Lower crustal flow
Movement of material in the Earth's crust
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In geodynamics lower crustal flow is the mainly lateral movement of material within the lower part of the continental crust by a ductile flow mechanism. It is thought to be an important process during both continental collision and continental break-up.[1]
Rheology
The tendency of the lower crust to flow is controlled by its rheology. Ductile flow in the lower crust is assumed to be controlled by the deformation of quartz and/or plagioclase feldspar as its composition is thought to be granodioritic to dioritic. With normal thickness continental crust and a normal geothermal gradient, the lower crust, below the brittle–ductile transition zone, exhibits ductile flow behaviour under geological strain rates. Factors that can vary this behaviour include: water content, thickness, heat flow and strain-rate.
