Reply Response to Comment by Bence et al .

We welcome the opportunity to respond to the Comment of Bence et al. (2000) regarding the suitability of the new geochemical parameter we have introduced. Part of their comment, however, addresses issues either not directly related to our paper, or issues published elsewhere. The lengthy comment seems a disproportionate reaction to what was a paper of limited scope, simply introducing one new geochemical parameter, the refractory index (RI). The RI is a ratio of triaromatic steranes (T) to methyl chrysenes (C) (T/C); these compounds are ubiquitous in petroleum and are two of the most refractory components of the suite of polycyclic aromatic hydrocarbons (PAH) found in petroleum. The RI, therefore, was proposed as a source parameter potentially useful, in concert with other relevant geochemical parameters, in the correlation of oils over a wide range of environmental weathering conditions. The following paragraphs address some of the issues raised by Bence et al. (2000).