Saturday, February 20, 2016
An interesting video produced by The Field Museum of Chicago, Illinois, USA is on YouTube about Fossil Meteorites. These objects fell to Earth and landed in an ancient sea. Over time like organic fossils there composition changed as the original material was replaced with minerals. The meteorite shown in this video was L chondrite and the chromite composition was measured to identify it.
They dated it by looking at cosmogenic nuclides. As the material traveled through space it was impacted by cosmic rays. This interaction caused the composition to change. By measuring the amounts of certain elements, the approximate age can be determined of the specimen.
The video states the meteorite was found in the Ordovician layer of a quarry in Sweden. I wonder if meteorites that fell during that period can be found in the Louisville area? Maybe the ocean dissolved the material before it could fossilize. It gives me something else to keep an eye at for when looking for Ordovician fossils.
Learn more at their web site: