Lechatelierite-bearing microspherules from semicoke hill (KiviõIi, Estonia): contribution to the contamination problem of natural microtetektites

During the course of the last hundred years, microscopic magnetite and glassy spherules of different genesis (extraterrestrial, volcanic, industrial, biogenic, diagenic, explosive, etc.) have often been found in various geological formations. Alongside classical geological methods, research into extraterrestrial and explosive spherules can provide valuable information and facilitates stratigraphical correlations over large areas. Several authors have recently stressed that studies on cosmicand