Other language confidence: 0.7836821308002652
No significant HIRM change is observed at the transition between oxidising and reducing conditions in the sediment (Fig. 9A). This implies that HIRM is not affected by redox conditions and further confirms that the “hard” magnetic mineral content is the best tracer of detrital input (Peck et al., 1994). On the other hand, the S-ratio seems to be related to the redox conditions in the sediment (see Section 7.2). The ARM has also to be considered with caution as it is mainly influenced by the ferrimagnetic contribution, which is itself influenced by post depositional processes. This is seen in Fig. 9 where ARM variations are partly influenced by S-ratio variations.
Conceptual intercorrelation between ARM and simplified lithology and correlation to the δ18O record from ODP Site 677 (Shackleton et al., 1990), assuming that clay-rich layers with high magnetic concentration represent glacial periods, and that diatomaceous layers with low magnetic concentration represent interglacial periods. Numbers in the δ18O record represent marine isotope stages (MIS).
Anhysteretic remanent magnetisation (ARM) measurements, free of the effect of the dia-, para- and superparamagnetic components, provide an estimation of the magnetic remanence carriers, mainly of single-domain (SD) grain size. The clay-rich layers are characterised by a high, the daitomaceous layers by a low ARM level.