Preliminary rock magnetic and paleomagnetic results from a marine sediment core

We report preliminary results of lithology, rock magnetic and paleomagnetic studies of a short sediment core collected from the ocean bottom during Litoral Bonaerense V Scientific cruiser (Servicio de Hidrografía Naval) during 2012. A short core (135 cm) was collected using a piston core at 100 m water depth. Measurements of intensity and directions of Natural Remanent Magnetization (NRM), magnetic susceptibility, isothermal remanent magnetization, saturation isothermal remanent magnetization (SIRM), back field and anhysteretic remanent magnetization at 100 mT (ARM) were performed and several associated parameters calculated (ARM/k and SIRM/ARM). Also, as a first estimate of relative magnetic grain-size variations, the median destructive field of the NRM (MDFNRM), was determined. The stability of the NRM was analyzed by alternating field demagnetization. The magnetic properties have shown variable values, showing changes in both grain size and concentration of magnetic minerals. It was found that the main carrier of remanence is carried by coarse-grained magnetite grains.