Australian rock phosphate production has never been significant, and over the last two years steps have been taken to remedy the situation. This has and will involve time-consuming geological review work, leading to reconnaissance mapping, detailed investigation, drilling, assaying, etc. The Cambrian deposits of Duchess, near Cloncurry, Queensland, a major discovery announced late in 1966, are the first rewards of this renewed exploration; they are, however, unfortunately located geographically and transportation costs will be considerable. In 1965, British Petroleum became interested in another approach to the problem, by examining the possibilities for the development of marine phosphorite off Australia. It was felt that an inexpensive marine reconnaissance might lead more quickly to the establishment of an Australian phosphate industry, assuming always that the commodity was located close to markets and not in waters of excessive depth. Mineral exploration concessions over four areas of offshore Western and South Australia, including SML 107 in SA, were granted to BP Minerals Australia Pty Ltd in March 1966. It was appreciated that over these vast areas of unsurveyed continental shelf and slope certain parameters believed important for phosphorite accumulation could be absent. Bathymetric information, and consequently, knowledge of bottom topography, was meagre, and records of current directions contradictory. Sedimentation rates, however, were apparently favourably low. Between 14/11/66 and 12/3/67, Australian Hydrographic Services Ltd using the H/V Ataluma under contract to BP surveyed the concession areas by profiling and sampling the ocean bottom sediments at roughly 5 mile intervals along an uneven grid system. Within South Australian waters, approximately 37 days were spent investigating 8,790 square miles of the continental margin south of Kangaroo Island, and about another week was spent investigating 3,050 square miles of the SA portion of the Great Australian Bight. The survey found limited amounts of phosphatic sediment, but no phosphate nodules, in all four concession areas. No economic deposits of modern phosphorite or phosphatic sands were revealed, and cannot now be expected to occur, in any of these areas. According to the depth of the water and the nature of the deposit, upwards of 25% P2O5 by weight would be required to make exploitation feasible. The results of sample analyses strongly suggest that there is little likelihood of finding a modern phosphorite accumulation in Australian coastal waters between Exmouth, WA and Kangaroo Island, SA. It seems that this part of the Australian continental margin is too remote from regions of oceanic upwelling of cool waters rich in phosphate ions. This is supported by the low phosphate ion content of Western and South Australian seawater given in the literature. Furthermore, it is in fact not definitely known whether active marine phosphorite deposition is actually occuring today anywhere in the world. Nodules of offshore Californian phosphorite contain Miocene to Pleistocene fossils, and those of New Zealand's Chatham Rise have been dated as Miocene or younger. Other regions have yielded nodules of more ancient origin from the continental slope. Older deposits of phosphate rock may eventually be found off Western and South Australia, but these would have to be of the remanie type and not buried under a carbonate cover to be of more than academic interest.