Precipitation of mineral aggregates near the Earth's surface or in
subsurface fractures and cavities often produces complex microstructures
and surface morphologies. Here we demonstrate how a simple surface
normal growth (SNG) process may produce microstructures and surface
morphologies very similar to those observed in some natural carbonate
systems. A simple SNG model was used to fit observed surfaces, thus
providing information about the growth history and also about the
frequency and spatial distribution of nucleation events during growth.
The SNG model can be extended to systems in which the symmetry of
precipitation is broken, for example by fluid flow. We show how a simple
modification of the SNG model in which the local growth rate depends on
the distance from a fluid source and the local slope or fluid flow rate,
produces growth structures with many similarities to natural travertine
deposits. (c) 2006 Elsevier B.V. All rights reserved.