Reaction induced fracturing during replacement processes
Replacement processes are common transformation mechanisms in minerals and rocks at a variety of conditions and scales. The underlying mechanisms are, in general, poorly understood, but both mechanical and chemical processes are thought to be important. Replacement of leucite (KAlSi2O6) by analcime...
| Main Authors: | , , |
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| Format: | Journal Article |
| Published: |
Springer
2009
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| Online Access: | http://hdl.handle.net/20.500.11937/15071 |
| _version_ | 1848748795715649536 |
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| author | Jamtveit, B. Putnis, Christine Malthe-Sørenssen, A. |
| author_facet | Jamtveit, B. Putnis, Christine Malthe-Sørenssen, A. |
| author_sort | Jamtveit, B. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Replacement processes are common transformation mechanisms in minerals and rocks at a variety of conditions and scales. The underlying mechanisms are, in general, poorly understood, but both mechanical and chemical processes are thought to be important. Replacement of leucite (KAlSi2O6) by analcime (NaAlSi2 O6·H2O) is common in silica-poor igneous rocks. A 10% increase in volume is associated with the replacement process, and this generates stresses that eventually cause fracturing of the reacting leucite. Experimentally reacted leucite samples display characteristic fracturing patterns that include both spalling of concentric 'onion-skin'-like layers near the reacting interface and the formation of cross-cutting, often hierarchically arranged, sets of fractures that divide the remaining leucite into progressively smaller domains. These structures may explain the 'patchy' alteration patterns observed in natural leucite samples and similar, so-called, mesh-textures associated with the serpentinization of olivine grains during hydration of mafic or ultramafic rocks. They are also strikingly similar to larger scale patterns formed during spheroidal weathering processes. A simple discrete element model illustrates the mechanics that control the formation of such systems, and shows how these replacement processes may be accelerated due to the generation of new reactive surface area by hierarchical fracturing processes. © Springer-Verlag 2008. |
| first_indexed | 2025-11-14T07:10:43Z |
| format | Journal Article |
| id | curtin-20.500.11937-15071 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T07:10:43Z |
| publishDate | 2009 |
| publisher | Springer |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-150712017-09-13T15:04:45Z Reaction induced fracturing during replacement processes Jamtveit, B. Putnis, Christine Malthe-Sørenssen, A. Replacement processes are common transformation mechanisms in minerals and rocks at a variety of conditions and scales. The underlying mechanisms are, in general, poorly understood, but both mechanical and chemical processes are thought to be important. Replacement of leucite (KAlSi2O6) by analcime (NaAlSi2 O6·H2O) is common in silica-poor igneous rocks. A 10% increase in volume is associated with the replacement process, and this generates stresses that eventually cause fracturing of the reacting leucite. Experimentally reacted leucite samples display characteristic fracturing patterns that include both spalling of concentric 'onion-skin'-like layers near the reacting interface and the formation of cross-cutting, often hierarchically arranged, sets of fractures that divide the remaining leucite into progressively smaller domains. These structures may explain the 'patchy' alteration patterns observed in natural leucite samples and similar, so-called, mesh-textures associated with the serpentinization of olivine grains during hydration of mafic or ultramafic rocks. They are also strikingly similar to larger scale patterns formed during spheroidal weathering processes. A simple discrete element model illustrates the mechanics that control the formation of such systems, and shows how these replacement processes may be accelerated due to the generation of new reactive surface area by hierarchical fracturing processes. © Springer-Verlag 2008. 2009 Journal Article http://hdl.handle.net/20.500.11937/15071 10.1007/s00410-008-0324-y Springer restricted |
| spellingShingle | Jamtveit, B. Putnis, Christine Malthe-Sørenssen, A. Reaction induced fracturing during replacement processes |
| title | Reaction induced fracturing during replacement processes |
| title_full | Reaction induced fracturing during replacement processes |
| title_fullStr | Reaction induced fracturing during replacement processes |
| title_full_unstemmed | Reaction induced fracturing during replacement processes |
| title_short | Reaction induced fracturing during replacement processes |
| title_sort | reaction induced fracturing during replacement processes |
| url | http://hdl.handle.net/20.500.11937/15071 |