Investigating the duration and termination of the Early Paleozoic Moyero reversed polarity Superchron: Middle Ordovician paleomagnetism from Estonia

Abstract

Ever since their discovery nearly 50 years ago, geomagnetic superchrons have been a puzzle for the geophysical community. Although there have only been a few during Phanerozoic time, Driscoll and Evans (2016) recently proposed multiple superchrons during the Proterozoic. Biggin et al. (2012) suggested that superchrons are the result of low heat flow at the Core Mantle Boundary (CMB), which causes low dynamo activity, and that they are generally separated by 180–190 Myr. According to Courtillot and Olson (2007), one potential process for ending a superchron is via the generation of a superplume at the bottom of the mantle, followed by the eruption of a large igneous province (LIP) 10–20 Myr later. However, this theory is unable to explain the Middle Cretaceous LIP activity and recent modelling favors a longer plume rise-time of 20–50 Myr (Biggin et al., 2012).

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