The Upper Pleistocene (Marine Isotope Stage 5e; ca 120 ka) stratigraphic record from the Bahamas comprises large, kilometre‐long parabolic ridges of oolitic composition, that point landward, and have been up to now called ‘chevrons’. A debate about their genesis has led previous researchers to consider two processes of deposition: (i) a catastrophic event involving giant storm‐generated waves produced by specific climatic conditions at the end of Marine Isotope Stage 5e; and (ii) a more uniformitarian process which characterizes ‘chevrons’ as aeolian parabolic dunes because of their similar morphology. Since there are few unequivocal sedimentological criteria to discriminate aeolian from water‐deposited sediments, only a quantitative, multi‐method approach could provide enough evidence to produce a viable diagnosis on the genetic processes involved. Following this reasoning, the quantification of the morphological parameters of ‘chevrons’, a precise study of their sedimentary structures on previously and newly discovered sections, and several statistical grain‐size analyses, all advocate for an aeolian origin. Moreover, when the aforementioned characteristics of ‘chevrons’ are compared with those of storm deposits (for example, washovers) and parabolic dunes occurring elsewhere on Earth, the dissimilarity with the former and the resemblance with the latter is evident. Amino‐acid racemization dating, together with stratigraphic and petrographic investigations, constrain the age of the ‘chevrons’ to the late part of Marine Isotope Stage 5e. Their occurrence during this specific time interval can be explained by both strengthened easterly winds and drier climatic conditions associated with changing vegetation cover. Fixation of the arms by sparse vegetation, coupled with the loose ‘chevron’ nose sediment migrating farther inland, form the peculiar U‐shaped morphology of these ridges.

中文翻译：

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巴哈马的上更新世抛物线脊（即“人字形”）：风暴波沉积物还是风成沉积物？定量方法

上更新世（海洋同位素5e期; ca巴哈马的120 ka）地层记录由大型的，千米长的抛物线脊组成，指向陆面，一直到现在都被称为“人字形”。关于其成因的争论已导致先前的研究人员考虑了两个沉积过程：（i）一场灾难性事件，涉及在海洋同位素第5e阶段结束时由特定气候条件产生的巨大风暴产生的波；（ii）更为统一的过程，由于其形貌相似，因此将“雪佛龙”形容为风成抛物线沙丘。由于几乎没有明确的沉积学标准来区分风沙与水沉积物，因此只有定量，多方法的方法才能提供足够的证据，对相关的遗传过程进行可行的诊断。按照这种推理，“人字形”形态参数的量化，对先前和新发现的剖面上它们的沉积结构的精确研究以及数种统计粒度分析，都倡导了风成因。而且，将上述“人字形”的特征与风暴沉积物（例如冲刷物）和地球上其他地方发生的抛物线沙丘的特征进行比较时，与前者的相似性和后者的相似性显而易见。氨基酸外消旋测年以及地层学和岩石学研究将“人字形”的年龄限制在海洋同位素第5e阶段的后期。它们在此特定时间间隔内的发生可以用东风增强和与植被变化有关的更干燥的气候条件来解释。