Hostname: page-component-cd9895bd7-p9bg8 Total loading time: 0 Render date: 2024-12-25T01:01:57.952Z Has data issue: false hasContentIssue false
  • English
  • Français

Crack–reaction veins from the Hodgkinson Formation, North Queensland, Australia

Published online by Cambridge University Press:  01 May 2009

A. Forde  and
B. K. Davis
A. Forde
Affiliation:
Geology Department, James Cook University, Townsville, Queensland 4811, Australia
B. K. Davis*
Affiliation:
Geology Department, James Cook University, Townsville, Queensland 4811, Australia
*
*Author for correspondence
Get access Rights & Permissions [Opens in a new window]

Abstract

Thin, subplanar or parallel-sided syntectonic quartz veins from the Hodgkinson Province, North Queensland, Australia contain mica inclusions that are identical to wallrock mica textures. These ghost textures can only be produced by incomplete replacement of the wallrock by quartz. The planar form of the veins indicates that there was a planar control on their formation. We propose that the veins formed around syntectonic fractures that localized silica micrometasomatism of the fracture wall. The formation of the veins can be explained by a model which involves fracture of the wallrock, reaction between the fracture wall and the ambient metamorphic fluid and eventual sealing of the fracture by precipitation from the fluid. The new vein is then a locus of further fracture. Replacement of wallrock micas occurs via a two-stage process where biotite is replaced by muscovite, which is in turn replaced by quartz. We propose the term crack–reaction to describe the resulting cyclic process because it can be compared with the crack–seal model of vein formation. Crack–seal and crack–reaction are different only in the relative amounts of metasomatism and precipitation that occur subsequent to fracture and can be envisaged as end members of a more general vein-forming process.

Type
Articles
Information
Geological Magazine , Volume 131 , Issue 1 , January 1994 , pp. 49 - 56
Copyright
Copyright © Cambridge University Press 1994

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Amos, B. J. 1968. The Structure of the Palaeozoic Sediments of the Mossman and Cooktown Areas, North Queensland. Journal of the Geological Society of Australia 15, 195–208.CrossRefGoogle Scholar
Bell, T. H. 1981. Foliation development: the contribution, geometry and significance of progressive bulk inhomogeneous shortening. Tectonophysics 75, 273–96.CrossRefGoogle Scholar
Bell, T. H., Perkins, W. G. & Swager, C. P. 1988. Structural controls on the development and localization of syntectonic copper mineralization of Mount Isa, Queensland. Economic Geology 83, 69–85.CrossRefGoogle Scholar
Bucher-Nurminen, K. 1981. Formation of metasomatic reaction veins in dolomite roof pendants in the Bergall intrusion (Province Sondrio, Northern Italy). American Journal of Science 281, 1197–1222.CrossRefGoogle Scholar
Bucher-Nurminen, K. 1989. Reaction veins in marbles formed by a fracture–reaction–seal mechanism. European Journal of Mineralogy 1, 701–14.CrossRefGoogle Scholar
Bultitude, R. J. & Champion, D. C. 1992. Granites of the eastern Hodgkinson Province – their field and petrographic characteristics Government of Queensland, Department of Resource Industries Record no. 1992/6.Google Scholar
Cox, S. F. 1987. Antitaxial crack–seal vein microstructures and their relationship to displacement paths. Journal of Structural Geology 9, 779–87.CrossRefGoogle Scholar
Cox, S. F. & Etheridge, M. A. 1983. Crack–seal fibre growth mechanisms and their significance in the development of oriented layer silicate microstructures. Tectonophysics 82, 142–70.Google Scholar
Davis, B. K. 1993. Mechanism of emplacement of the Cannibal Creek Granite with special reference to timing and deformation history of the aureole. Tectonophysics (in press).CrossRefGoogle Scholar
Dewers, T. & Ortoleva, P. 1990. Geochemical self-organization. III: A mechano-chemical model of metamorphic differentiation. American Journal of Science 290, 473–521.CrossRefGoogle Scholar
Fisher, D. M. & Brantley, S. L. 1992. Models of quartz overgrowth and vein formation: Deformation and episodic fluid flow in an ancient subduction zone. Journal of Geophysical Research 97, 20043–061.CrossRefGoogle Scholar
Forde, A. 1991. The late orogenic timing of mineralization in some slate belt gold deposits, Victoria, Australia. Mineralum Deposita 26, 257–66.Google Scholar
Halfpenny, R. W. & Hegarty, R. A. 1991. Geology of the South Palmer River 1:100000 sheet area (7865) North Queensland. Government of Queensland, Department of Resource Industries Record no. 1992/6.Google Scholar
McCaig, A. 1987. Deformation and fluid-rock interaction in metasomatic dilatant shear bands. Tectonophysics 135, 121–32.CrossRefGoogle Scholar
Ramsay, J. G. 1980. The crack–seal mechanism of rock deformation. Nature 284, 135–39.CrossRefGoogle Scholar
Ramsay, J. G. & Huber, M. I. 1983. The techniques of modern structural geology. Volume 2, folds and fractures. Academic Press.Google Scholar
Richards, D. N. G. 1980. Palaeozoic granitoids of north-eastern Australia. In The geology and geophysics of Northeastern Australia (eds Henderson, R. A. and Stephenson, P. J.), pp. 229–46. Geological Society of Australia, Queensland Division.Google Scholar
Rubenach, M. J. & Bell, T. H. 1988. Microstructural controls on the role of graphite in matrix/porphyroblast exchange during synkinematic andalusite growth in a granitoid aureole. Journal of Metamorphic Geology 6, 651–66.CrossRefGoogle Scholar
Walther, J. V. & Helgeson, H. C. 1977. Calculation of the thermodynamic properties of aqueous silica and the solubility of quartz and its polymorphs at high pressures and temperatures. American Journal of Science 277, 1315–51.CrossRefGoogle Scholar
Wintsch, R. P. & Dunning, J. 1985. The effect of dislocation density on the aqueous solubility of quartz and some geologic implications: a theoretical approach. Journal of Geophysical Research 90, 3649–57.CrossRefGoogle Scholar