ELECTRON SCANNING MICROSCOPY FOR STUDING MAGNETIC FRACTION OF LAKES SEDIMENTS (SOUTH URAL, RUSSIA)

ABSTRACT

The paper considers the features of the sedimentation of the lakes of the Southern Urals, Bolshoi Kisegach and Turgoyak. Previous studies shows that micrometeorites and cosmic dust can be found in different types of sediments and rocks and also magnetic properties can be used for choosing reliable samples for further investigations. Morphology and elemental composition of 5 magnetic separates studied using scanning electron microscopy in the Interdisciplinary Center for Analytical Microscopy of the KFU on the field emission scanning electron microscope equipped with an energy-dispersive spectrometer. Both lakes contain magnetite microspherules which unevenly distributed along the core. According microscopic investigations of magnetic material of lake sediments are presented by authigenic and allothigenic minerals. Allothigenic component is presented both by extraterrestrial magnetic particles and detrital material (magnetite, chromium magnetite, low-titan magnetite and other ferromagnetic minerals) which were transported to the sedimentation basin by streams and wind.

Keywords: lake sediments, cosmic dust, micrometeorites, scanning electron microscopy