Abstract The southern Nullarbor Plain is covered by low amplitude (generally 1–2 m) parallel ridges and swales with variable wavelength (300–900 m). The ridges are stony; the swales hold thin deposits of unconsolidated silt and clay. The ridges and swales have previously been attributed to joint control but are not parallel to joints exposed in cave roofs. Instead, they have a striking similarity to central Australian linear sand dunes: they are parallel, regularly spaced and most importantly, fork in a consistent direction. They are here explained as the etched footprints of an extensive linear dune system that once covered much of the southern Nullarbor. Rainwater collecting in the troughs between the sand dunes dissolved the underlying limestone to produce the swales. Recognition of this dune field fills a major gap in the distribution of linear dunes across Australia. The dunes have subsequently disappeared, apart from red aeolian sand in dolines in the southeastern part of the Nullarbor; most of the sand was probably blown offshore. The ridge and swales are oriented predominantly north-south in the west, and northeast-southwest and northwest-southeast in the centre and east, due to deposition by northerly and westerly winds respectively, as shown by directions of forking. The north-south Nullarbor dunes are probably older and may have been deposited in the arid climate of the late Neogene; this would make them the oldest linear dunes in Australia, remnants of an early phase of linear dune activity that has been removed or overprinted elsewhere. The change in wind direction shown by the dune orientation could represent northward migration of sub-tropical high-pressure systems during the late Neogene.

中文翻译：

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纳拉伯平原蚀刻的线性沙丘；澳大利亚南部上新世-更新世风模式的记录

摘要 南部纳拉伯平原被低振幅（一般为 1-2 m）平行的脊和波长可变（300-900 m）的洼地所覆盖。山脊是石质的；洼地拥有薄薄的松散淤泥和粘土沉积物。山脊和洼地以前曾被归因于联合控制，但与洞穴顶部暴露的接缝并不平行。相反，它们与澳大利亚中部的线性沙丘有着惊人的相似之处：它们是平行的、有规律的间隔，最重要的是，它们在一致的方向上分叉。它们在这里被解释为曾经覆盖纳拉伯南部大部分地区的广泛线性沙丘系统的蚀刻足迹。收集在沙丘之间的槽中的雨水溶解了下面的石灰岩，形成了洼地。对该沙丘区域的识别填补了澳大利亚线性沙丘分布的主要空白。除了纳拉伯东南部漏斗中的红色风积沙外，沙丘随后消失了。大部分沙子可能被吹到了海上。山脊和洼地西部主要呈南北走向，中部和东部呈东北—西南和西北—东南走向，分别受北风和西风的影响，如分叉方向所示。南北向的 Nullarbor 沙丘可能更古老，可能沉积在新近纪晚期的干旱气候中；这将使它们成为澳大利亚最古老的线性沙丘，是早期线性沙丘活动的残余物，已在其他地方被移除或覆盖。