rob butler and bill mccaffrey please pass comments back to: [email protected]...

Rob Butler and Bill McCaffrey

Please pass comments back to:[email protected]@earth.leeds.ac.uk

http://earth.leeds.ac.uk/struc-strat/project-descriptions

Outline

STRUCT-STRATThe linked study of deformation and depositional processes on submarine slopes

VIRTUAL SEISMIC ATLASKnowledge Transfer community initiative

School of Earth and EnvironmentUniversity 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 LeedsOutline the scientific challengesResearch Program

Pathfinder projectConsortium project

Please pass comments back to:[email protected]@earth.leeds.ac.uk

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 studentsMSc Structural Geology with Geophysics

Turbidites Research Group (TRG) 12 years deep marine clastics researchBill 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. Collectivelywe have published over 150 research papers and supervised >40 research students.

Rob Butler25 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 McCaffreyCurrently 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, particularlythe 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

OutlineUPDATE – FROM POTENTIAL SPONSORSOutline the scientific challengesResearch Program

Pathfinder projectConsortium project

http://earth.leeds.ac.uk/struc-strat

UPDATE – April 2005.

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 rheologySed architecture impacts on fault zone

evolution

Multi-disciplinaryproject

e.g. TRG

geometrymechanics

Consortium

Pathfinder

Establish workflowsFocus deliverablesDevelop 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…




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.

viscous plastic

SEDIMENTWEDGE

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

flexuralsubsidencecompaction

Rheologicalproperties

Finite element deformation model Refine

wedgegeometry

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

Gravitationaldeformation

Multiple scenarios

Multiple scenarios

Sedimentation and deformation in deepwater fold-thrust belts

Scales…




Scales…





Styles of contraction at toe of slope?

thrusting

folding

strain

Tectonic compaction….

Little syn-thrustingsedimentation

Sedimentationduringthrusting

Spaced anticlines,Little overlap

Stacked with overlap

Sediment loading conditions influences mechanics of folding and faulting…

Structural activity influences mini-basin evolution


Scales…




Scales…





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 betweendistributed deformation-BUCKLING – andthrust faulting…

Mechanical behaviour of multilayer influences thrust-fold zone evolution –and hence final architecture


Scales…




Scales…





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

modelling observations

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 rheologySed architecture impacts on fault zone

evolution

Multi-disciplinaryproject

e.g. TRG

geometrymechanics

Consortium

Pathfinder

Establish workflowsFocus deliverablesDevelop partnerships

Program

Pathfinder: mid-late 2005

Main consortium: Sept 2006 - 2009

Costs:

Pathfinder £26k ($50k) per sponsor

Main Struct-Strat consortium (3 years)£30k per sponsor/yearDiscounted to £27k for Pathfinder or TRG Phase 5 sponsorsDiscounted to £24k for sponsors of both of the above.

Early access to resultsBetter alignment of research results to sponsor needsDiscounted participation of consortium

Priorities driven by pathfinder sponsors – activities depend on number of sponsors
