Relief forms on the surface of cosmogenic spherules as a sign of their origin

Abstract

When studying the material composition of sedimentary formations, the problem of identifying extraterrestrial matter arises, in particular, distinguishing cosmic spherules from technogenic and volcanogenic ones. Based on the results of study of a collection of 482 volumetric spherules separated from ferromanganese crusts from the Pacific Ocean floor, an additional feature of such identification based on relief forms on the surface of spherules is proposed. The article gives a detailed description of such relief forms arising during the passage by cosmic particles through the upper layers of the Earth’s atmosphere, isolation and separation of the Fe-Ni cores from the spherules. The presence of a round hemispherical cavity on the flattened side of the spherule, a depression with concentric circles, or a «button» structure, as well as the presence of a Fe-Ni core is a sufficient but not necessary sign to consider a spherule cosmogenic.