Abstract Nearly 40 years ago, Emile Thellier published an article summarizing the archeomagnetic data he had obtained during his career, which had allowed him to recover the main features of the directional variations of the geomagnetic field in France for the last two millennia. This database went on to be significantly completed 25 years ago by Ileana Bucur, who had taken over Thellier's work on archeomagnetism; this forms the current basis of our knowledge of the directional evolution of the geomagnetic field in France. Since then, archeomagnetic studies have been continued at Thellier's historical laboratory in Saint Maur. This article presents the directional archeomagnetic data obtained in France over the past 25 years in this same laboratory. A total of 528 new data are presented, which, together with the 170 results obtained on the French territory previously listed in Bucur (1994) , constitute the French directional database (698 data in all). All but two of these data were obtained using the experimental protocol developed by E. Thellier based on the analysis of large samples and on a magnetic viscosity test that has proved its reliability on numerous occasions. The directions from the entire French database have been precisely defined, with 95% of the α95 values being less than 1.9°, and ~ 50% being less than 0.8°. The selection of 286 data with dating uncertainties of ≤50 years allowed us to compute a new reference directional variation curve for France since the first century BC using sliding windows, the variable durations and shifts of which were adapted to the time distribution of the available data, and the bivariate extension of the Fisher statistics. This shows ample and smooth variations, fairly similar to those previously determined from a much smaller database. The resulting secular variation curve is particularly well suited for use in archeomagnetic dating.

中文翻译：

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经过 25 年的额外数据采集后，法国在过去两千年中更新的古地磁方向变化曲线

摘要 近 40 年前，埃米尔·塞利尔 (Emile Thellier) 发表了一篇文章，总结了他在职业生涯中获得的古地磁数据，这使他能够恢复过去两千年法国地磁场方向变化的主要特征。这个数据库在 25 年前由 Ileana Bucur 完成，他接管了 Thellier 的考古磁学工作。这构成了我们目前了解法国地磁场定向演化的基础。从那时起，考古磁学研究一直在圣莫尔的 Thellier 历史实验室继续进行。本文介绍了过去 25 年来在同一实验室中在法国获得的定向古地磁数据。一共呈现了528个新数据，其中，与之前在 Bucur (1994) 中列出的在法国领土上获得的 170 个结果一起，构成了法国定向数据库（共 698 个数据）。除了两个数据之外，所有这些数据都是使用 E. Thellier 开发的实验协议获得的，该协议基于对大样本的分析和已多次证明其可靠性的磁粘度测试。来自整个法国数据库的方向已被精确定义，95% 的 α95 值小于 1.9°，约 50% 小于 0.8°。选择了 286 个测年不确定度≤50 年的数据，使我们能够使用滑动窗口计算自公元前一世纪以来法国的新参考方向变化曲线，其可变持续时间和偏移适应可用数据的时间分布, 以及 Fisher 统计量的二元扩展。这显示了充足而平滑的变化，与之前从一个小得多的数据库中确定的变化非常相似。由此产生的长期变化曲线特别适合用于古地磁测年。