Down-core variations of the SIRM for CON01-603-2.

The concentration in ferromagnetic particles is much lower in the interglacial sediments than in glacial sediments. Therefore, the NRM needs to be normalised by a concentration-related parameter, such as κLF, ARM or SIRM, in order to generate relative paleointensity records free of the effects of concentration (Fig. 5). The three intensity records look quite similar in the topmost part of the sedimentary column, but intensity values are lower in the bottom of the column when using κLF or SIRM instead of ARM as a concentration parameter. Low values of ARM/SIRM are also observed in the bottom of the sedimentary column, while SIRM values remain constant. The discrepancies between the relative paleointensity records result from a relative high amount of coarse magnetic grains (high values of SIRM), which lower the intensity carried by small magnetic particles preferentially contributing to the ARM.