Precambrian paleomagnetic studies are critical for testing paleogeographic reconstructions in deep time but rely on the fidelity of the assumption of the geocentric axial dipole (GAD) hypothesis. With high-reliability data from mafic dykes and volcanic rocks, the scatter of individual virtual geomagnetic poles (VGPs) can be used to test simple GAD models. In order to conduct such a test, the VGPs must be adequate in number and in spatial coverage of the sampling sites. In this study, we targeted the 2.1 Ga Indin dyke swarm of the Slave craton. Building on previous sampling of the Indin dyke swarm in the western and central parts of southern Slave craton, we report results from 9 additional sites in the central and eastern parts of the craton, sites that significantly expand the width of the dyke swarm across the entire craton. The VGPs obtained from 7 of 9 newly identified Indin dykes are broadly similar to previously reported directions, expanding the total of VGPs for individual Indin dykes to n = 28, which is sufficient for a test of the GAD-based statistical models using VGP scatter. The high VGP scatter of the Indin swarm can be attributed to the relatively high paleolatitude of 56° ± 6° for the Slave craton at the time of dyke emplacement. The Indin data have VGP scatter that is consistent with field models associated with the GAD hypothesis for the indicated paleolatitude, thus confirming the fidelity of the GAD field at ca. 2.1 Ga.

中文翻译：

---

约 2.1 Ga 的适形可变地心轴向偶极子：Indin Dyke 群的古地磁色散，奴隶克拉通


前寒武纪古地磁研究对于测试深时古地理重建至关重要，但依赖于地心轴向偶极子 （GAD） 假说假设的保真度。借助来自镁铁质岩脉和火山岩的高可靠性数据，单个虚拟地磁极 （VGP） 的散射可用于测试简单的 GAD 模型。为了进行此类测试，VGP 必须在采样点的数量和空间覆盖范围上足够。在这项研究中，我们瞄准了奴隶克拉通的 2.1 Ga Indin 岩脉群。在先前对奴隶克拉通南部西部和中部的 Indin 岩脉群进行采样的基础上，我们报告了克拉通中部和东部的另外 9 个地点的结果，这些地点显着扩大了整个克拉通的堤坝群的宽度。从 9 个新发现的 Indin 岩脉中的 7 个获得的 VGP 与以前报道的方向大致相似，将单个 Indin 岩脉的 VGP 总数扩大到 n = 28，这足以使用 VGP scatter 测试基于 GAD 的统计模型。Indin 群的高 VGP 分散可归因于在堤坝放置时 Slave 克拉通的古纬度相对较高，为 56° ± 6°。Indin 数据具有 VGP 散射，这与与所指示的古纬度的 GAD 假说相关的场模型一致，从而证实了 GAD 场在约 2.1 Ga 时的保真度。