Presentation on theme: "By Willy Fjeldskaar Rogalandsforskning. It is generally accepted that the present-day elevated topography of Scandinavia is partly due to significant."— Presentation transcript:
It is generally accepted that the present-day elevated topography of Scandinavia is partly due to significant Late Tertiary surface uplift The driving mechanism of this uplift is not resolved Late Tertiary uplift
Post-glacial uplift It is generally accepted that the present uplift of Fennoscandia is connected to the melting of the last ice sheets in the area The driving mechanism of this uplift is glacial isostasy
1) present rate of uplift 2) palaeo shoreline tilt
Ice extent and thickness during the last 20 000 years
The Earth's response to the deglaciation in Fennoscandia is modelled using a layered viscous model with elastic lithosphere. “The most likely ice model gives a flexural rigidity of 10 23 Nm (t e = 20 km) at the Norwegian coast, increasing to more than 10 24 Nm (t e = 50km) in central parts of Fennoscandia” (Fjeldskaar, 1997) (Fjeldskaar & Cathles, 1991)
01234567 40 60 80 100 120 140 Viscosity (10 19 Pa s) Viscosity vs. thickness
BMT TM is an advanced 2D basin modeling system with ability to create area balanced cross sections in environments with normal or reversed faults, and to analyze the interplay between tectonic processes, heat flow and timing of generation. BMT also has the power to analyze complex tectonic processes including salt diapirism and igneous intrusions, and to model the related heat flow response.
Erosion Porosity/Depth trends Fault model Age Model Representation of Present-Day Geology Reconstruction of Geologic section Tectonic modelling Input parametersUncertaintyModeling task Interpreted seismic line Structural Framework Fault Geometries Porosity / Depth trends Palaeo water depths Lithospheric properties Rifting Event Characteristics Depth Conversion Interpretation Magnitude/Timing of Rifting Lithospheric properties Palaeo water depths Tectonic modeling
Tectonic modeling in BMT Reconstruction of the basin geometry evolution Fault restoration Isostatic deflections (w/ flexure) Lithospheric thinning (w/ necking) Magmatic intrusions/underplating Salt movements Intra plate stress (Phase boundary migration) - and their temperature effects – integrated in one system
1) One by one layer is removed 2) The layers underneath are decompacted (by porosity-depth relation) 3) The fault blocks are translated up the fault system (by vertical shear) until the top timeline is continuous across the fault surface.
yeardeliverablesamount 2005New and high resolution ice models of last glaciation Global high resolution modelling400 kNOK 2006Modelling results of last glaciation with high resolution Ice thickness for previous glaciations/modelling1226 kNOK 2007Modelling of previous glaciations Modelling of first 2D section (prel.)1326 kNOK 2008Modelling of erosion/deposition Modelling of second 2D section1326 kNOK 2009Finalizing modelling – 2D and 3D Reporting1026 kNOK Activity schedule