ИСТИНА

In this report we present the first results of a preliminary cyclostratigraphic study of the Yuryakhian horizon of the Kulyumbe Formation of the Kulyumbe river section and its application to constraint the duration of the SPICE anomaly as well as long interval of the magnetic polarityб both recorded in these sediments [Kouchinsky et al. 2008]. Data on the magnetic susceptibility (MS) of rocks were used as a proxy. MS variations have a distinct cyclic nature, well coinciding with the cyclicity observed in the section, expressed in the color and composition of the rocks. This fact gives grounds to consider MS to be the primary characteristic of sediments. MS, in turn, mainly depends on the concentration and mineralogical composition of iron oxides, which are sensitive to climate change.