A reconnaisance soil gas detection survey for light alkanes was conducted within PEL 32 during the week of 5-12 April 1988, to determine the geochemical expression of the Katnook prospect gas discovery area and other seismically-defined prospects and leads lying a little distance to the west. 287 gas samples taken from 3 main areas were analysed, with the most intense coverage being obtained at a 500 metre spacing along Katnook area seismic lines also being shot for the 1988 Penola detailed Seismic Survey. A few anomalies of interest were then sampled more closely at 200 to 250 metre intervals to better check their character. The area around the Katnook 1 gas discovery well was found to be characterised by anomalous samples confirming the presence of hydrocarbons at depth. Other indications from this part of the survey point to an additional, similar character accumulation of hydrocarbons occurring to the southeast of Katnook 1, besides a general scattering of lesser anomalies that may correspond to near-surface faults transecting the prospect. Results from the portions of the soil gas survey run to the west of the Penola seismic grid indicate that the mapped prospects and leads in these areas are not as geochemically significant as the Katnook prospect.