Precise cross-calibration of 40Ar/39Ar, Rb-Sr and U-Pb chronometers: towards an integrated geochronology toolbox

40Ar/39Ar、Rb-Sr 和 U-Pb 天文钟的精确交叉校准：迈向集成地质年代学工具箱

• 批准号: DP140101116
• 负责人: Dr Yuri Amelin
• 金额: $ 27.66万
• 依托单位: The Australian National University
• 依托单位国家: 澳大利亚
• 项目类别: Discovery Projects
• 财政年份: 2014
• 资助国家: 澳大利亚
• 起止时间: 2014-01-01 至 2017-09-01
• 项目状态: 已结题
• 来源: https://dataportal.arc.gov.au/RGS/Web/Grants/DP140101116
• 关键词: Precise; cross; calibration; 40Ar; 39Ar

Application of the 40Ar/39Ar isotopic geochronometer to dating rocks, minerals, fossils and meteorites is limited by insufficient precision and consistency in existing determinations of the half-life of its parent isotope 40K. This project proposes novel methods for determination of the half-life and branching ratio of 40K, by age comparison against well calibrated 87Rb-87Sr and 40K-40Ca geochronometers. The ages with all isotopic systems will be determined in the same minerals, thus eliminating the main source of uncertainty in the previous studies. Independently The project will measure the 40K decay rate by decay counting of highly enriched 40K salt and expects a five-fold improvement in precision and accuracy of known 40K decay rate.

将40AR/39AR同位素地球运动量应用于约会岩石，矿物质，化石和陨石的限制受到精度和一致性不足的限制，在其父母同位素40K的半衰期中的现有确定中。该项目提出了新的方法，用于确定40K的半衰期和分支比例，这是与校准良好的87RB-87SR和40K-40CA地球运动器的年龄比较。所有同位素系统的年龄将在同一矿物质中确定，从而消除了先前研究中的主要不确定性来源。独立地，该项目将通过对高度富集的40k盐的衰减计数来衡量40k衰减率，并预计已知40k衰变速率的精确度和准确性提高了5倍。