Determining geological provinces in Mediterranean Sea sediment core samples using magnetic susceptibility of sapropels and volcanic ash

摘要

Eight bottom sediment core samples form the Mediterranean Sea, which comprise a total of 136 subsamples, have been collected by the Naval Oceanographic Office and analyzed for their magnetic susceptibility (MS), grain size, and other physical properties. Six cores contain one or more sapropels, and cores 7 and 8 contain three unique sapropels. Six cores contain discrete volcanic ash layers. MS measurements, taken at a depth resolution of 3 cm, range from 66 to 227 SI units within the sapropel layers, whereas the average MS for the entire cores is over 450 SI units. Volcanic ash layers have MS measurements that range from 727 to 910 SI units. These values are probably consistent with the proportion of iron-bearing minerals contained within the respective layers. Anomalous MS values are not precisely aligned with the corresponding sedimentary deposit, possibly due to sensitivity issues with the MS loop. Modeling MS data allows identification of sapropels and volcanic ash layers and provides core-to-core correlation and provincing when combined with additional geophysical data.