Meteoric 7Be and 10Be as Process Tracers in the Environment
Meteoric 7Be and 10Be as Process Tracers in the Environment
复制标题
流星 7Be 和 10Be 作为环境中的过程示踪剂
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
M. Baskaran
中科院分区：
文献类型：
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作者：
J. Kaste;M. Baskaran
7Be（T1/2 = 53 天）和 10Be（T1/2 = 1.4 Ma）通过大气中的自然宇宙发生反应形成，并通过湿和干沉积输送到地球表面。这些放射性核素的独特来源和对土壤、植被、水域、冰和沉积物的近乎恒定的沉降使其成为在数周至数百万年的时间尺度上运行的各种环境过程的宝贵示踪剂。铍易于与氧原子形成牢固的键，因此 7Be 和 10Be 能快速吸附到陆地和海洋环境中的有机和无机固相中。因此，铍的宇宙成因同位素可用于量化土壤、溪流、湖泊和海洋中的表面年龄、沉积物来源、混合率以及颗粒停留和运输时间。然而，对于这些放射性核素作为环境中示踪剂的一般应用，存在许多警告，因为并不能保证所有系统中的稳定沉积和地球化学固定性。在这里，我们综合并回顾了记录这些核素在地球表面的沉积和行为的科学文献，重点关注地球科学家在量化陆地和海洋过程方面的当前和潜在应用。
7Be (T1/2 = 53 days) and 10Be (T1/2 = 1.4 Ma) form via natural cosmogenic reactions in the atmosphere and are delivered to Earth’s surface by wet and dry deposition. The distinct source term and near-constant fallout of these radionuclides onto soils, vegetation, waters, ice, and sediments makes them valuable tracers of a wide range of environmental processes operating over timescales from weeks to millions of years. Beryllium tends to form strong bonds with oxygen atoms, so 7Be and 10Be adsorb rapidly to organic and inorganic solid phases in the terrestrial and marine environment. Thus, cosmogenic isotopes of beryllium can be used to quantify surface age, sediment source, mixing rates, and particle residence and transit times in soils, streams, lakes, and the oceans. A number of caveats exist, however, for the general application of these radionuclides as tracers in the environment, as steady deposition and geochemical immobility are not guaranteed in all systems. Here we synthesize and review scientific literature documenting the deposition and behavior of these nuclides at the Earth’s surface, focusing on current and potential applications for Earth scientists working to quantify terrestrial and marine processes.