Magnetic properties of Arctic sediments: implications for magnetic stratigraphy

University Of Florida, Gainesville FL

Investigators

Abstract

This project hypothesizes that zones of apparently reversed magnetization in Brunhes age sediments in the Arctic Ocean and Greenland-Norwegian Sea are due to self-reversal in the mineral greigite formed as alteration coatings from magnetite. Nine HOTRAX (Healy-Oden Trans-Arctic Expedition, 2005) cores will be studied in order to establish the stratigraphic control on natural remanent magnetization (NRM) component directions from core to core. Thermal demagnetization of NRM determined on Al foil-wrapped discrete sub-samples will help determine the carriers of NRM. Low temperature remanence loss and high temperature hysteresis data will establish the magnetic carriers. SEM (Scanning Electron Microscope) studies and X-ray diffraction of magnetic separates will augment the magnetic measurements. Successful completion of this project will identify a cause of reverse magnetization in Arctic marine sediments, leading to improved age dating of the sediments and correlations and control with global sediments based on magnetostratigraphy. The project will support one graduate student, and also involve undergraduate students in the core analysis.