Stable Isotopes Tracing of Origin of Ambers

This paper analyzed C, H and O isotopes of amber from Baltic, Dominica, Mexico, Burma, and copals with Stable Isotope Ratio Mass Spectrography (CRMS).Firstly, δ¹³C of ambers ranges between -19.38‰ and -25.76‰.δ¹³C of Burman ambers ranges between -19.38‰ and -22.90‰ with an average of -21.15‰.δ¹³C of Baltic ambers ranges between -22.76‰and -25.76‰ with an average of -24.35‰, and δ¹³C of Dominican ambers ranges between -23.57‰and -26.63‰ with an average of -24.99‰.Average C isotopes of ambers from those areas are different.Secondly, there is a good linear relation between δ¹³C of ambers and their formation ages.With the increase in geological ages of natural ambers, ¹³C of ambers increases regularly.It is thus suggested that maturity degree of ambers (from high to low) is the Burman amber, Baltic amber, Dominican and Maxican amber.Thirdly, δ¹³C of copals ranges between -26.82‰ and -29.94‰ with an average of -28.55‰.Based on data of experimental analyses, it is suggested that boundary value between amber and copal is -27.00‰ (+0.18, -3.00), which may provide an isotopic evidence to distinguish between amber and copal.Fourthly, δD of Burman ambers ranges between -195.90‰ and -244.40‰ with an average of -222.59‰.δD of Baltic ambers ranges between -235.90‰and -268.60‰ with an average of -253.46‰.δD of Dominican ambers ranges between -203.30‰ and -228.50‰ with an average of -219.05‰, and that of Mexican ambers is -218.90‰.Change inδD of ambers is closely related with latitude of amber formation.That is, with the increase of latitude, δD gradually decreases.Fifthly, two-dimensional space of ¹³C-¹⁸Oisotopes and D-¹⁸Oisotopes, and three-dimensional space ¹³C, D, ¹⁸Oisotopes of ambers vary from different producing areas.It is thus suggested that combinations of C, H and O isotopes of ambers can trace producing areas.