The Different Processes Involved in the Mechanism of Pressure Solution in Quartz-Rich Rocks and their Interactions
- Richard H. Worden4,
- Sadoon Morad5
Published Online: 17 MAR 2009
Copyright © 2000 The International Association of Sedimentologists
Quartz Cementation in Sandstones
How to Cite
Renard, F., Brosse, É. and Gratier, J. P. (2009) The Different Processes Involved in the Mechanism of Pressure Solution in Quartz-Rich Rocks and their Interactions, in Quartz Cementation in Sandstones (eds R. H. Worden and S. Morad), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444304237.ch5
School of Geosciences, The Queen's University, Belfast, BT7 1NN, UK
Sedimentary Geology Research Group, Institute of Earth Sciences, Uppsala University, Norbyvägen 18 B, S–75236, Uppsala, Sweden
- Published Online: 17 MAR 2009
- Published Print: 3 MAR 2000
Print ISBN: 9780632054824
Online ISBN: 9781444304237
- pressure solution in quartz-rich rocks and their interactions;
- pressure solution - efficient mechanism for rock deformation and compaction in upper crust;
- stability and properties of trapped water film;
- driving force for pressure solution;
- importance of rock geometry;
- effects of stress and temperature on deformation;
- clay minerals promoting mineral dissolution through ‘water film diffusion’
Pressure solution is a very efficient mechanism for rock deformation and compaction in the upper crust. It is controlled by stress, temperature, and grain size. The mechanism commonly used to describe deformation by pressure solution at a grain scale, the ‘water film diffusion’ mechanism, can be divided into three successive steps: (i) dissolution at the grain interface; (ii) diffusion of solutes along an adsorbed water film inside the contact between two grains; (iii) precipitation on the surface of the grains adjacent to the open pore. The slowest step controls the rate of the overall process.
Important geometrical variables controlling the pressure solution rate are the grain size and the geometry of the grain–grain interface. Knowledge of the geometry permits estimation of the path length for diffusion of the solutes from the contact between the grains to the pore. Physicochemical variables are important also, including: temperature, stress, chemistry of the pore water, mineralogy of the rock, and thickness of the water film trapped between the grains.
In pressure solution, different coupled variables are involved on several spatial scales: the water film thickness at a nanometre scale, the geometry of the surface of contact at a micrometre scale, and the grain size and texture of the rock at a millimetre to centimetre scale. To understand the mechanism of pressure solution, the values of all these variables must be evaluated to estimate the kinetics of the various coupled processes in which they are involved. These variables can be modelled to determine: (i) the conditions under which pressure solution is efficient in sedimentary basins; (ii) the parameters that control the rate of pressure solution and quartz cementation. The result is a model that can estimate the porosity variations and quartz cementation due to pressure solution, as a function of pressure, temperature, and rock texture.