Abstract Inland notches are elongated half tube indentations that develop on the carbonate rocky cliffs of mountainous zones. Occasionally tufa accumulates within notches as stalactites, drapes and crusts, covering the cavity backwall or floors. In attempt to determine the age of the latest stage of notch formation and calculate the relative rate of slope retreat, U Th dating was used on 16 tufa samples from 2 notches, providing 28 ages. Tufa grow during the time interval between the backwall erosion and visor collapse, and therefore tufa age is an approximation of the timing of the formation of the surface it developed on, i.e. the age of the notch. The oldest known tufa sample is 39.0 ± 10.4 ky (2σ), and the ages of other tufa samples range from 2.1 to 23.3 ky. At the Nahal Oren notch, the present-day backwall formed by the end of the last glacial period (14 to18 ky), whereas the visor in its present form is from the early Holocene (7 to10 ky). The oldest sample was found ~1 m from the backwall, suggesting that backwall retreat rate ranges from 20 to 35 mm/ky. Other samples were deposited 50 to 200 cm from the visor edge, suggesting that slope retreat order of magnitude ranges from 101 to 102 mm/ky. The backwall of the Nesher notch formed between 10 and 14 ky. Our results correspond with the rates of tens of meters per million years, similar to the magnitude of denudation found by previous studies in the Mediterranean zone of Israel. Dating tufa deposits is a good proxy to estimate the rate of erosion in carbonate slope retreat; however, a precautionary approach should be taken, as rock particles from the eroded bedrock might embed within the tufa, affecting the age results. Questionable samples can be identified using Cathodoluminescence (CL) microscopy.

中文翻译：

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根据 Mt. 山上内陆凹口庇护的凝灰岩沉积的年代顺序估计的斜坡退缩率。以色列卡梅尔

摘要 内陆凹口是在山区碳酸盐岩峭壁上发育的细长的半管状凹口。有时，石灰华会以钟乳石、悬垂物和外壳的形式在凹口内堆积，覆盖腔体后壁或地板。为了确定缺口形成的最新阶段的年龄并计算斜坡后退的相对速率，U Th 测年对来自 2 个缺口的 16 块石灰华样品进行了测定，提供了 28 个年龄。灰岩在后壁侵蚀和遮阳板坍塌之间的时间间隔内生长，因此灰岩年龄是它发展的表面形成时间的近似值，即凹口的年龄。已知最古老的凝灰岩样品为 39.0 ± 10.4 ky (2σ)，其他凝灰岩样品的年龄范围为 2.1 至 23.3 ky。在 Nahal Oren 缺口处，由末次冰期结束（14 至 18 ky）形成的现代后壁，而目前形式的遮阳板来自全新世早期（7 至 10 ky）。在距后壁约 1 m 处发现了最古老的样本，这表明后壁后退速率范围为 20 至 35 mm/ky。其他样品沉积在距遮阳板边缘 50 至 200 厘米处，表明斜坡后退的数量级范围为 101 至 102 毫米/ky。Nesher 凹口的后壁形成在 10 到 14 ky 之间。我们的结果与每百万年数十米的速率相对应，类似于先前在以色列地中海地区的研究发现的剥蚀程度。对凝灰岩沉积进行年代测定是估算碳酸盐岩斜坡后退侵蚀速率的一个很好的代表；但是，应采取预防措施，因为来自被侵蚀基岩的岩石颗粒可能嵌入到凝灰岩中，影响年龄结果。可以使用阴极发光 (CL) 显微镜识别有问题的样品。