This folio is the culmination of an extensive seismic mapping and interpretation of the Cooper and Eromanga Basins, South Australia that commenced in 1995. It follows earlier mapping of the C Horizon (Top Cadna-owie Formation) that commenced in 1991. Whilst this folio is restricted to the immediate area of PELs 5 and 6 which encompasses the entire South Australian portion of Cooper Basin, mapping extended to the Pedirka and Simpson Basins and the Eromanga Basin. Three key horizons; C, P (Top Permian) and Z (Basement) are mapped in both time and depth at 20m contours using open file company seismic data. Additional depth structure maps have been constructed using well data to phantom between these 3 horizons. Volume 1 of the Cooper Basin Folio provides industry with a snapshot of key seismic depth structure maps, formation isopachs and structural elements (supplemented by infrastructure, licence areas, seismic coverage, land systems and uses) to assist them in developing their exploration strategies leading up to relinquishment of PELs 5 and 6 by Santos Ltd in February 1999. Volume 2 concentrates on geological datasets including lithofacies mapping, maturity maps of key source intervals, depths to oil and gas windows and gas wetness maps.