The Arctic Ocean Manganese Cycle, an Overlooked Mechanism in the Anomalous Palaeomagnetic Sedimentary Record

Steffen Wiers,Ian Snowball,Bjarne Almqvist,Christof Pearce,Matt O’Regan

doi:10.3389/feart.2020.00075

Steffen Wiers, Ian Snowball + Show 3 more

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https://doi.org/10.3389/feart.2020.00075

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Abstract

Palaeomagnetic records obtained from Arctic Ocean sediments are controversial because they include numerous and anomalous geomagnetic excursions. Age models that do not rely on palaeomagnetic inter ...

Highlights

The magnetostratigraphy of Arctic Ocean sediments has bewildered geologists because palaeomagnetic studies yield high frequency changes in polarity (e.g., Backman et al, 2004) that do not match the established Geomagnetic Polarity Time Scale (GPTS; Cande and Kent, 1995)
Arctic Manganese and Magnetic Properties as geomagnetic reversals, with the uppermost change in inclination assigned to the Matuyama-Brunhes polarity transition (e.g., Steuerwald et al, 1968; Clark, 1970), which resulted in low sedimentation rate estimates
The lithostratigraphy of core 13PC is similar to other cores from the region, nearby cores ARA03-28A and HLY05038JPC (hereafter 8JPC; Adler et al, 2009; Schreck et al, 2018; FIGURE 4 | Natural remanent magnetisation (NRM) and related parameters

Summary

Introduction

The magnetostratigraphy of Arctic Ocean sediments has bewildered geologists because palaeomagnetic studies yield high frequency changes in polarity (e.g., Backman et al, 2004) that do not match the established Geomagnetic Polarity Time Scale (GPTS; Cande and Kent, 1995). Arctic Manganese and Magnetic Properties as geomagnetic reversals, with the uppermost change in inclination assigned to the Matuyama-Brunhes polarity transition (e.g., Steuerwald et al, 1968; Clark, 1970), which resulted in low sedimentation rate estimates These low rates were later challenged by alternative dating approaches, with the conclusion that the most extreme palaeomagnetic directional changes (in inclination) were records of geomagnetic excursions during the Brunhes chron (e.g., Nowaczyk et al, 1994, 2001; Jakobsson et al, 2000; Nowaczyk and Knies, 2000; Backman et al, 2004). 10 cm/ka that models of natural remanent magnetisation (NRM) acquisition by sediments predict is necessary to record short-term polarity changes, such as geomagnetic excursions (Roberts and Winklhofer, 2004) These difficulties in interpreting palaeomagnetic data in the Arctic led to the exclusion of magnetostratigraphy in the construction of the Arctic Coring Expedition (ACEX, IODP Expedition 302) age model for the Neogene (Backman et al, 2008). While some studies (e.g., Spielhagen et al, 2004) of Arctic Ocean sediments assumed inclination changes to be coeval and used them for stratigraphic correlation, more recent studies that placed inclination changes into the lithostratigraphic context of the Arctic Ocean (e.g., O’Regan et al, 2008; Wiers et al, 2019) have confirmed the abnormal nature of the palaeomagnetic record by showing that inclination changes are not stratigraphically coeval

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