Magnetostratigraphy and Paleoproductivity of Late Holocene Marine Sediments in the Eastern Bransfield Basin, Antarctic Peninsula

Abstract

During the 9th (1995-1996) KARP (Korean Antarctic Research Program) Expedition, a laminated diatom-rich sediment core (A9-EB2) was obtained from the eastern Bransfield Basin, Antarctic Peninsula region. Total organic carbon (TOC) and magnetic susceptibility (MS) in the core sediments clearly record the oscillation of depositional conditions. In particular, the high-resolution MS variation is a distinct feature to differentiate the high MS values for terrigenous (low TOC) hemiperagic part from the low values for biogenic pelagic (high TOC) part. In contrast to the anoxic condition under which the deep-sea laminated structures in the Santa Barbara Basin can be preserved completely without the obliteration by active bioturbation, the oscillatory MS feature in the Bransfield Basin may be attributed to the climatically-forced and enhanced productivity cycles and less dilution of terrrigenous particles. In spite of poor chronology due to the lack of available data as well as some contaminated datings, the core A9-EB2 shows the cyclic pattern of paleoproductivity in terms of MS signals which has been maintained in the Bransfield Basin, Antarctica during the late Holocene.