Magnetic properties of Arctic sediments: implications for magnetic stratigraphy

该项目假设，在北冰洋和格陵兰-挪威海的布鲁赫斯时代沉积物中，磁化明显逆转的区域是由于由磁铁矿蚀变涂层形成的矿物灰长岩的自反转。研究了9个HOTRAX （Healy-Oden Trans-Arctic Expedition, 2005）岩心，以建立岩心间自然剩余磁化（NRM）分量方向的地层控制。在铝箔包裹的离散子样品上测定NRM的热退磁，有助于确定NRM的载流子。低温残余损耗和高温迟滞数据将建立磁载流子。扫描电子显微镜（SEM）研究和磁分离物的x射线衍射将增加磁测量。该项目的成功完成将确定北极海洋沉积物中反磁化的原因，从而改进沉积物的年龄测定，并根据磁地层学与全球沉积物进行对比和控制。该项目将支持一名研究生，并让本科生参与核心分析。

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.