Open AccessIncorporating metamorphism in geodynamic models: the mass conservation problem
Author(s) -
Hetényi György,
Godard Vincent,
Cattin Rodolphe,
Connolly James A.D.
Publication year - 2011
Publication title -
geophysical journal international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0956-540X
DOI - 10.1111/j.1365-246x.2011.05052.x
Subject(s) - metamorphism , orogeny , eclogitization , geology , metamorphic rock , conservation of mass , tectonics , boussinesq approximation (buoyancy) , geophysics , subduction , seismology , paleontology , physics , meteorology , mechanics , oceanic crust , convection , natural convection , rayleigh number
SUMMARY Geodynamic models incorporating metamorphic phase transformations almost invariably assume the validity of the Boussinesq approximation that violates conservation of mass. In such models metamorphic density changes take place without volumetric effects. We assess the impact of the Boussinesq approximation by comparing models of orogeny accompanied by lower crustal eclogitization both with and without the approximation. Our results demonstrate that the approximation may cause errors approaching 100 per cent in characteristic measures of orogenic shape. Mass conservation errors in Boussinesq models amplify with model time. Mass conservative models of metamorphism are therefore essential to understand long‐term tectonic evolution and to assess the importance of the different geodynamic processes.