A thick superficial cover of weathered dacitic ash that mantles the flatter ridge crests on hills and mountains for up to 30 miles (48 km.) from Mount Lamington was derived from this strato‐volcano and thins with distance from it, being about 40 ft (12m.) thick 20 miles (32 km.) away. Its mineralogy is similar to that of the oldest lavas exposed in Mount Lamington crater and to the ash and pumice erupted in 1951. Size distributions of the ash show very good sorting. Inman's coefficientσø,0–8 to 1–2, and median diameters have a small range, 0.25±0.10 mm. The sorting, mineralogy, and accordance of the layers with the present topography, indicate an ash‐fall origin.