Bulk carbon, oxygen, and hydrogen stable isotope composition of recent resins from amber-producing Hymenaea

摘要

Resins of Hymenaea, an angiosperm tree genus known to be a copious resin producer and a major source of amber since the Oligo-Miocene, were collected from a wide range of tropical environments from Latin America and Africa, and analyzed for their carbon, hydrogen, and oxygen stable isotope composition. The average value for δ~(13)C in the resins was found to be -27.0+-1.3 per thousand, which is very similar to the values reported for resins in other studies. δ~(18)O values for the Hymenaea resins averaged +11.2+-1.6 per thousand, or about 20 per thousand more depleted than normal plant cellulose. SD values of the resins ranged from -196 to -319 per thousand, with an average of -243+-30 per thousand. Rough estimates suggest a fractionation of -200 to -210 per thousand between the resins and the environmental water. This value is similar to the -200 per thousand value observed for the fractionation between other plant lipids and environmental water. The present study suggests that the stable isotope composition of fossil resins (amber) has the potential to provide information on ancient environmental waters.