ABSTRACT Some authors consider that linear dunes migrate laterally on a grand scale, much as rivers move across floodplains. Others have concluded that lateral movement is limited in time and space. During the phase of dune initiation, small ribbons of sand formed in the lee of obstacles merge and coalesce to form recognisable linear dunes. Repeat observations demonstrate that mature sand ridges change position laterally a few metres either way within close limits defined by sand spillages on the slip or avalanche slopes that change orientation in response to changing sand-moving wind directions. This essay considers evidence by which to differentiate these two points of view. Supporting evidence for limited migration take the form of dunes resting on plinths of older alluvial substrates, some capped by gibber and that stand higher than adjacent interdune corridors. Such exposures show that the sand ridges have not migrated laterally during the last several tens of thousands of years. Migration is inhibited by clay cores, calcareous (calcrete) horizons, and the development of vegetated flanks. For these reasons, it is proposed that lateral migration be defined as a change of dune plan position that is greater than the maximum extent of sand deposition that develops in response to changes in the direction of sand-moving winds.

中文翻译：

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澳大利亚中部纵向沙丘的横向稳定性

摘要 一些作者认为线性沙丘大规模横向迁移，就像河流穿过洪泛区一样。其他人则得出结论，横向运动在时间和空间上是有限的。在沙丘形成阶段，障碍物背风处形成的小沙带合并并合并形成可识别的线性沙丘。重复观察表明，成熟的沙脊在由滑坡或雪崩斜坡上的沙子溢出所定义的封闭范围内横向改变位置几米，这些斜坡或雪崩斜坡改变方向以响应改变的沙子移动风向。本文考虑了区分这两种观点的证据。支持有限迁移的证据采取沙丘形式，位于较旧的冲积基质的基座上，一些被胡须盖住，比相邻的沙丘间走廊还要高。这种暴露表明沙脊在过去几万年中没有横向迁移。迁移受到粘土岩心、钙质（钙质）地层和植被侧翼发展的抑制。由于这些原因，建议将横向迁移定义为沙丘平面位置的变化，该变化大于响应于移动沙风方向变化而发展的沙子沉积的最大范围。