Biomarker (petroleum)

Biomarkers are any of a suite of complex organic compounds composed of carbon, hydrogen and other elements such as oxygen, nitrogen and sulfur, which are found in crude oils, bitumens, petroleum source rock and eventually show simplification in molecular structure from the parent organic molecules found in all living organisms. Essentially, they are complex carbon-based molecules derived from formerly living organisms. Biomarker compounds are typically analyzed using gas chromatography and mass spectrometry. Some examples of biomarkers found in petroleum are pristane, phytane, steranes, triterpanes and porphyrin. Geologists and Geochemists use biomarkers traces found in crude oils and their related source rock to unravel the stratigraphic origin and migration pathways of presently existing petroleum deposits.