The 30th International Geological Congress was held in Beijing, China in August 1997. Leading scientists convened to present their findings and views to the international geological research community. Volume 18a of 26 focuses on the geology of fossil fuels, specifically oil and gas. All articles in the proceedings have been refereed and keynote papers have been included in Volume 1. These proceedings aim to present a view of contemporary geology and should be of interest to researchers in the geological sciences.