Magnetofossils: Relicts and Records of Deep Time and Space

Magnetofossils are magnetic nanoparticles that represent the fossil remains of microorganisms that biomineralize magnetic minerals in a genetically controlled manner. Most magnetofossils found in the geologic record are produced by magnetotactic bacteria, which use them for navigating within their living environment. Magnetofossils can be identified using a combination of magnetic and imaging techniques. A common attribute of magnetofossils, although not pervasive, is that they are arranged in chains, which determines their specific magnetic properties. Magnetofossil signatures have been reported from ancient rocks to modern sediments and even in extraterrestrial materials. They provide a window into biomineralization, past environments, and ancient magnetic fields, as well as supplying fuel for questions on the origin of life in the Solar System.