新生代氩-氩年龄标准物质研制

The 39Ar-40Ar dating is widely used in geochronology, deposit chronology, orogenic belt chronology and the young geological system chronology. Reference material is not only essential for obtaining 39Ar-40Ar isotopic age, but also the main factor to affect the quality of the 39Ar-40Ar dating. In order to yield high-precision results of 39Ar-40Ar dating technique, all age data depend on accurate ages of National Standard Reference Materials that were irradiated together with unknown samples in a neutron reactor. In order to eventually obtain accurate 39Ar-40Ar age, it’s necessary to develop reference materials with different age values..This application is based on the pre-development work, indoor research met the requirements of the national first-grade technical specification for standard materials as JJG1006-1994. Our study aimed to apply for our sample as National certified reference material (CRF). The main research include four aspects: the homogeneity tests of sample, the stability tests of sample, through Ar-Ar analysis from Several laboratories and obtain certified value. The development of Cenozoic Reference Material for Ar-Ar dating can be the first CRMs of Cenozoic for Ar-Ar in China.

氩-氩定年因其测试对象广，年龄测定范围宽，封闭温度覆盖区间大等特点，现今已成为区域地质年代学、矿床年代学、造山带年代学和年轻地质体系年代学研究中最重要的方法。标准物质不仅是获得氩-氩同位素年龄所必不可缺少的，也是影响氩-氩同位素年龄数据质量的主要因素。.本申请研制的新生代氩同位素年龄标准物质是在前期研制工作的基础上，按照国家一级标准物质技术规范（JJG1006-1994）要求，继续开展对样品的均匀性检验、稳定性检验，通过多家实验室定值方式，最终确定标准物质的标准值并申请国家有证标准物质。此次研制的新生代氩-氩年龄标准物质将填补我国缺少新生代地质样品氩同位素定年有证标准物质的空缺。

氩-氩定年标准物质不仅是获得氩-氩同位素年龄所必不可缺少的，也是影响氩-氩同位素年龄数据质量的主要因素。课题组研制的新生代氩同位素年龄标准物质是在前期研制工作的基础上，按照国家一级标准物质技术规范（JJG1006-1994）要求，继续开展对样品的均匀性检验、稳定性检验，通过多家实验室定值方式，最终确定标准物质的标准值。通过研究取得了以下进展：（1）经过大量Ar-Ar年龄分析测试检验分析，确定了SK01透长石样品是均匀的，为氩年龄标准物质研制提供了理论支持；（2）在资助期内数次进行稳定性检验分析，证明了SK01透长石样品性状稳定，适宜长期保存和使用，为定值分析提供了依据；（3）获得了数十个有效定值数据，最终确定了氩同位素定年分析标准物质的特性量值Ar-Ar年龄的标准值和不确定度，标准值表达为：t = 27.60 士 0.58 Ma (2σ)；（4）研制成功了新生代氩同位素定年标准物质，填补了我国在这一研究领域的空白，所研制的标准物质量可供我国所有的Ar-Ar法同位素定年实验室使用数十年。在项目执行期间，已发表项目标注的国内SCI论文1篇，并参加1次国内学术会议交流活动。