W is for Wax
Leaves tend to cover themselves with wax to prevent water loss. This is convenient for us, because leaf waxes are often preserved in rocks. Analyses of these waxes can provide isotopic values for carbon, which can tell us about the plants present and general information about paleoenvironments. With specialized extractions, hydrogen isotopes from leaf waxes can provide important information about water availability in past environments.
Waxes are made in part of chains of carbon atoms called alkanes. The analysis of leaf waxes requires the separation of these alkanes into groups of the same length. Each same-length group will be analysed separately, as each different length of chain reflects plant water use and environmental aridity slightly differently.