Abstrakt
The onset of the Younger Dryas period is often recognized in sediment as a record of sudden climate cooling and a recent hypothesis considers airbursts as a possible cause. In the layer of sediment from this era there are microspherules composed mostly of iron oxide.
We analyzed sediment from two US sites (Gainey in Michigan, and Blackwater in New Mexico) and one from Europe in the Czech Republic. Microspherules could have formed through atmospheric lightning discharges that melted terrestrial airborne material.
During such discharges, there is a corresponding generation of intense magnetic fields and after the rapid cooling of these spherical particles, high-magnetic characteristics should remain within these particles. We investigated the magnetic characteristics of the microspherules.