摘要
REE （rare earth element） analysis of bioapatite has recently been used to determine fossil provenience, taphonomy, stratigraphic correlation and paleoenvironmental conditions. This research has determined that REE signatures are independent of diet, species, phylogeny and osteological material. Therefore, REE signatures are solely dependent on the depositional environment. Timing of emplacement could limit the resolution of REE analysis so it is vital to understand the length of time for REE signatures incorporation into bioapatite. A fossiliferous Pleistocene sites in Fossil Lake, Oregon has the potential to address this variable. A fossilized rabbit was found in its burrow and was contained in the uppermost unit that also is host to a semi-articulated fossilized salmon. The rabbit burrowed into this unit after the lake was subaerially exposed and is not contemporaneous with the salmon. REE signatures were found to be equivalent. The timing of emplacement of the REE signatures has to be less than the difference between the age of the salmon and the rabbit. Since the uppermost units of Fossil Lake are younger than 45,000 BP the remains can be dated with carbon-14. Therefore, this research aids in further quantifying the timing of emplacement of REE signature in bioapatite.
