Journal article
Phenomenological superplasticity in rocks
Deformation Mechanisms, Rheology and Tectonics, Vol.54(1), pp.229-240
1990
DOI: 10.1144/GSL.SP.1990.054.01.22
Abstract
Superplastic deformation of rocks can be defined as: homogeneous deformation without loss of continuity to very large strains. This phenomenological definition differs from current geological usage that equates superplasticity with either grain boundary sliding, a deformation mechanism, or with a specific set of material parameters. Two examples of natural, phenomenological superplasticity in rocks are presented. A diabase dyke deformed continuously in progressive simple shear to shear strains of at least γ = 100, despite the low grade of metamorphism and relatively coarse grain size of the resultant tectonite. Very coarse-grained pegmatite dykes show continuous deformation to high strains under predominantly pure flattening; intracrystalline plasticity was an important micromechanism of flow. A much wider range of material and mechanical parameters and physical conditions give rise to phenomenological superplasticity in rocks than predicted by experiments on metals. By inference and example, more deformation mechanisms will be associated with superplasticity in nature. The profound differences between the metallurgical experiments and the geological environment prohibit simple rheological interpretations of natural superplastic behaviour.
Details
- Title: Subtitle
- Phenomenological superplasticity in rocks
- Creators
- Jane A Gilotti - Geology Institute, University of UppsalaBox 555, S-751 22 Uppsala, SwedenJoseph M Hull - Geology Institute, University of UppsalaBox 555, S-751 22 Uppsala, Sweden
- Resource Type
- Journal article
- Publication Details
- Deformation Mechanisms, Rheology and Tectonics, Vol.54(1), pp.229-240
- Publisher
- The Geological Society, London
- DOI
- 10.1144/GSL.SP.1990.054.01.22
- ISSN
- 0305-8719
- eISSN
- 2041-4927
- Language
- English
- Date published
- 1990
- Academic Unit
- Earth and Environmental Sciences
- Record Identifier
- 9984229300602771
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