The Reynolds Range, central Australia underwent contact metamorphism at 1.8
2 and 1.78 Ga; greenschist to granulite-facies regional metamorphism at 1.6
Ga; and metamorphism in shear zones at up to amphibolite facies at similar
to 334 Ma. Significant fluid how occurred during both contact metamorphic
events, cooling following regional metamorphism, and Alice Springs-age shea
ring. During cooling from regional metamorphism, fluids were derived "inter
nally" from partial melt crystallisation. However, contact metamorphism and
shearing involved external fluids, including some from the surface. Fluids
were channelled on scales ranging from hecto- to millimetres due to local
variations in intrinsic permeability resulting from deformation or reaction
enhancement. (C) 2000 Elsevier Science B.V. All rights reserved.