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Matthew R. Bennett 《Geological Journal》1993,28(1):81-88
A set of active stone stripes below a small debris cone in North Wales is described. In form they do not appear to resemble stone stripes described elsewhere. They are of particular note because their form is not controlled by conventional periglacial processes, but by stones moving downslope when sheep disturb the debris cone above. This downslope movement of stones has resulted in a complex pattern of stripes and horizontal terraces, the exact form of which appears to be controlled by probability. These observations add to the debate over the mode of formation of active stone stripes in Britain and the role of non-periglacial processes. 相似文献
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Stephen D. Holness 《地球表面变化过程与地形》2001,26(1):77-89
The orientation of sorted stripes developed in glacial deposits on Marion Island is examined. This study confirms earlier reports of preferential occurrence of sorted stripes on windward slopes. However, sorted stripes were also found to occur on low angle leeward slopes. Mechanisms for the orientation of sorted stripes by wind action are discussed. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
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Kevin Hall 《地球表面变化过程与地形》1979,4(3):281-289
Sorted stripes found on the volcanic scoria and glacial deposits of sub-Antarctic Marion Island indicate a distinct preferred orientation. Despite uniformity of slope and material, the stripes are predominantly aligned parallel to the wind. It is suggested that melting of needle ice by the early morning sun is of only limited importance in the sub-Antarctic owing to the almost continual overcast conditions. The effect of the wind is so great that in exposed situations stripes are formed on horizontal surfaces. 相似文献
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Kevin Hall 《地球表面变化过程与地形》1983,8(2):115-124
Observations of sorted stripes at nine different localities on sub-Antarctic Kerguelen Island are presented. The study sites range from 25-600 m above sea level and are of varying aspect. It is found that there is a strong relationship between stripe orientation and the wind direction, to the extent that at one locality stripes were orientated across a slope. Stripe width was seen to increase with altitude and, in addition, the coarse stripe was dominant at lower elevations and the fine stripe at higher elevations. At one site a secondary set of stripes was observed to occur within the fine stripe of a primary larger set. On a trachyte plug there was evidence of lateral squeezing in the formation of the stripes. A number of minor observations pertaining to the possible mechanism of stripe formation are given. 相似文献
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Frost sorting on slopes by needle ice: A laboratory simulation on the effect of slope gradient 下载免费PDF全文
Following a previous attempt to reproduce miniature sorted patterns on a level surface, we report the results of a full‐scale laboratory simulation on frost sorting produced by needle ice activity on inclined surfaces. Four models, with different slope gradients (5°, 7°, 9°, 11°), were designed. Stones 6 mm in diameter placed in a grid covered 20% of the surface of frost‐susceptible water‐saturated soil. These models were subjected to 20–40 freeze–thaw cycles between 10°C and ?5°C in 12 hours. The evolution of surface patterns was visually traced by photogrammetry. Needle ice growth and collapse induced downslope movement and concentrations of stones. A model produced incipient sorted circles on a 5° slope, whereas it resulted in three distinct sorted stripes on a 7° slope. The average diameter or spacing of these forms is 9.7–19.4 cm, comparable to those in the field dominated by diurnal freeze–thaw cycles. Surface parallel displacements of stone markers were traced with motion analysis software. The observed downslope stone displacements agree with those expected assuming that surface soil and stones move by repeated heaving perpendicular to the surface and vertical settlement due to gravity, although the growth of curved needle adds complexity to the overall displacements. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
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