NATIVE IRON IN THE SEDIMENTS OF LAKE BAIKAL (borehole BDP-98): RESULTS OF THERMOMAGNETIC ANALYSIS
D.M. Pechersky, D.M. Gil’manova, E.V. Ivanov, M.I. Kuz’min, G.P. Markov, D.K. Nurgaliev, V.A. Tsel’movich
Keywords: Thermomagnetic analysis, probe microanalysis, sediments, native iron
Abstract
We performed a thermomagnetic analysis of 91 samples and a probe microanalysis of five samples of sedimentary rocks from the lower zone of the borehole BDP-98 drilled at the bottom of Lake Baikal. The results show the scarcity of native iron: It was found only in five samples. Its concentration varies from ~10–5 to 7·10–4 %. The distribution of native-iron concentrations is bimodal, with a distinct “zero” mode. This scarcity of native iron in the Baikal sediments distinguishes them from continental (Eurasia) and oceanic (Atlantic) sediments of different ages. It is due to the high rate of sedimentation in the studied interval of BDP-98.
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