Relating experimental and geological theology

This paper is concerned with the question of how to relate laboratory measu rements of the theology of rocks to the theological assumptions that need t o be made in geodynamic modelling. First, there is a brief resume of the pr incipal types of theological behaviour that have been studied in the labora tory, both pressure-dependent, strain rate-independent and pressure-indepen dent, strain-rate-dependent. Then, the generalization of the results from t he relatively simple stress states of the experiments to general stress sta tes is discussed, followed by consideration of the extrapolation of the exp erimental results to geological strains and strain rates. Finally, the prob lems associated with spatial scale are considered, leading to the question of how to model the theological behaviour of large-scale rock masses, using the theological measurements of laboratory specimens and taking into accou nt the heterogeneity of geological-scale rock masses.