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>Character, Rates, and Environmental Significance of Holocene Dust Accumulation in Archaeological Hilltop Ruins in the Southern Levant
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Character, Rates, and Environmental Significance of Holocene Dust Accumulation in Archaeological Hilltop Ruins in the Southern Levant
Loess accumulated in the Negev desert during the Pleistocene and primary and secondary loess remains cover large parts of the landscape. Holocene loess deposits are however absent. This could be due low accumulation rates, lack of preservation, and higher erosion rates in comparison to the Pleistocene. This study hypothesized that archaeological ruins preserve Holocene dust. We studied soils developed on archaeological hilltop ruins in the Negev and the Petra region and compared them with local soils, paleosols, geological outcrops, and current dust. Seven statistically modeled grain size end-members were identified and demonstrate that the ruin soils in both regions consist of mixtures of local and remote sediment sources that differ from dust compositions deposited during current storms. This discrepancy is attributed to fixation processes connected with sediment-fixing agents such as vegetation, biocrusts, and/or clast pavements associated with vesicular layers. Average dust accretion rates in the ruins are estimated to be ~0.14 mm/a, suggesting that ~30% of the current dust that can be trapped with dry marble dust collectors has been stored in the ruin soils. Deposition amounts and grain sizes do not significantly correlate with wind intensity. However, precipitation may have contributed to dust accretion. A snowstorm in the Petra region delivered a significantly higher amount of sediment than rain or dry deposition. Snowfall dust had a unique particle size distribution relatively similar to the ruin soils. Wet deposition and snow might catalyze dust deposition and enhance fixation by fostering vegetation and crust formation. More frequent snowfall during the Pleistocene may have been an important mechanism of primary loess deposition in the southern Levant.
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机译：在更新世期间，内盖夫沙漠中积累的黄土和主要和次生黄土仍覆盖了大部分景观。然而，没有全新世的黄土沉积物。与更新世相比，这可能是由于较低的蓄积率，缺乏保存和较高的侵蚀率。这项研究假设考古遗址保留了全新世的尘土。我们研究了在内盖夫和佩特拉地区的考古山顶遗址上发育的土壤，并将其与当地土壤，古土壤，地质露头和目前的尘土进行了比较。确定了七个统计模型化的晶粒尺寸末端成员，它们表明这两个地区的废墟土壤均由本地和偏远的沉积物源混合物组成，这些沉积物源不同于当前风暴中沉积的粉尘成分。这种差异归因于与泥沙固定剂（例如植被，生物结皮和/或与囊泡层相关的铺面路面）相关的固定过程。废墟中的平均粉尘积聚率估计为〜0.14 mm / a，这表明可用干大理石集尘器捕集的当前灰尘中约有30％已存储在废墟土壤中。沉积量和晶粒尺寸与风强度没有显着相关。但是，降水可能会导致灰尘积聚。佩特拉地区的暴风雪比雨水或干沉降沉积的泥沙量要多得多。降雪粉尘具有独特的粒径分布，与废墟土壤相对相似。湿的沉积物和雪可能会通过促进植被和结皮的形成而促进粉尘的沉积并增强固色效果。在更新世期间更频繁的降雪可能是黎凡特南部初级黄土沉积的重要机制。
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