Field Museum researchers find previously unknown type of meteorite

Thu, 06/26/2014 - 10:52 -- pheck

Field Museum researchers co-author a paper on a previously unknown type of meteorite that was found fossilized in a 470 million year old seabed.

Most of the knowledge about the origin and evolution of the Solar System is based on the study of meteorites that are found on Earth’s surface. However, Earth’s ancient seafloors, preserve a record of extraterrestrial matter throughout Earth’s history. Studies of this are very limited to a few events in the past. The Field Museum’s Research Associate Dr. Birger Schmitz (Professor of Geology at Lund University in Sweden), the Robert A. Pritzker Associate Curator for Meteoritics and Polar Studies Dr. Philipp Heck and co-authors from different research institutions reach into a 470-million-years-old window in deep time. Previous research found that the type of meteorites that reached us then was strikingly different than what it is today, and consistent only of one particular meteorite type, ordinary chondrites of with low iron contents (L chondrites).
Now, for the first time ever, the team report the discovery of a different type of meteorite in an ancient 470 million-year-old seafloor in Sweden. It is of a type that is not present in any collection on Earth. On top of that this new meteorite might be a piece of the projectile that shattered into pieces the parent asteroid of the L chondrites in the biggest asteroid collision that occurred in the last 3 billion years that we know of. All of the about 100 meteorites found in these old sediments are fossilized. The Field Museum just received four of those extremely rare and spectacular fossil meteorites and will place them on public display at the end of the year. The Field Museum is the only place in the Western hemisphere where fossil meteorites are housed and will be exhibited. More information on this exclusive exhibit will be made public in the fall. The paper was published in the peer-reviewed journal Earth and Planetary Science Letters and can be found at the following link: http://www.sciencedirect.com/science/article/pii/S0012821X14003367

The exhibit announcement was featured widely in the news media such as in the Chicago Tribune, WGN Radio, and HuffPost among others.

Cross section of a fossil meteorite of the ordinary (L) chondrite type with cephalopod fossil that will be on display at the Field Museum by the end of 2014.