Duluth Complex apatites age reference material for LA-ICP-MS based fission-track dating
Duluth Complex apatites age reference material for LA-ICP-MS based fission-track dating
复制标题
用于基于 LA-ICP-MS 裂变径迹测年的德卢斯复合磷灰石年龄参考材料
DOI：
10.1111/ter.12393
复制
发表时间：
2019
期刊：
影响因子：
2.4
通讯作者：
Masatsugu Ogasawara
中科院分区：
文献类型：
--
作者：
Hideki Iwano;Tohru Danhara;Takashi Yuguchi;Takafumi Hirata;Masatsugu Ogasawara
美国明尼苏达州杜卢斯杂岩中的斜长系列磷灰石具有高达~ 107 cm-2的高自发裂变径迹密度和~900 Ma的均匀年龄，因此可以基于LA-ICP-MS U分析进行高精度裂变径迹定年。进行了绝对裂变径迹定年、径迹长度测量和化学成分分析，以评估冷却历史，这对年龄参考材料至关重要。对具有缩短轨道长度分布的样品的初步逆模型产生了925 Ma时约100°C的单调冷却历史。当采用涉及5.5 M HNO 3的常用蚀刻方案时，磷灰石会产生过度蚀刻问题。
Anorthositic series apatites of the Duluth Complex, Minnesota, USA, have high spontaneous fission‐track densities of up to ~107cm–2and a homogeneous age of ~900 Ma, allowing high‐precision fission‐track dating based on LA–ICP–MS U analysis. Absolute fission‐track dating, track‐length measurement and chemical composition analysis were performed to evaluate a cooling history, which is essential for age reference materials. Preliminary inverse modelling for a sample with a shortened track‐length distribution yielded a monotonic cooling history from ~100°C at 925 Ma. The apatites incur an over‐etching problem when employing the commonly used etching protocol involving 5.5 M HNO3.