MI2021 - 13 Adrian Muxworthy: First palaeomagnetic data from Bleiksmýrardalur (2.5-3.2 Ma), Iceland
Channel: MagNetZ
Date: 2021-02-18

First palaeomagnetic data from Bleiksmýrardalur (2.5-3.2 Ma), northern Iceland

Adrian Muxworthy, Imperial College London, UK

The geocentric axial dipole (GAD) hypothesis states that when we average the geomagnetic field over sufficient time intervals, the time-averaged field (TAF) behaves like a dipole aligned along the Earth’s spin axis and positioned at the Earth’s centre. This hypothesis is crucial in palaeomagnetic research such as palaeosecular variation, palaeoclimate and plate tectonic reconstruction. However, the time interval to average the field to achieve a GAD is still debated. For example, there is some evidence for the persistence of long-term hemispheric asymmetry on time scales of 105-106 yr, particularly at high-latitudes. As most palaeomagnetic research is conducted under the GAD hypothesis, the hypothesis needs to be rigorously tested. As part of a larger study, we have collected and measured samples from various valleys in northern Iceland, to quantify GAD deviations at high-latitudes.In this latest study we report the first results from Bleiksmýrardalur, a remote northern valley with limited access. I will be presenting the full-vector palaeomagnetic data from this valley, which is now complete, however, the overall study is still a work in progress, as we are expecting the Ar/Ar dates from SUERC in the next few months.