New Insights Into the Proposed Geomagnetic Excursion Hilina Pali From High-Resolution Lake Sediment Cores From the Polar Ural Mountains, Arctic Russia

Abstract

This study presents paleomagnetic records from three 24 m-long sediment cores from the neighboring lakes Bolshoye Shchuch'ye and Maloye Shchuch'ye, located about 10 km apart in the Polar Urals in northern Russia. The age model, based on radiocarbon dating and varve counting, shows that the sediment sequences reach back up to about 23.5 ka cal. BP. Mineral magnetic analyses indicate that the upper sedimentary sequence is not suitable for paleomagnetic analyses. Below about 6.7 m the paleosecular variation and relative paleointensity in the magnetic field in the period 23.6–14.8 ka cal. BP is reconstructed. The magnetostratigraphic results show very similar pattern in both lakes including a directional anomaly previously called the Bolshoye Shchuchye Event. This event is dated to the period 20.2–19.1 ka cal. BP accompanied with a low in relative paleointensity. Comparisons with sediment records from other regions suggest that this paleomagnetic feature represents the proposed Hilina Pali geomagnetic excursion, which is documented in unprecedented high resolution in the studied lakes. The reconstructed path of the virtual geomagnetic field during this event shows that the pole positions remain at latitudes higher than 55°N while describing a clockwise loop. According to varve counts the inclination deviation and virtual geomagnetic pole latitude deviation associated with Hilina Pali lasted 1135 ± 35 years and 1294 ± 44 years, respectively, in northern Russia.