New palynology has confirmed the pattern of algal maxima associated with high gamma ray well log response within the Laira Shale, and indicates that there are 3 major and regionally correlatable 'hot shale' horizons, plus a less obvious one, within this unit in the Penola Trough. Spiny acritarchs are also intermittently associated with these horizons, suggesting slight brackish influence. Overall, these horizons suggest highstand intervals, producing widespread lake development in which algae flourished, and even intermittent saline influence from a nearby marine gulf. At the base of the Laira Shale another hot interval occurs, but shows no algal association. Correlation of drill cuttings samples, using the F. wonthaggiensis subzones in conjunction with algal maxima and their associated gamma responses, produces a set of Laira Shale members designated A to E of at least local correlative value. In the Kalangadoo 1 well, study of additional cuttings suggests a thicker Laira Shale intersection than previously noted.