Abstract |
Analog sandbox models allow plate tectonic deformation of the crust over geological timescales to be studied on the tabletop. Using a new sandbox model we have built in the Department of Geology, I am investigating how different bedding thicknesses, represented in the model by layers of coloured sand, can alter the style of deformation during experiments that simulate tectonic convergence. My central hypothesis is that if the beds are thicker then more convergence is accommodated by internal deformation within the beds, rather than slip between the beds. This leads to gentle folding of the layers rather than sharper kinking and faulting. My experiments involve filling a box with clear perspex sides, on top of a moving base plate, with layers of sand of varying colors (to represent different strata and beds). The whole sand pile is deformed by gradually pushing the base plate underneath a fixed backstop, with digital photographs being taken through the perspex sides at regular intervals to record how faults and folds develop. In addition to multiple experiments that vary average layer thickness from millimeter to centimeter scale, I also plan to test how other parameters such as width of the deforming region and obliquity of convergence, may affect my results.
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Modified Abstract |
Using a sandbox model we built in the Geology Department, I am investigating how bedding thicknesses can alter the deformation during simulated tectonic convergence. My hypothesis is, if the beds are thicker then more convergence is accommodated by internal deformation within the beds, rather than slips between the beds. This leads to gentle folding of the layers rather than sharper faulting. My experiments involve filling a box, on top of a moving base plate, with layers of varying colored sand. The whole sand pile is deformed by pushing the base plate, with photographs taken at regular intervals to record how faults and folds develop. In addition to experiments that vary layer thickness, I also plan to test how other parameters may affect my results.
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