HR: 14:25h
AN: B13E-04    [Abstracts]
TI: Determinism and Chaos: The Role and Importance of Nonlinear Interactions Involving Elementary Surface Mechanisms in the Dissolution Of Crystalline Materials
AU: * Luttge, A
EM: aluttge@rice.edu
AF: Rice University, Department of Earth Science MS-126 P.O. Box 1892, Houston, TX 77251-1892 United States
AU: Arvidson, R S
EM: rsa4046@ruf.rice.edu
AF: Rice University, Department of Earth Science MS-126 P.O. Box 1892, Houston, TX 77251-1892 United States
AB: Much of the work involving the reaction kinetics of crystalline materials implicitly assumes that reaction rates are constant for a given set of externally imposed physical and chemical conditions, an assumption often justified by observations of exponential approach of an experimental rate to a (quasi)steady state value. In crystal dissolution experiments, we formalize this result by assigning rate {\it{constants}} to reactions that are presumably free of composition and surface area terms. In a general way, we also assume that crystal dissolution far from equilibrium is free of feedback effects that often characterize dissipative systems during crystal growth, in which nonlinear relationships involving reaction and mass transport give rise to self-organized phenomena such as oscillatory zoning and other spatial distributions. However, there is no {\it{a priori}} reason to expect that feedback effects cannot also characterize dissolution reactions, or that such interactions may give rise to outcomes that are uniquely predictable. We now have the opportunity to observe such phenomena in nano-scale processes involving the evolution of surface topography undergoing dissolution, both with and without microbial intervention. We test this hypothesis through an examination of AFM and vertical scanning interferometry results, kinetic Monte Carlo modeling, and theoretical considerations, and discuss how crystal surfaces may yield dynamical examples of deterministic chaos.
DE: 3620 Crystal chemistry
DE: 1886 Weathering (1625)
DE: 1045 Low-temperature geochemistry
DE: 0400 Biogeosciences
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting