Publication Name: CENTRAL AUSTRALIAN BASINS WORKSHOP 1993 (CABS 1)
Authors: Roger E. Summons, Dennis Taylor, Christopher J. Boreham
Date Published: September 1993
Number of Pages: 1
Abstract:
There is a perception that maturity estimates based on geochemical investigations need to be assessed against the "yardstick' of the more conventional vitrinite reflectance. However, in Proterozoic and Early Palaeozoic sediments, which pre-date the evolution of land plants (precursors to vitrinite), we will show that the geochemical tools developed for younger source rocks can be successfully applied. In particular, isomer distributions in aromatic hydrocarbons (e.g. the methylphenanthrene index, MPI), when combined with data from the pyrolysis of whole and solvent-extracted rocks, is a useful tool for definition of the oil window in petroleum source rocks, oil maturity and detection of migrated oil. Furthermore, the character of the precursor organisms during this early evolutionary time bestowed unique chemical signatures on the kerogen and free hydrocarbons. In response, some classical geochemical tools for source and maturity evaluation are either inappropriate or require slight adjustments.