Mechano-chemical interface processes with application to rock weathering
Appears in the following Collection
- Fysisk institutt 
AbstractThe object of this thesis is to study the coupling of chemical and physical processes during rock weathering. Stresses which are produced due to chemical reactions can lead to fracture propagation which in turn increases the transport of reactants and the reactive surface area, and this coupling can therefore control overall rate of weathering. It is shown that weathering induced expansion can drive a hierarchical fracture process where originally intact rock is broken into progressively smaller blocks. Studies are also made on the micrometer scale in order to gain a more fundamental understanding both of fracture propagation and reaction induced stresses. It was found experimentally that the local chemistry has a profound effect on the velocity of fracture propagation in single crystals of calcite when stresses are applied slowly. This is related to the interaction between the mineral surface and water. Experiments on the so-called force of crystallisation showed that the process in which a crystal growing from a supersaturated solution can push on a neighbouring wall is more complex than previously assumed. This has implications for the understanding of how stresses evolve when crystals grow in a porous material.
List of papers. Papers I and II are removed from the thesis due to copyright restrictions.
Paper I Controls on rock weathering rates by reaction-induced hierarchical fracturing. Anja Røyne, Bjørn Jamtveit and Anders Malthe-Sørenssen (2008) Earth and Planetary Science Letters, 275, 364-369 doi:10.1016/j.epsl.2008.08.035
Paper II Growth rims and interface structure of a crystal face growing from solution while exerting a force of crystallization. Anja Røyne and Dag Kristian Dysthe Manuscript, not yet published.
Paper III Experimental investigation of surface energy and subcritical crack growth in calcite. Anja Røyne, Jan Bisschop and Dag Kristian Dysthe (2011) Journal of Geophysical Research - Solid Earth, 116, B04204 Copyright 2011 by the American Geophysical Union. doi:10.1029/2010JB008033
Paper IV Subcritical crack propagation driven by crystal growth. Anja Røyne, Paul Meakin, Anders Malthe-Sørenssen, Bjørn Jamtveit and Dag Kristian Dysthe. Submitted manuscript. Published as: Crack propagation driven by crystal growth EPL (Europhysics Letters) Volume 96 Number 2, 96 24003. Copyright 2011 EPLA. doi:10.1209/0295-5075/96/24003