Open AccessExperimental investigation of surface energy and subcritical crack growth in calcite
Author(s) -
Røyne Anja,
Bisschop Jan,
Dysthe Dag Kristian
Publication year - 2011
Publication title -
journal of geophysical research: solid earth
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2010jb008033
Subject(s) - calcite , cracking , brittleness , surface energy , materials science , fracture mechanics , growth rate , mineralogy , geology , composite material , geometry , mathematics
Subcritical cracking behavior and surface energies are important factors in geological processes, as they control time‐dependent brittle processes and the long‐term stability of rocks. In this paper, we present experimental data on subcritical cracking in single calcite crystals exposed to glycol‐water mixtures with varying water content. We find upper bounds for the surface energy of calcite that decrease with increasing water concentration and that are systematically lower than values obtained from molecular dynamics simulations. The relation of surface energy to water concentration can explain water weakening in chalks. The rate of subcritical crack growth in calcite is well described by a reaction rate model. The effect of increasing water on crack velocity is to lower the threshold energy release rate required for crack propagation. The slope of the crack velocity curve remains unaffected, something which strongly suggests that the mechanism for subcritical cracking in calcite does not depend on the water concentration.