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HERO ID
534605
Reference Type
Journal Article
Title
The role of moisture cycling in the weathering of a quartz chlorite schist in a tropical environment: findings of a laboratory simulation
Author(s)
Wells, T; Binning, P; Willgoose, G
Year
2005
Is Peer Reviewed?
Yes
Journal
Earth Surface Processes and Landforms
ISSN:
0197-9337
EISSN:
1096-9837
Volume
30
Issue
4
Page Numbers
413-428
Language
English
DOI
10.1002/esp.1149
Web of Science Id
WOS:000228736300003
Abstract
Long-term weathering or a quartz chlorite schist via wetting and drying was studied under a simulated tropical climate. Cubic rock samples (15 mm x 15 mm x 15 mm) were cut from larger rocks and subjected to time-compressed climatic conditions simulating the tropical wet season climate at the Ranger Uranium Mine in the Northern Territory, Australia. Fragmentation, moisture content and moisture uptake rate were monitored over 5000 cycles of wetting and drying. To determine the impact of climatic variables, five climatic regimes were simulated, varying water application, temperature and drying. One of the climatic regimes reproduced observed temperature and moisture variability at the Ranger Uranium Mine, but over a compressed time scale. It is shown that wetting and drying is capable of weathering quartz chlorite schist with changes expected over a real time period of decades. While wetting and (Irving alone does produce changes to rock morphology, the incorporation of temperature variation further enhances weathering rates. Although little fragmentation occurred in experiments, significant changes to internal pore structure were observed, which could potentially enhance other weathering mechanisms. Moisture variability is shown to lead to higher weathering rates than are observed when samples are subjected only to leaching. Finally, experiments were conducted on two rock samples from the same source having only subtle differences in mineralogy. The samples exhibited quite different weathering rates leading to the conclusion that our knowledge of the role of rock type and composition in weathering is insufficient for the accurate determination of weathering rates. Copyright (c) 2005 John Wiley & Sons, Ltd.
Keywords
weathering; wet/dry cycling; tropical climate; porosity; quartz; chlorite schist; cold climates; salt; temperature; mechanisms
Tags
IRIS
•
Uranium
WOS
Merged reference set
Secondary Refinement
Excluded
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