An initial case study to deconvolve natural remanent magnetization of a continuous paleomagnetic sample using the software UDECON

Abstract

Previous studies have compiled relative paleointensity data for the last 2–3 Ma from individual paleomagnetic records obtained from marine sediment cores. These records have mostly been obtained by pass-through measurements, which are known to smooth and alter magnetic signals. Among many efforts, a standalone open-use graphical software UDECON has been developed to deconvolve pass-through measurement data. As an initial case study to assess the applicability of the software to deconvolve natural remanent magnetization (NRM) of a continuous paleomagnetic sample, we chose 40 discrete samples from a piston core recovered in the northeast Pacific. We measured NRMs after alternating field demagnetization at 20 mT for both discrete samples and a simulated continuous sample, made by connecting the discrete samples. The discrete samples show centimeter-scale variations in NRM. Such variations are smoothed out and mostly disappear in the results of the simulated continuous sample. However, after using the software to deconvolve the data, the variations are almost completely restored. Good agreement between the discrete sample data and the deconvolved data indicates that the deconvolution by the software is very successful. We observe detailed features of a directional reversal in the data from the discrete samples and in the deconvolved data but not in the data from the simulated continuous sample. This emphasizes that the deconvolution analysis by the software is a powerful tool to extract detailed features from continuous paleomagnetic records obtained by pass-through measurements.