Physics
Scientific paper
Dec 2010
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010agufm.t51a2019r&link_type=abstract
American Geophysical Union, Fall Meeting 2010, abstract #T51A-2019
Physics
[5475] Planetary Sciences: Solid Surface Planets / Tectonics, [8005] Structural Geology / Folds And Folding, [8020] Structural Geology / Mechanics, Theory, And Modeling, [8122] Tectonophysics / Dynamics: Gravity And Tectonics
Scientific paper
Large scale gravity gliding are usually observed in deltas and passive margins. They imply the rigid translation of a body down a slope, with coeval upslope extension and downslope contraction. Displacement vectors are parallel to a buried detachment plane gently dipping basinward (1-5°). Field examples suggest that gravity gliding could be found in continental domains but contrary to oceanic environments, upslope sedimentation and pore fluid overpressure do not play a major role. These lacks must be compensated. This study investigates mechanisms generating gravity gliding in a continental domains through the use of a two-dimensional (2D) finite-element model and a 2D analytical failure analysis. We focus on the role of tectonic uplifts and the subsequent fluvial incision and sedimentation at the toes of the slopes. The geometries of the numerical models are based on a field example in the Andean foothills of Argentina. Gravity gliding occurs along the long limb of an asymmetric crustal-scale anticline, above a 1000 m depth salt layers. The numerical models simulate the deformations and estimate quantitatively the circumstances under which failure at the head and toe of the frictional-plastic sedimentary cover initiates. Analytical solutions give simplified approximation of the numerical results taking into account many configurations with various values of the incision, sedimentation, internal friction angle and thickness of the décollement layer. The principal effect of the incision and sedimentation is to reduce and strengthen the downslope resistance to the contractional failure. Consequently, the magnitude of the critical slope for which the gravity gliding initiates, is reduced by the incision and is increased by the sedimentation. Results show that large-scale gravity gliding can be found in continental domains as a consequence of tectonic uplifts and where overburden thickness is lower than 2000 m. Incision facilitates and localizes the gliding. Overburden thickness of 4000 m could unstable when incision reaches 1000-2000 m-depth. Sedimentation higher than 1000 m-thick would inhibit in nature gravity-driven slides. We infer that large-scale gravity gliding could be common in tectonically active regions which contain salt layers and where incision is the rule.
Messager G.
Nivihre B.
Riad H.
No associations
LandOfFree
The Role of Incision and Sedimentation in Continental Gravity Gliding - Insight from Numerical Modelling does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The Role of Incision and Sedimentation in Continental Gravity Gliding - Insight from Numerical Modelling, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Role of Incision and Sedimentation in Continental Gravity Gliding - Insight from Numerical Modelling will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1500269