Now, thanks to a new geochemical method developed by Temple University graduate student Doreena Patrick, scientists have a new tool to aid them in placing loose fossils back into the earths strata or determining the fossils legitimacy.
Paleontologists need to know where a fossil goes in the strata in order to understand the grand picture of evolution, as well as the evolution of that creature, says Patrick, who conducted her research under Temple geology faculty members David Grandstaff and Dennis Terry. What I wanted to do, ultimately, was be able to place a fossil back into its correct strata, which is called fossil provenience.
By analyzing a fossil bone for rare earth elements (REE), which are located at the bottom of the periodic table, Patrick is able to identify a unique signature for that bone and match it with other fossil material from the same strata.
During the fossilization process, the calcium in the bone is replaced by trace elements, some of which are rare earth elements, she adds. The REEs that are within the bone can tell where in the earths strata that bone was originally located.
Patrick, who earned her bachelors degree in chemistry from Temple in 1984, found that the trace elements are taken in preferentially, depending upon where in the strata the bone is sitting. The bone will pick up the rare earth elements in direct proportion to the amount of rare earth elements in that particular strata, earning it a unique rare earth signature.
A resident of North Wales, PA, Patrick says the studies have revealed that it takes, theoretically, about 10,000 years for a fossil bone to pick up its signature.