This report is based on field work at Jervis Bay and in the surrounding area during the period 4th to 30th June, 1952. The purpose of the investigation was primarily economic, though no further attention was given to the deposit of firebrick clay previously described (Smith et al., 1948). Outcrops in the Commonwealth Territory at Jervis Bay consist almost entirely of sandstone of Permian age. The name Jervis Bay Sandstone is proposed for these rocks, which have been found to underlie the Wandrawandian Siltstone, and are tentatively correlated with the Conjola beds - all units of the Shoalhaven Group, which includes part of the former Upper Marine Series. Marine fossils having affinity with those found in the former Upper Marine Series have been found in the Jervis Bay rocks. The sandstones have been invaded in a few places by basic intrusive rocks, probably during the Tertiary Period. The only materials of economic significance found in the Territory are firebrick clay, and ferruginous gravel useful for surfacing roads. Additional supplies of the ferruginous gravel may occur in the areas delineated on the map as suitable for further prospecting.