Magnetic spherules from Recent fluvial sediments in Alberta, Canada: characteristics and possible origins

Abstract

Magnetic spherules were recently recovered in recent fluvial sediments in Alberta, Canada, and have been studied using X-ray diffraction, electron microprobe, scanning electron microscope, and neutron activation analysis. Results show that these spherules are composed of magnetite, wüstite, and hematite; some of them contain α-iron metal cores. The similarities in morphology, mineralogy, and internal structure of these spherules to spherules of extraterrestrial origin found in other environments suggest that some of these spherules from Alberta might also be of extraterrestrial origin, in spite of their unusual compositions.