Meteoric 10Be as a Tracer of Terrestrial Sedimentary Processes

Meteoric 10Be 作为陆地沉积过程的示踪剂

• 批准号: 55150465
• 负责人: Professor Dr. Friedhelm von Blanckenburg
• 金额: --
• 依托单位: Fachrichtung Geochemie, Hydrogeologie, Mineralogie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/55150465?language=en
• 关键词: Meteoric; 10Be; Tracer; Terrestrial; Sedimentary

The development of terrestrial cosmogenic nuclide applications is currently a dynamic field emerging in the Earth- and Environmental Sciences. Here we propose to explore meteoric 10Be that is produced in the atmosphere and then is deposited into soil. Due to its rapid adsorption onto clays, this nuclide has great potential as a tracer of rates, ages, and provenance in sedimentary processes and long-term soil stability. Prerequisite is calibrating and checking the system. Such a calibration has now become possible and is the aim of this proposal. It includes 1) a calibration of the meteoric flux over the Holocene from well-dated crater lake sediments; 2) an assessment of 10Be retention behavior in soils of which the age is measured by in situ-produced 10Be; 3) a test of potential steady state between 10Be flux into and 10Be export out of a river basin by measuring the 10Be concentration in river sediment which, if steady state is established, would allow for calculation of basin-wide erosion rates. Newly possible applications for this technique include quantifying erosion rates from any sedimentary system even where coarse-grained quartz is unavailable such as sediment sampled from automated stream gauge pumping and sampling stations for modern erosion rates, and lake and offshore core material for quantifying paleoerosion rates. In addition, the savings in sample processing time and the possibility of measuring relatively high 10Be/9Be ratios on the accelerator mass spectrometers to be installed in the coming years are necessary goals for the entire cosmogenic nuclide community.

陆地宇宙成因核素应用的发展目前是地球和环境科学中新兴的一个充满活力的领域。在这里，我们建议探索大气中产生然后沉积到土壤中的流星 10Be。由于其快速吸附在粘土上，这种核素具有作为沉积过程中的速率、年龄和来源以及长期土壤稳定性示踪剂的巨大潜力。先决条件是校准和检查系统。这种校准现已成为可能，也是本提案的目的。它包括 1) 根据已确定年代的火山口湖沉积物对全新世的大气通量进行校准； 2) 对土壤中 10Be 的保留行为进行评估，土壤的年龄是通过原位产生的 10Be 来测量的； 3) 通过测量河流沉积物中的 10Be 浓度来测试流入流域的 10Be 通量和流出流域的 10Be 通量之间的潜在稳态，如果建立了稳态，则可以计算全流域的侵蚀率。该技术的新可能应用包括量化任何沉积系统的侵蚀率，即使是在无法获得粗粒石英的情况下，例如从自动流量计泵和采样站采样的沉积物以测定现代侵蚀率，以及用于量化古侵蚀率的湖泊和近海岩心材料。此外，节省样品处理时间以及在未来几年安装的加速器质谱仪上测量相对较高的 10Be/9Be 比率的可能性是整个宇宙成因核素界的必要目标。