The northern fall of the Central Range, the largest unexplored area in New Guinea (Fig. 1), separates the swampy Sepik Plain in the north from the high dissected plateau forming the backbone of New Guinea to the south. The whole region is rugged and covered by tropical rain forest; it is almost uninhabited, and as there are few tracks, the long meandering southern tributaries of the Sepik River provide the only practicable access. The South Sepik region occupies a small segment of the fundamental break separating the stable Australian continental block from the oceanic crust to the north. This break, which is marked in the South Sepik region by the Lagaip Fault Zone, has had a profound effect on sedimentation in the region throughout the geological record: shelf-type sediments were laid down on the continental block, while geosynclinal sediments were being deposited to the north. The oldest rocks are Middle and Upper Triassic in age and include a widespread and distinctive volcanic unit called the Kana Volcanics. They are succeeded unconformably by a thick sequence of black pyritic shale (Lagaip Beds), which was laid down south of the Lagaip Fault Zone during the Jurassic and Cretaceous.

The Solomon Sea is a semi-enclosed oceanic basin bordered by technically active land masses: its morphology is dominated by an arcuate trough, the New Britain Trench, which bounds the basin on its northern side and is over 8000 metres deep. Density of soundings is sufficient to reveal a large scale left-lateral displacement near the western end of the New Britain Trench; this appears to be a continuation of the onshore Markham-Ramu Lineament. The same structure controls the position of the Markham submarine canyon, which is the major conduit feeding sediment to the ocean basin. No continental shelf is developed along the northern margin of the Huon Gulf owing to the strong and continuing uplift of the Huon Peninsula, which lies within the Northern New Guinea Arc structural province. South of Lae, however, a narrow continental shelf is present. Seismic reflection profiles reveal that this shelf is a geologically young constructional feature, composed in its upper levels of a coalescing series of deltaic deposits. In some areas these can be seen resting directly on non-sedimentary basement. Several submarine canyons cross the shelf and each is closely related to a large river onshore. The seismic records clearly show truncation of strata by the canyon walls: however, it is postulated that upgrowth of the shelf around the canyons, with occasional slumping along the rims, as well as axial downcutting by abrasive sediment flowage, have controlled the formation of the canyons. Their steep axial gradients, which average about 5° compared with the shelf surface which slopes seaward at only 1°, are taken to indicate that the canyons were initiated before the Pleistocene and have maintained their courses during the upward and outward growth of the deltaic deposits forming the present day continental shelf.

Conodonts of Ludlovian-Gedinnian age from the Yass Basin of New South Wales are described. The fauna consists of 61 species referable to 24 genera of which one, Coryssognathus, is new. Four conodont assemblage zones are recognized and correlated with classic Ludlovian-Gedinnian zones of Europe; two faunas, one of probable latialatus Zone age and the other of probable woschmidti Zone age, have also been recovered. Reworked Ludlovian conodonts from Devonian conglomerates at the top of the Yass succession are also described.

The Bowen Basin is a large triangular synclinal structure 350 miles long, occupying an area of about 20,000 square miles in eastern Queensland (Text-fig. 1). It is composed of Permian and Triassic sediments and volcanics resting unconformably on Upper Carboniferous or older rocks. To the southeast and southwest, the sediments dip under the Mesozoic strata of the Great Artesian Basin. Permian Polyzoa of the Bowen Basin belong to over 30 species and 16 genera of the Orders Cyclostomata, Trepostomata, and Cryptostomata. Four species, Fenestella bowenensis, F. springsurensis, Fenestella sp. nov., and Saffordotaxis multinodata, are regarded as being new. Twelve of the genera have been recorded previously from the Permian of Western Australia, and most of them are not known from the Permian of New South Wales and Tasmania. Thus a short-lived marine connexion with Western Australia is envisaged in the northern part of the continent.

In 1955 a programme of search for phosphate, to supplement the diminishing reserves of Ocean, Nauru, and Christmas Islands, was agreed upon by the Australian and New Zealand Governments. This Bulletin describes the search of islands of the South-West Pacific and Australian waters by the Bureau of Mineral Resources. Islands off the northern coast of Australia were investigated in 1957, the British Solomon Islands and islands off Papua and New Guinea in 1958, and Fiji, Tonga, and the Gilbert and Ellice Islands in 1959. The deposits of Bellona Island, B.S.I.P., are the only ones investigated by the survey that could be exploited and exported ; they contain about 500,000 tons of grade 30-3 percent P205 and 4,500,000 tons of grade 22-3 percent P205 . Other, smaller, deposits were found in: the Purdy Islands, Sae, and Manu (New Guinea); Tamana, Vaitupu, Abemama, Nukufetau, Tabiteuea , and Nui, in the Gilbert and Ellice Islands ; Vanua Vatu , Ogea Driki, and Tuvuca in Fiji ; and islands in the Ashmore Reef, Northern Territory . Many other islands contained traces of phosphate. The origin and uses of various types of phosphate deposit are reviewed.

Terebratuloids have a sporadic distribution in the Australian Permian rocks, but at some localities they are abundant. Two distinct provinces, an eastern and a western, are recognised. The eastern is dominated by the genera Gilledia SteWi and Fletcherithyris nom. novo pro Fletcherina Stehli; less abundant genera are Maorielasma Waterhouse, Marinurnula Waterhouse, Glossothyropsis Girty, Pseudodielasma Brill, and Jisuina Grabau. The last three genera are represented by a few specimens only, and are of little zoogeographical significance. The only other area in which similar faunas are known is New Zealand. The western province is dominated by Hoskingia gen. nov., but it also has representatives of Fletcherithyris, Gilledia, and Yochelsonia Stehli. The abundance of Hoskingia indicates possible relationships with the Tethyan and Uralian provinces, though the absence of the Notothyris group shows that there was no open migration from these areas. This distribution supports other evidence of a climatic difference between eastern and western Australia at this time. The group is of interest stratigraphically. The genera Maorielasma and Marinurnula, and the species of Gilledia, Fletcherithyris, and Yochelsonia, are all short-ranged. Many of the species are restricted to single basins. An attempt is made to provide a consistent terminology for the internal plates of terebratuloids, and a theoretical discussion of the homologies of these plates is given. It is shown that despite previous assertions to the contrary, punctation density can be a taxonomically useful feature in the group. In the systematic section the new Family Gillediidae and Subfamily Gillediinae are established, together with the new Genus Hoskingia of the Subfamily Dielasmatinae. In addition to the genera mentioned above, Beecheria Hall and Clarke is discussed in detail. The status of the long established species RhYllchonella' inversa de Koninck, Gilledia jervisensis (Etheridge), and G. cymbae/ormis (Morris) is considered, and it is shown that they cannot be adequately interpreted at the present time. The species Fletcherithyris amygdala (Dana), Hoskingia trigonopsis (Hosking), Hoskingia nobilis (Etheridge), and Yochelsonia thomasi Stehli, are redescribed. It is shown that Terebratula biundata McCoy is a synonym of F. amygdala (Dana). New species of Fletcherithyris, Hoskingia, Yoche/sonia, Gilledia, Maorielasma, and Marinurnula are described.

The aim of this Bulletin is to provide a reference volume outlining Australia's mineral resources. As far as possible, all known deposits of actual or potential economic importance, and deposits or fields from which production has been recorded in the past, are listed, and a brief description is given of the geology of the more important, including many which are no longer productive. The 55 chapters of this volume are in the form of summarized studies of individual minerals or groups of minerals. The treatment is necessarily brief but the reader who wishes to know more of any particular aspect of the subject will find, in the comprehensive list of references, a guide to detailed published descriptions. Production of the volume has been a co-operative effort. The work of the Bureau's team which assembled and wrote the chapters has been supplemented by data and comments received from the Mines Departments of the States and Territories. As a result this compilation represents a combined Commonwealth and State contribution to the propagation of information on the extent and variety of Australia's mineral resources. It is hoped that it will help to stimulate further mineral exploration in this country.

The object of this publication is to present statistical information which may be utilized in conjunction with the Australian mineral deposits described in Bulletin No. 72. The minerals and metals dealt with are arranged in alphabetical order. As far as possible the ore minerals are described under the name of the metal, but there are some exceptions to this rule. All tonnages are in long tons (2,240 lb.) unless otherwise stated. Statistics of Australian mine production are compiled mainly from data supplied by the State Departments of Mines, supplemented in places by other information made available to the Bureau of Mineral Resources. Such additional data are obtained from producers unless otherwise stated. The figures thus derived are more detailed than those of the Commonwealth Statistician's mine production statistics a series begun in 1952, and based also on information from the Mines Departments with some adjustment. Because of the difference in sources drawn upon and the degree of supplementary information employed, the two sets of figures do not agree in a few places. Import data shown represent full imports. The values of imports prior to 15th November, 1947 were recorded in British currency values f.o.b. and are so given in this Bulletin; as from that date, quoted values of all imports represent the f.o.b. values converted to Australian currency at the current rate of exchange on the day of import of the goods, and are as they appear in the Overseas Trade Bulletin. ? refers to £Australian, except where £ sterling is quoted in the same context when £A is used to avoid confusion. Australia changed to decimal currency on 14th February, 1966. Values expressed in £ (or£A) in this Bulletin should be multiplied by 2 to obtain values in $ (Australian). $1 = 1 0 / - (Aust.) [ = 8 / - (stg.) = $1*12 (U.S.) approx.].

Beach sand deposits along the Australian east coast (Gardner, 1951 a, b) have yielded a large part of the world supply of zircon and rutile since the year 1936. During 1953 the returns from the export of these minerals amounted to more than £2,000,000. In addition the black sands contain a small proportion of monazite, which is a source of cerium and of thorium, a fissionable element that may be used for the generation of atomic power. From a comparatively small beginning the mid-1930's the beach-sand industry grew rapidly during the war and early post-war years. Little was known of the distribution and reserves of the deposits; hence the Bureau of :Mineral Resources undertook a detailed investigation of the coastal area between Southport, Queensland, and Woody Head a little north of the mouth of the Clarence River, New South Wales. The primary object of the survey was to determine the reserves of monazite and therefore of thorium; the reserves of zircon, rutile, and ilmenite were also determined. In this report the source rocks of the sand and heavy minerals are considered in a brief outline of the physiography and general geology of the country between the coast and the main divide. The deposits are described and their origin and distribution discussed in connexion with late Pleistocene and recent changes, in sea level. The reserves and distribution of the heavy minerals arc broadly summarised, and more details of reserves and dimensions of deposits and overburden are given in descriptions of the individual areas.

One of the outstanding features of the Lower Miocene beds in Victoria is the presence of many larger foraminiferal species, many of the genera being restricted to this horizon, thereby being extremely valuable as zonal fossils, and affording excellent markers for the correlation of beds in different areas. The larger foraminifera have been found abundantly in the borings that have been put down for oil and water throughout the State. They also occur in several outcrops. The genera restricted to the Lower Miocene of Victoria include-Lepidocyclina, Cycloclypeus, Trillina, and Hofkerina. These are usually found associated with the more widely ranging large forms as Amphistegina, Operculina, Carpenteria, Gypsina, and Planorbulinella, there being definitely restricted species of the last two genera. These restricted species are found in friable polyzoal limestones and marls, and in hard limestones. In this Bulletin, no attempt is made at systematic descriptions of the foraminifera. It is more in the nature of an attempt to help the field geologist to locate himself in the Tertiary sections throughout Victoria.