1. Ellipsis Modelling Scott Dyksterhuis Dietmar Müller, Louis Moresi and Patrice Rey University of Sydney

2. Geodynamics Combined mantle convection and plate kinematic modelling Palaeostress modelling Dynamic basin modelling (mantle convection, lithos- pheric thinning, sedimentation/ erosion) Basin history Put constraints on tectonic/thermal history of deep sedimentary sections Constrain timing of fault reactivation by combining palaeo-stress modelling with observations from seismic data Seismic and well data integration and interpretation Lithologies Physical properties Biostratigraphy Basin geometry Faulting through time

3. Geological modeling is associated with a different set of requirements: Very large deformation of solid materials including accurate tracking of material (compositional) interfaces – melt? accurate tracking of history variables evolution of oriented structure etc… Only want a tool to fit data/concepts (geometry, thermal history, potential field) Easy use and implement

4. Ellipsis A particle-in-cell finite element code that solves 2D and 3D fluid mechanics problems with & w/o heat transfer, e.g., –Mantle convection –Lithospheric deformation –subduction Ellipsis works with a multigrid solver, which allows quite rapid solutions (but does constrain allowable mesh geometry) Solid-like materials can be given higher viscosities than fluid-like materials, or material properties can depend on temperature, depth, pressure, strain, strain rates, etc.

5. Ellipsis GUI Java based GUI for easy interaction with existing models or for creating new ones Allows for more complicated geometries – can even use drawings (based on seismic, reconstructions etc) to create models Handles all scaling automatically so user can do as much/little as they want

6. Ellipsis3D…

7. Interactive Inversion - Nimrod NIMROD, NIMROD/G manage the distribution of parameter-space studies on clusters / grids – robust job distribution – secure –visual feedback / portal NIMROD/O contains a number of objective inversion algorithms to reduce the number of models evaluated –Models are cached –Multiple inversions to help avoid local minima

8. Initial Conditions Evolution of the geotherm through time… Rheology Strain rate

9. Initial Conditions Fernandez & Ranalli, 1997

10. Lower Crustal Strength Models Relatively high lower crustal strength Wijns, in press

11. Lower Crustal Strength Models Relatively low lower crustal strength Wijns, in press

12. 4 Layer models Strong upper mantle lithosphere Distributed Core complex

13. Mantle Rheology

14. Juxtaposed Craton Relatively strong “craton” Artemieva & Mooney 2001

15. Conclusions Initial constrains extremely important –temperature –rheology Modelling not ready for applied examples? Accessibility of code important – get the geologist using the modelling software

16. A student’s perspective… Need to have some kind of online materials (rheology) database – Initial conditions A permanent web presence/meeting point (wiki site): –Codes, manuals, (benchmark) results (corner store) –community collaboration and “sounding ground” –centralised location for groups to benchmark codes/results –location for observationalists to pose “challenges” –data