Lake sediments in volcanic regions contain continuous records of past eruptions and their environmental consequences. However, the frequent scarcity of plant material in lake sediments makes it difficult to provide robust age estimates. In this study, we performed compound‐specific radiocarbon analysis (CSRA) of fatty acids in a sediment core from Lake Kawaguchi in the Mount Fuji volcanic region, Japan, to assess their potential for dating sediments. The C₁₆ fatty acid in the core top sediments exhibits an almost identical age (983 ± 56 years BP) to that of dissolved inorganic carbon in the modern lake surface water, which confirms that the carbon of this compound is derived from lake phytoplankton. Comparison of the ¹⁴C age between the C₁₆ fatty acid and a plant leaf at the widespread (Amagi‐Kawagodaira) tephra layer revealed a lake reservoir age of 1,003 ± 73 ¹⁴C years at ca. 3,150 cal BP, which is consistent with the modern lake reservoir age and the ¹⁴C age of the C₁₆ fatty acid in the core top sediments, within error. The reservoir‐corrected ¹⁴C age of the C₁₆ fatty acid yielded a modeled age of 2,837 ± 78 cal BP for the Mount Fuji Tephra (Omuro scoria‐fall deposit) in the core. This age is in good agreement with the age determined from plant remains in the same core (2,938 ± 29 cal BP), indicating that CSRA of C₁₆ fatty acid has the potential to date lake sediments after reservoir age correction, even in sediments with limited occurrence of plant macrofossils.

中文翻译：

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利用C16脂肪酸的化合物特异性14C分析对湖泊沉积物进行测年：以日本富士山火山区为例

火山区的湖泊沉积物连续记录了过去的火山喷发及其对环境的影响。然而，湖泊沉积物中植物材料的频繁缺乏使得难以提供可靠的年龄估计。在这项研究中，我们对日本富士山火山区川口湖沉积物中岩心中的脂肪酸进行了化合物的特定放射性碳分析（CSRA），以评估它们对沉积物进行年代测年的潜力。核心顶部沉积物中的C ₁₆脂肪酸的年龄与现代湖泊地表水中溶解的无机碳的年龄几乎相同（983±56岁BP），这证实了该化合物的碳源自湖泊浮游植物。C ₁₆与¹⁴ C年龄的比较广泛的（Amagi-Kawagodaira）Tephra层中的脂肪酸和植物叶片显示，湖水库的年龄为1,003±73 ¹⁴ C年。3,150 cal BP，与现代湖泊水库年龄和岩心顶部沉积物中C ₁₆脂肪酸的¹⁴ C年龄相符，均在误差范围内。经过储层校正的C ₁₆脂肪酸的¹⁴ C年龄，岩心的富士山Tephra（Omuro scoria-fall沉积物）的模拟年龄为2837±78 cal BP。该年龄与植物残存在同一核中的年龄（2,938±29 cal BP）高度吻合，表明CSRA为C ₁₆ 脂肪酸在储层年龄校正后有可能使湖泊沉积物过时，即使在植物大型化石发生率有限的沉积物中也是如此。