The Coulomb critical taper theory applied to gravitational instabilities. Issue 1 (29th January 2014)

• Record Type: Journal Article
• Authors: Mourgues, R.; Lacoste, A.; Garibaldi, C.
• Is Part Of: Journal of geophysical research. Volume 119:Issue 1(2014:Jan.)
• Page Start: 754
• Page End: 765
• Publication Date: 2014-01-29
• Subjects: Geomagnetism -- Periodicals; Geochemistry -- Periodicals; Geophysics -- Periodicals; Earth sciences -- Periodicals; 551.1
• DOI: 10.1002/2013JB010359
• Languages: English
• ISSNs: 2169-9313

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <p>The critical Coulomb wedge theory has been widely applied to the structural evolution of accretionary wedges and fold and thrust belts, but it also predicts the spreading of a wedge under gravity. This solution may be applied to the formation of gravitational spreading and gliding along passive margins, where elevated pore fluid pressure is common. Following the initial hypotheses of the theory, we provide an alternative expression of the exact solution for a noncohesive wedge, better suited to slope instabilities. Our formulation allows a direct calculation of the fluid pressure required for the system to deform and predicts two kinds of gravitational deformation: shallow slumping and/or deep gravitational spreading rooting on the basal detachment. To verify the predictions of the model, we performed scaled experiments with pore pressure under conditions close to the critical taper hypotheses. The good agreement between our experimental results and the theory confirms the applicability of the critical taper model to the formation of gravitational structures in sedimentary wedges subjected to pore fluid pressure.</p> </abstract>