Geological Folds arise from the in plane compression of layers of rocks from tectonic plate movement. Sometimes layers buckle as a single layer, however more often than not geologists encounter multilayered structures. Such structures arise from a sequence of sedimentary deposits, subseqently held together by the weight of overlying layers. The resulting deformation patterns not only depend on the mechanical properties of each layer, but the complex geometric constraints of them fitting together.
It is well understood that a layers' resistance to buckling is proportional to the cubic of its thickness, i.e. for a layer just four times as thick as other layers, the resistance to buckling will be sixty four times greater. Consequently the presence of a thicker layer within a multilayered stack will overrides the buckling behaviour. Such layers are term control units, where this dominant layer behaves much like a single layer, and the surrounding thinner layers must fit into the geometry imposed.
As a results for particularly tight geometries various patterns form on the localized length scale, such structures are duely named accomodation structures, which include void formation [Dodwell et al. 2011], boundinage structures and parasitic folds [Price and Cosgrove, pp. 391].
During my PhD over the last three years I have investigate such structures, particularly studying the interplay between mechanical properties and constrained geology. By its nature the work covers a wide range of topics, nonlinear mechanics, variational calculus, numerical techniques for boundary value problems, bifurcation theory to name a few.Recent Publications:
- Tim Dodwell, Mark A. Peletier, Chris Budd, and Giles W. Hunt, Self-similar voiding solutions of a single layered model of folding rocks (arXiv:1101.5325), submitted (2011).