CHEMOMETRIC ANALYSIS OF PYROLYSATE COMPOSITIONS - A MODEL FOR PREDICTING THE ORGANIC-MATTER TYPE OF SOURCE ROCKS USING PYROLYSIS-GAS CHROMATOGRAPHY

The application of chemometrics to pyrolysis-gas chromatography (Py-GC) data has resulted in a model that provides an objective means of predicting the original hydrogen index (HI0) of a source rock from a single Py-GC measurement. Twenty-five organic-rich rocks, representing four different organic matter types (OMTs) at various levels of maturity have been analyzed using Py-GC. Principal components (chemometric) analysis (PCA) of aliphatic, aromatic, phenolic, and sulfur-containing compounds in the pyrolysates indicate a small subset of pyrolysate components (thirty-seven compounds) contain the diagnostic information needed for sample classification. Our results illustrate the usefulness of chemometrics for determining relationships in large, complex datasets. Furthermore, our model provides the objective prediction of key geochemical/geological parameters from pyrolysate compositions.