HR: 1340h
AN: T33C-1500    [Abstracts]
TI: Solid-solid phase transformation: Roughening of stylolites
AU: * Angheluta, L
EM: luiza.angheluta@fys.uio.no
AF: Physics of Geological Processes, Univ. of Oslo, Sem Selandsv. 24, Physics Building, 4th floor, Oslo, 0316, Norway
AU: Jettestuen, E
AF: Physics of Geological Processes, Univ. of Oslo, Sem Selandsv. 24, Physics Building, 4th floor, Oslo, 0316, Norway
AU: Mathiesen, J
EM: joachim.mathiesen@fys.uio.no
AF: Physics of Geological Processes, Univ. of Oslo, Sem Selandsv. 24, Physics Building, 4th floor, Oslo, 0316, Norway
AU: Renard, F
AF: Physics of Geological Processes, Univ. of Oslo, Sem Selandsv. 24, Physics Building, 4th floor, Oslo, 0316, Norway
AU: Jamtveit, B
AF: Physics of Geological Processes, Univ. of Oslo, Sem Selandsv. 24, Physics Building, 4th floor, Oslo, 0316, Norway
AB: Sedimentary rocks under uniaxial compression often react by changing the texture during compaction or cementation, which is accompanied by the formation of stylolites spanning the grain contacts or the rocks along surfaces normal to the applied stress. Many field observations corroborate a common feature of stylolites, namely that they are rough interfaces that contain insoluble minerals. Stylolites are outstanding examples of interfacial patterns developed in out-of-equilibrium systems. We study the roughening of stylolites within a model of a moving interface boundary between two stressed solids. The set up of our model consists of two dissimilar elastic bodies that are separated by a sharp interface and subjected to uniform compression in the direction perpendicular to the interface profile. Based on the balance laws of force and energy, we derive the jump conditions for a moving interface driven by a phase transformation process, i.e. the solid phase with higher energy (more porous) is removed and replaced by the same amount of less porous solid phase. An initially flat interface perturbed with small irregularities develops grooves or finger like structures, which align with the principal direction of compaction. The system is dissipative and approaches asymptotically the equilibrium configuration between the two phases. Our numerical investigations reveal several issues: 1) a morphological instability of the solid-solid interface does develop; 2) the instability is driven by the porosity jump across the interface; 3) the energy concentration at the tip of the fingers may influence the development of cracks perpendicular to the stylolites planes, as observed in nature.
DE: 0545 Modeling (4255)
DE: 3215 Instability analysis
DE: 3675 Sedimentary petrology
DE: 3947 Surfaces and interfaces
DE: 4430 Complex systems
SC: Tectonophysics [T]
MN: 2007 Fall Meeting