Magnetic susceptibility application: a window onto ancient environments and climatic variations: foreword

Abstract

Magnetic susceptibility (MS) is a powerful tool, which is being applied increasingly on sedimentary rocks to constrain stratigraphic correlations, or as a palaeo-environmental or palaeoclimatic tool. The origin of the magnetic minerals responsible for the variations in MS can be linked to various phenomena such as detrital inputs, pedogenesis, bacterial precipitation or diagenesis. Therefore, it is critical to improve our knowledge of the origin of the MS signal in order to apply it for correlations or as a proxy. Here, we present a synthesis of the techniques that can be applied to get a better understanding of the origin of the MS signal, through comparison with other palaeo-environmental proxies, through magnetic measurements or through dissolution and direct observation of the extracted minerals. We also propose an overview of the different techniques applied in order to use MS as a correlation tool, and we show various examples of successful applications of MS as a recorder of change in past sea-level and climate. We also present the main results and activities of the IGCP-580 project 'Application of magnetic susceptibility as a palaeoclimatic proxy on Palaeozoic sedimentary rocks and characterization of the magnetic signal'.

Helminth Eggs as a Magnetic Biomaterial: Introducing a Recognition Probe

“…However, the oxygen in the structure of the helminth eggs ( 58 , 59 ) also has attribution in the magnitude of a magnetic field, due to its high magnetic susceptibility ( 60 ). Therefore, the magnetic field originated from this component ( 60 , 61 ) as well as water layers ( 61 ).…”

Magnetic Susceptibility Record in Paleozoic Succession (Rhenohercynian Massif, Northern Europe) – Disentangling Sea Level, Local and Diagenetic Impact on the Magnetic Records

“…Their results suggested the high potential of χ signal for global correlation in ancient sedimentary sequences. Whereas promising, these results lack the geochemical and magnetic basis that are now regarded as crucial prior to any interpretation or use of the χ signal (e.g., Da Silva et al, 2015).…”

“…Despite the remagnetization highlighted in the NE Rhenohercynian Massif and Ardennes (Molina Garza and Zijderveld, 1996;Zwing et al, 2002Zwing et al, , 2005Zegers et al, 2003), Riquier et al (2010) and Da Silva et al (2013) demonstrated that the primary depositionally-induced χ signal was at least partly preserved and that it could be used for paleoenvironmental and paleoclimatic interpretations. Therefore, it is essential to test the origin of the magnetic signal through the combined use of geochemical, facies analyses and hysteresis measurements (Riquier et al, 2010;Da Silva et al, 2015) before applying χ as a paleoclimatic or correlation tool for sections at any scale.…”

Downhole logging data for time series analysis and cyclostratigraphy

“…MS (and other magnetic properties as e.g. the isothermal remanent magnetization) often traces terrigenous input vs. authigenic bioproduction, and MS is a frequently applied and valuable proxy (e.g., Da Silva et al, 2015 and references therein; Table 1). In marine environments, MS generally traces the influx of terrestrial material, and high MS relates to high fluvial or dust influx.…”