|When:||Friday, Sept. 02, 2011, 10:30 a.m. to 11:30 a.m.
Join us for coffee beginning at 10:00 a.m.
|Where:||Seminar Conference Room, 10100 Burnet Road, Bldg 196-ROC, Austin, Texas 78758|
|Host:||Charles Jackson, UTIG|
We model salt as a viscoelastic material and the underlying sediments as porous-elastic materials. We show that the contact properties, the topography of the salt and also the presence of overpressures in the sediments affect the dominant mechanism of salt advance. Both base shear and frontal rolling may be present during salt emplacement, with sliding being more typical of the salt toe, and rolling of the rear. If no overpressures are present, base-salt sliding will eventually deactivate and frontal rolling will dominate. However, excess pore pressures may be present, due to a rapid salt emplacement over sediments with low coefficient of dissipation. In such cases, the effective stress within the sediments does not increase despite the accumulation of material caused by the advance, and consequently the shear resistance remains low. As a result, sliding becomes the dominant mechanism. These results appear to have many analogies with ice-sheet advance, and I am looking forward to your feedback!