Institut de Physique du Globe de Paris (IPGP), Sorbonne Paris Cité-Université Paris Diderot, UMR 7154 CNRS, 1 rue Jussieu, 75238, Paris, Cedex 05, France.
Sci Rep. 2018 Jul 5;8(1):10147. doi: 10.1038/s41598-018-28384-z.
Paleomagnetic directional data were obtained from fourteen 0 to 2 Ma old lava flows at Basse-Terre Island (Guadeloupe, French West Indies). Five reversed polarity flows are consistent with their Matuyama age between 1.6-1.5 Ma and 875-790 ka while the ages of the other nine normal polarity units tie them to the Olduvai subchron and the Brunhes Chron. These directions have been combined with previous results obtained from Basse-Terre Island. The overall mean direction (D = -1.2°, I = 31.4°, α = 3.3°) obtained from the 39 non-transitional flows from Basse-Terre Island is indistinguishable from the expected geocentric axial dipole value (D = 0°, I = 29.8°). The dispersion measured from the angular standard deviation of the Virtual Geomagnetic Poles (VGPs) was found to be close to, but smaller than the predictions of geomagnetic models. Together with further directions from the nearby Martinique Island, the 45 directions obtained within the Brunhes chron provide the most robust estimate of the statistical distribution of paleosecular variation (PSV) at this latitude. The sequence of directions shows episodes of high amplitude secular variation that are coeval with several geomagnetic events including the last reversal documented by five transitional directions. Finally, three lava flows have recorded a transitional behavior which could be link to two excursions, the Laguna del Sello (at ~340 ka) and the Pringle Falls (at ~210 ka) events.
从瓜德罗普岛（法属西印度群岛）的 14 个 0 到 2 百万年的熔岩流中获得了古地磁方向数据。五个反转极性流与它们的马修马年龄在 1.6-1.5 百万年和 875-790 千年前一致，而其他九个正常极性单元的年龄则将它们与奥杜瓦伊子时和布容时联系起来。这些方向与以前从巴斯特尔岛获得的结果相结合。从巴斯特尔岛的 39 个非过渡流中得出的总体平均方向（D=-1.2°，I=31.4°，α=3.3°）与预期的地心地轴向偶极值（D=0°，I=29.8°）无法区分。从虚拟地磁极点（VGP）的角度标准偏差测量得到的分散度接近，但小于地磁模型的预测。加上来自附近马提尼克岛的进一步方向，在布容时内获得的 45 个方向提供了该纬度古地磁变化（PSV）统计分布的最可靠估计。方向序列显示出高幅度地磁变化的时期，与包括五个过渡方向记录的最后一次反转在内的几个地磁事件同期。最后，三个熔岩流记录了过渡行为，这可能与两次偏移有关，拉古纳德尔塞洛（约 340 千年前）和普林格尔瀑布（约 210 千年前）事件。
