Mary Murray

Full vector geomagnetic field variations through the Paleogene

Name: Mary Murray
Primary Supervisor: Prof. Andy Biggin
Year: 3/4
Discipline: Earth Science
Presentation type: 6 min talk
Project Title: Full vector geomagnetic field variations through the Paleogene

Abstract:

What can the history of Earth’s magnetic field tell us about long term changes deep in Earth’s core? The British Paleogene Igneous Province records the paleomagnetic field at a key period in Earth’s history when it had returned to a reversing state. We present new paleointensity and paleomagnetic directional results from a Palaeocene basaltic dyke swarm in Skye (NW Scotland). We also use a phenomenological model of TRM in non-ideal assemblages to predict Arai plots for multidomain specimens and outline a novel inversion method for estimating paleointensity. Our findings highlight the importance of laboratory field orientation as a major control on Arai plot shape. Both the conventional and inversion results are notably weaker than the long-term average and the more recent field, as well as estimates derived from other rocks formed as part of the North Atlantic Igneous Province but they have a similar direction.