A 4,500-year record of palaeomagnetic secular variation and relative palaeointensity from the Tyrrhenian Sea

Pontus Lurcock1*, Fabio Florindo1,2, Sergio Bonomo3, Antonio Cascella4, Federico Di Rita5, Luciana Ferraro6, Donatella Domenica Insinga6, Donatella Magri5, Giulia Margaritelli7, Nicola Pelosi6, Paola Petrosino8, Mattia Vallefuoco6, Claudia Cosentino9 & Fabrizio Lirer6, 2020, A 4,500-year record of palaeomagnetic secular variation and relative palaeointensity from the Tyrrhenian Sea, Geological Society, London, special publications (Online) (2020). doi_10.1144/SP497-2019-255,
URL: http://www.cnr.it/prodotto/i/423173

A marine sediment core from the western Mediterranean provides a newhigh-resolution 4,500-year record of palaeomagnetic secular variation and relativepalaeointensity. In 2013, the 7.1-metre C5 core was recovered from the TyrrhenianSea as part of the NextData climate data project. The coring site, 15 km offshorefrom the Volturno river mouth, is well-located to record combined marine andterrestrial palaeoclimatic influences, and the fine-grained, rapidly deposited sedimentsare effective palaeomagnetic recorders. We investigate the palaeomagnetic field direction and strength recorded in the core, which provide a valuable high-resolution recordof Holocene geomagnetic variation in the area. Using rock magnetic techniques,we constrain the magnetic mineralogy of the studied sediments and confirm theirsuitability for palaeomagnetic analysis. Palaeomagnetic declination and inclinationrecords were determined by stepwise alternating-field demagnetization, and relativepalaeointensity estimates were obtained based on normalization to anhysterestic andisothermal remanent magnetization and to magnetic susceptibility. The age of the coreis well-constrained with a tephro- and biostratigraphic age model, and its magneticrecords are compared with relevant core and model data for the region, demonstratingthat our record is compatible with previous results from the area. An automated curvematching approach is applied to assess the compatibility of our data with the existingsecular variation path for the Mediterranean area.

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