numerical modeling of lithosphere deformation Graham Stuart, Roger Clark et al. Seismics: MSc Geophysics Engineering Geology Group etc Bill Murphy, Lucy Phillip: geotechnical studies, mass wasting. PhD and MSc students – linking with Civil Engineering groups in Leeds + external collaborator: Scott Bowman, President of PetroDynamics Development of PHIL Stratigraphic Modelling package

Leeds Research Environment – investigators Outlines of the key research personnel in the Struct-Strat project. Collectively we have published over 150 research papers and supervised >40 research students. Rob Butler 25 years experience in the structural geometry and evolution of thrust systems. Research has developed to use high resolution stratigraphy to investigate thrust-fold kinematics. Founding director of MSc Structural Geology with Geophysics. Bill McCaffrey Currently Director of TRG. Over 15 years experience of deep marine clastics and application of research to industry. Martin Casey Co-investigator. 30 years experience of numerical structural geology, particularly the use of finite element methods to investigate deformations. Latterly has applied soil mechanical approach to study deformation in poorly consolidated sediments. + External collaborator: Scott Bowman, President of PetroDynamics

A NEW RESEARCH PROGRAM STRUCT-STRAT The linked study of deformation and depositional processes on submarine slopes Rob Butler and Bill McCaffrey with Martin Casey and Scott Bowman Outline UPDATE – FROM POTENTIAL SPONSORS Outline the scientific challenges Research Program Pathfinder project Consortium project

UPDATE – April Following discussions with possible sponsors we would like to draw out the following key themes: 1.Regional aspects – a main driver here is to develop predictions of slope geometries in the past – using these to predict possible sites of preferential sand accumulation. Beneficial for evaluating new prospects within known slope systems – say when seismic data are poor and the system is subsequently deformed, or to examine consequences. 2. Prospect scale – Understanding links between fold-thrust development and nature of strat template may reduce risk in poorly imaged fore-limb areas. 3.All scales – feedbacks between rates of deformation and deposition could have large control on scales/timing/distribution of remobilisation. 4. Relationship with proprietary data. Data are needed – the Pathfinder phase will need to establish nature of release/confidentiality of proprietary data within the consortium (and for publication).

Sediment patterns on slopes. External controls on deep water clastic systems The bathymetric influence on sediment deposition Structural evolution Why? Sed load drives/modifies slope structure Sed style impacts wedge rheology Sed architecture impacts on fault zone evolution Multi-disciplinary project e.g. TRG geometry mechanics Consortium Pathfinder Establish workflows Focus deliverables Develop partnerships

Sedimentation and deformation on submarine slopes Scales … The slope system (wedge dynamics) Individual/groups of folds/thrusts Evolution of fold-thrusts and fault zone architecture Scales … The slope system (wedge dynamics) Individual/groups of folds/thrusts Evolution of fold-thrusts and fault zone architecture deformation styles Deposition/strat architectures OUTLINE OF RESEARCH CHALLENGES

Slope grading processes Deposition of turbidites Shallow-detached MTCs Whole prism creep different stable (“equilibrium”) slopes… Controls 1 – tectonic subsidence (thermal, inversion etc) 2 – sediment load (flexural isostatic) 3 – sediment input (timing, flux, nature) 4 – gravity spreading deformation

Evolution of active submarine slopes: sediment load drives deformation, deformation impacts on sediment distribution. Predict slope-dip and rugosity create synthetic slopes – input to facies distribution models Probabilistic prediction of the distribution and characteristic architectures of sand bodies on deformed submarine slopes. before after

A 2-D finite element model of the system geometry, populated with rheological properties. Differential sediment loading and associated surface slope modification A diffusion-based sediment dispersal model, or proprietary strat-modelling packages. viscousplastic SEDIMENT WEDGE DETACHMENT e.g. mud (rate-dependent) e.g. salt

Strat model deformation model A key target is to investigate sensitivities in both model elements to choices of time increments, rheological properties, deposition rules and the spatial resolution

Strat model PetroDynamics PHIL simulator. Build wedge geometry deposition flexural subsidence compaction Rheological properties Finite element deformation model Refine wedge geometry Impose a vector deformation field onto the strat model, (which entails modification of the seabed profile) A key target is to investigate sensitivities in both model elements to choices of time increments, rheological properties, deposition rules and the spatial resolution thermal subsidence Gravitational deformation Multiple scenarios

Sedimentation and deformation in deepwater fold-thrust belts Scales … The slope system (wedge dynamics) Individual/groups of folds/thrusts Evolution of fold-thrusts and fault zone architecture Scales … The slope system (wedge dynamics) Individual/groups of folds/thrusts Evolution of fold-thrusts and fault zone architecture deformation styles Deposition/strat architectures

Styles of contraction at toe of slope? thrusting folding strain Tectonic compaction ….

Little syn-thrusting sedimentation Sedimentation during thrusting Spaced anticlines, Little overlap Stacked with overlap

Sediment loading conditions influences mechanics of folding and faulting… Structural activity influences mini-basin evolution

Sedimentation and deformation in deepwater fold-thrust belts Scales … The slope system (wedge dynamics) Individual/groups of folds/thrusts Evolution of fold-thrusts and fault zone architecture Scales … The slope system (wedge dynamics) Individual/groups of folds/thrusts Evolution of fold-thrusts and fault zone architecture deformation styles Deposition/strat architectures Stratigraphic controls on fault zone/forelimb architecture

WNW ESE (Example case study: Butler & McCaffrey 2004, Mar Petrol Geol)

detached panel of sandstone

WNW ESE

Substrate carbonates

WNW ESE

Interaction between distributed deformation -BUCKLING – and thrust faulting … Mechanical behaviour of multilayer influences thrust-fold zone evolution – and hence final architecture

Sedimentation and deformation in deepwater fold-thrust belts Scales … The slope system (wedge dynamics) Individual/groups of folds/thrusts Evolution of fold-thrusts and fault zone architecture Scales … The slope system (wedge dynamics) Individual/groups of folds/thrusts Evolution of fold-thrusts and fault zone architecture deformation styles Deposition/strat architectures

STRUCT STRAT ISSUES Large-scale slope evolution Numerical modelling Database of depositional/structural styles on modern slopes Deep-water fold-thrust belts Model sediment loading on fold-thrust arrays Quantify structural architectural elements and relate to deposition Data provision Fold-fault zone evolution Exceptional outcrop analogues - quantifiedNumerical modelling of multilayers modellingobservations

Sediment patterns on slopes. External controls on deep water clastic systems The bathymetric influence on sediment deposition Structural evolution Why? Sed load drives/modifies slope structure Sed style impacts wedge rheology Sed architecture impacts on fault zone evolution Multi-disciplinary project e.g. TRG geometry mechanics Consortium Pathfinder Establish workflows Focus deliverables Develop partnerships

Program Pathfinder: mid-late 2005 Main consortium: Sept Costs: Pathfinder £26k ($50k) per sponsor Main Struct-Strat consortium (3 years) £30k per sponsor/year Discounted to £27k for Pathfinder or TRG Phase 5 sponsors Discounted to £24k for sponsors of both of the above. Early access to results Better alignment of research results to sponsor needs Discounted participation of consortium Priorities driven by pathfinder sponsors – activities depend on number of sponsors