Taphonomy of fossilized resins: determining the biostratinomy of amber

Abstract

Comparing the maturity of fossilized resins with that of their enclosing bedrock can provide information on the maturity, relative age and biostratinomy of amber and copal. A method to determine this is presented here with examples of amber and copal from the Dominican Republic. Maturity of the bedrock was determined by vitrinite reflection and that of the fossilized resin by FTIR analysis. Vitrinite oxidation values showed maturity states corresponding to lignite and sub-bituminous coal ranks. While the samples from some mines demonstrated that the maturities of the rock and fossilized resin were syngenetic, other samples indicated that recycling of the amber may have occurred. Darkening of the amber (from yellow to red) was correlated with increased oxidation / weathering. This method can be a useful tool for understanding the biostratinomy of fossilized resins.