| 引用本文: | 杜丁丁,张成君,李志文.中国新疆博斯腾湖现代碳库效应研究.湖泊科学,2024,36(4):1279-1288. DOI:10.18307/2024.0463 |
| Du Dingding,Zhang Chengjun,Li Zhiwen.The effects of modern 14C pool in Lake Bosten, Xinjiang, China. J. Lake Sci.2024,36(4):1279-1288. DOI:10.18307/2024.0463 |
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| 摘要: |
| 碳库效应存在影响了14C测年的准确性,制约了沉积物在湖泊研究中的应用。本文研究位于典型西风环流带的新疆博斯腾湖现代碳库效应,结合同位素地球化学、水化学等方法,探讨了博斯腾湖碳库效应的影响机制。研究结果表明,博斯腾湖最大现代碳库年龄为3535年,最小为现代碳,集中在670~945年。而过去碳库效应集中在1033~2200年。深水区表现为碳库年龄较小且稳定;在入湖口碳库效应最大,富水生植物浅水区碳库效应最小。与过去碳库年龄相比较,现代碳库效应整体表现更为年轻。研究发现,博斯腾湖口受流域外源“死”碳影响,深水区受湖水与大气CO2交换率差异影响,富水生植物浅水区可能受水生植物光合作用影响。此外,核爆效应也对博斯腾湖现代碳库效应产生了影响,可能导致最高约1000年的年代误差。利用深水区放射性碳比活度(pMC)平均值与大气碳比活度差值(~18%),得出深水区沉积物存在约846年现代碳库效应,再经核爆效应校正后得出博斯腾湖存在最高约1800年碳库效应。 |
| 关键词: 博斯腾湖 现代碳库效应 变化规律 影响因素 |
| DOI：10.18307/2024.0463 |
| 分类号: |
| 基金项目:江西省大气污染成因与控制重点实验室开放基金(AE2105)资助。 |
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| The effects of modern 14C pool in Lake Bosten, Xinjiang, China |
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Du Dingding1,2, Zhang Chengjun2, Li Zhiwen3
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1.School of Earth Sciences, East China University of Technology, Nanchang 330013, P. R. China;2.School of Geological Sciences and Mineral Resources, Lanzhou University, Lanzhou 730000, P. R. China;3.School of Environmental and Chemical Engineering, Foshan University, Foshan 528000, P. R. China
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| Abstract: |
| The effects of 14C pool are highly concerned because it affects the accuracy of 14C dating that limits the use of sediment in lake studies. However, the 14C cycling mechanisms are still debating, largely due to a lack of investigation into the effects of modern 14C pool. Lake Bosten in Xinjiang, situated in a typical westerly circulation zone, has high sediment concentration, and is an ideal location to study this issue due to its significant effect of 14C pool. However, previous studies on Lake Bosten mainly focused on past effects of 14C pool, heavily influenced by sediment processes. This study aimed to investigate the effect of modern 14C pool for typical surface sediments of freshwater in Lake Bosten. By combining 14C dating results with isotopic geochemistry, hydrochemistry, and other methods, the study determined that the maximum modern carbon pool age in Lake Bosten was 3535 years, and the minimum was 670-945 years. Past carbon pool effects were concentrated between 1033-2200 years. The deepwater area exhibited a smaller and more stable carbon pool age, while the carbon pool effect was highest in the lake inlet and lowest in the shallow water area with abundant aquatic plants. Compared with the past carbon pool age, the modern carbon pool effect was generally younger. The study found that the Lake Bosten inlet was influenced by external "dead" carbon, the deepwater area was impacted by differences in the exchange rate of lake water and atmospheric CO2, and the shallow water area with abundant aquatic plants may be affected by photosynthesis of aquatic plants. Additionally, nuclear explosion effects also influenced the modern carbon pool effect of Lake Bosten, leading to a potential age error of approximately 1000 years. Finally, by correcting the difference between the average pMC value of the deepwater area and the atmospheric carbon activity (about 18%), the study determined that the deepwater sediment in Lake Bosten has a modern carbon pool effect of about 846 years, which was further corrected for nuclear explosion effects to determine that the highest 14C pool effect in Lake Bosten is about 1800 years. |
| Key words: Lake Bosten effects of modern 14C pool variation rules influencing factor |
