DOI: 10.1038/ngeo2209
论文题名: Sandstone landforms shaped by negative feedback between stress and erosion
作者: Bruthans J. ; Soukup J. ; Vaculikova J. ; Filippi M. ; Schweigstillova J. ; Mayo A.L. ; Masin D. ; Kletetschka G. ; Rihosek J.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2014
卷: 7, 期: 8 起始页码: 597
结束页码: 601
语种: 英语
英文摘要: Weathering and erosion of sandstone produces unique landforms such as arches, alcoves, pedestal rocks and pillars. Gravity-induced stresses have been assumed to not play a role in landform preservation and to instead increase weathering rates. Here we show that increased stress within a landform as a result of vertical loading reduces weathering and erosion rates, using laboratory experiments and numerical modelling. We find that when a cube of locked sand exposed to weathering and erosion processes is experimentally subjected to a sufficiently low vertical stress, the vertical sides of the cube progressively disintegrate into individual grains. As the cross-sectional area under the loading decreases, the vertical stress increases until a critical value is reached. At this threshold, fabric interlocking of sand grains causes the granular sediment to behave like a strong, rock-like material, and the remaining load-bearing pillar or pedestal landform is resistant to further erosion. Our experiments are able to reproduce other natural shapes including arches, alcoves and multiple pillars when planar discontinuities, such as bedding planes or fractures, are present. Numerical modelling demonstrates that the stress field is modified by discontinuities to make a variety of shapes stable under fabric interlocking, owing to the negative feedback between stress and erosion. We conclude that the stress field is the primary control of the shape evolution of sandstone landforms. © 2014 Macmillan Publishers Limited.
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/106508
Appears in Collections: 气候减缓与适应 科学计划与规划
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作者单位: Faculty of Science, Charles University in Prague, Albertov 6, 128 43 Prague 2, Czech Republic; Institute of Geology, AS CR, v. v. i., Rozvojova 269, 165 00 Prague 6, Czech Republic; Institute of Rock Structure and Mechanics, AS CR, v. v. i., V Holesovickach 41, 182 09 Prague 8, Czech Republic; Brigham Young University, Department of Geosciences, Provo, UT 84602, United States
Recommended Citation:
Bruthans J.,Soukup J.,Vaculikova J.,et al. Sandstone landforms shaped by negative feedback between stress and erosion[J]. Nature Geoscience,2014-01-01,7(8)