The systematic part of this paper is the continuation of my study (bpik, 1958) of the anatomy and concept of the genus Redlichia, presented on the basis of Redlichia forresti from the Negri Group of Western Australia, Redlichia idonea from the Yelvertoft Beds of Queensland, and some other, then unnamed, species. At that time (op. cit., p. 36) the taxonomy of the species was reserved for the future. This paper serves a double purpose-first, in presenting such speciestaxa as can be established from selected and properly preserved material, and second, in establishing a sequence of informal 'biostratigraphic operational units' in advance of a scale of Ordian zones. Such a scale of zones would be premature in view of the difference between the specific composition of Redlichia in Queensland and in the Northern Territory, and because of the incompleteness of data regarding the vertical distribution and specific taxonomy of Redlichia in many sites of the Territory, and the numerous undescribed other fossils of the Ordian of Australia. The fossils are kept in the Museum of the Bureau of Mineral Resources and the specimen numbers (CPC) refer to the Commonwealth Palaeontological (type) Collection.

Following the discovery of large phosphate deposits in the eastern part of the Georgina Basin in 1966 by Broken Hill South Limited, the Bureau of Mineral Resources embarked on a detailed stratigraphical and palaeontological study of the Cambrian sediments of the area in 1967. Particular attention was given to the phosphatic part of the section, but new information on the associated Cambrian units was also gained. In 1967, F. de Keyser, J. H. Shergold, C. G. Gatehouse, R. Thieme, and C. Murray (Geological Survey of Queensland) mapped the Burke River Outlier, and in 1968 de Keyser and Thieme mapped the Cambrian of the northeastern corner of the Barkly Tableland. In 1969 de Keyser and P. J. Cook completed the mapping of the known phosphogenic areas in Queensland when they mapped the eastern margin of the Georgina Basin in the Mount Isa/Urandangi area. Associated palaeontological, petrological, and geochemical studies were also carried out.

Lower Proterozoic sedimentary, metamorphic, and igneous rocks of the Pine Creek Geosyncline and Nimbuwah Complex form the basement rocks of the Bathurst Terrace. To the west of the Bathurst Terrace, along the eastern edge of the adjoining Bonaparte Gulf Basin, Phanerozoic sedimentation commenced in the Early Permian and led to the accumulation of a conformable sequence comprising the Kulshill, Hyland Bay, and Mount Goodwin Formations, and an unnamed Middle to Upper Triassic formation. It was not until the Late Jurassic that the sea transgressed onto the Bathurst Terrace to deposit the Petrel Formation, followed by the Bathurst Island Formation in the Cretaceous, and the Van Diemen Sandstone in the Early Tertiary. In the Late Cretaceous and Tertiary, chemical weathering produced an extensive cover of laterite. Mineral sands containing ilmenite, zircon, and rutile occur along the northern and western coasts of Bathurst and Melville Islands. Uneconomical deposits of bauxite crop out on the northern headlands of Cobourg Peninsula and Croker Island. In addition, uneconomical deposits of uranium, manganese, phosphate, limestone, clay, and hydrocarbons have been found in the area. Subartesian water is available on Bathurst and Melville Islands from aquifers in the Van Diemen Sandstone, and artesian water was discovered in the Marligur Member of the Bathurst Island Formation in the southern Cobourg Peninsula Sheet area.

19 maps on fold. leaves in v. 2. pt. A. Notes on the geology of the northern part of the Eromanga Basin, Queensland. -- pt. B. Notes on the geology of the central part of the Eromanga Basin, Queensland. -- pt. C. Notes on the geology of the northwestern part of the Eromanga Basin, Northern Territory and Queensland.

The Arrinthrunga Formation (Upper Cambrian) in the Georgina Basin, central Australia, is a complex carbonate and mixed carbonate-siliciclastic sequence deposited in an extensive and intermittently emergent epeiric sea. It accumulated on a low-relief substratum in very shallow water with restricted tidal movements; these factors and a warm arid climate contributed to high salinities and the local precipitation of evaporites. Filamentous algae proliferated in the warm hypersaline shallow waters, in which grazing organisms were virtually absent, and exerted a major control on the type and distribution of carbonate lithologies. At the close of the Middle Cambrian a peloid shoal or barrier bar prograded across a broad region of shallow-marine tidal carbonates, bordered in the west by intermittently emergent algal flats. A hypersaline lagoon developed in the lee of the shoal, and a thick sequence of algal-derived peloid lime-muds was deposited. Shoaling sedimentation and intermittent emergence favoured the establishment of gypsiferous algal mats in the northwest, and, with increasing emergence, laminated algal mats colonised much of the area. A transgression of the sea then flushed the stagnant waters, and a reticulate maze of algal bioherms and interbiohermal peloid-ooid sands was established across the whole of the depositional area. Under the influence of shoaling sedimentation and a stable sea level, nearshore environments migrated laterally, and quartz-ooid shoals, intermittently emergent algal mats, and terrigenous sands prograded across the western and central portion of the sea. The progressive shallowing led to local emergence, reduced circulation, and stagnation, so that sections of the sea became isolated and halite evaporite pans were formed. A second transgression of the sea again favoured the widespread growth of algal bioherms, and prograding ooid shoals then spread out across all but the eastern portion of the depositional area. Sedimentation ended as the sea regressed, and a karst erosion surface formed on the emergent landmass.

Idamean trilobite assemblages are described in this Bulletin from localities in the central portion of the Burke River Structural Belt, on the southern part of the Duchess 1: 250 000 Geological Series Sheet (Carter & bpik, 1963) (Fig. 1). Idamean trilobites have been collected in this area several times since their first published descriptions by bpik in 1963. During 1967 C. E. Murray (Geological Survey of Queensland), then attached to the Bureau of Mineral Resources Northwest Queensland Phosphate Group, collected from localities along the eastern margin of the Structural Belt during routine mapping between Moonlight Bore and Mistake Bore (Fig. 1); and F. de Keyser obtained trilobites from the western side of the Structural Belt southeast of Pilgrim Well. In 1969, J. H. Shergold collected sequences at Mount Murray during an investigation of the trilobite assemblages of the nearby Chatsworth Limestone, and again in 1974 when the Mount Murray sections were surveyed as part of an appraisal of the relation between the Pomegranate and Chatsworth Limestones. All new material described in this Bulletin is deposited in the Commonwealth Palaeontological Collection (CPC), Bureau of Mineral Resources, Canberra. Older material is refigured from Whitehouse's collections, which is housed in the Fossil Collections, Department of Geology, University of Queensland, St Lucia (UQF).

The Scott Plateau and the adjacent Rowley Terrace occupy an area of about 160 000 km2 in water depths ranging from 300 to 3500 m off Australia's Northwest Shelf. The Scott Plateau forms a subsided western margin to the Browse Basin. For much of the time between the Permian and Late Jurassic, the plateau was probably higher than the adjoining basins, shedding sediment into the Browse Basin to the east and the Rowley Sub-basin to the south. Since break-up of the continental margin in the Callovian, the plateau has gradually subsided to its present depth of 1000-3500 m, and is now covered by a blanket of Upper Cretaceous and Cainozoic sediments, mainly carbonates, averaging 1 km in thickness. Seismic, magnetic, and gravity data indicate that, over most of the plateau, basement of possible Kimberley Block equivalents is probably no more than 2 to 4 km below the seabed. The southern part of the Scott Plateau and the Rowley Terrace are underlain by the Rowley Sub-basin. The Rowley Sub-basin is a pull-apart basin that trends east-northeast and contains largely Mesozoic sediments; it differs from other pull-apart basins of the Northwest Shelf because it is only mildly deformed. The basin probably contains at least 6 km of prebreak- up Mesozoic and Palaeozoic rocks, overlain by a post-break-up sequence that has an average thickness of 1.5 to 2 km, thinning to zero at the top of the continental slope. The hydrocarbon potential of the Scott Plateau appears to be only fair. The highest potential appears to be in the Scott Plateau Saddle, which may have suitable source, reservoir, and cap rocks, and structural and stratigraphic traps. Over much of the plateau, the potential hydrocarbon-bearing rocks are probably no younger than Palaeozoic, and are unlikely to be more than 2 to 4 km thick; any hydrocarbons generated in them would probably have been lost during the prolonged emergence and erosion that preceded break-up. The hydrocarbon potential of the Rowley Sub-basin cannot be regarded as high. The thickness of the sediments in the sub-basin is adequate for hydrocarbons to be generated, but drilling at East Mermaid No. 1 indicated a possible lack of suitable source rocks. In addition, the lack of structure in all but the deeper parts of the sub-basin must downgrade prospects.

This Bulletin presents the results of systematic geological mapping in north Queensland by joint field parties of the Bureau of Mineral Resources and the Geological Survey of Queensland, during the period 1958 to 1963. The area investigated is more than 36,000 square miles, and extends from Princess Charlotte Bay in the north to the township of Ingham in the south, and from 142°30'E. to the shores of the South Pacific Ocean. It is the site of a Palaeozoic geosyncline the Hodgkinson Basin and includes part of the western Precambrian borderland, which is separated from the geosyncline by the Palmerville Fault, a large fundamental structure.

Beyrichicopids and kirkbyocopes are represented in the Early Carboniferous benthic ostracod fauna of the Bonaparte Basin by at least 29 species referable to 18 genera (including two that are probably new, but unnamed). The described number of species are distributed among the ostracod families. Of the species described, eight are new (Libumella bonapartensis, Welleriella atypha, Malnina spinosa, Coryellina excaudata, C.robertsi, Selebratina serotina, Tetrarhabdus dictyon, and Scrobicula inaequalis), eight are closely related to, if not conspecific with, established taxa [Pseudoleperditia cf. venulosa, Coryellina cesarensis, Kirkbya aff. lessnikovae, K. aff. quadrata, Amphissites aff. centronotus, A. umbonatus, Kirkbyella (Berdanella) quadrata, and Scrobicula aff. inaequalis), and 13 are placed in open nomenclature, most of which are comparable with previously described taxa. The morphological similarities of the extinct Kirkbyacea and the extant Punciacea are discussed, and possible homoemorphic resemblances between them are considered. Detailed SEM examination of the reticulation pattern of the kirkbyacean species Amphissites sp.B revealed the results of epidermal cell-division during the ecdysis between the A-I stage and the presumed adult stage. Mitosis of the epidermal cells not only increases the valve surface area, but also initiates carinae by the fusion of adjacent muri of twin fossae. An interim biostratigraphic scheme for the Early Carboniferous sequence of the Bonaparte Basin consists of a succession of eight ostracod assemblages that are based on the first appearance (in ascending order) of the following species: Welleriella atypha, Coryellina robertsi, Shivaella cf. armstrongiana, Coryellina cesarensis,. Malnina spinosa sp. nov., Selebratina serotina, Scrobicula inaequalis and A mphissites sp.B. The scale of assemblages is controlled by conodont and foraminiferal zonations, and is calibrated against the Dinantian time-scale. So far, the atypha, robertsi and armstrongiana Assemblages have been recognised in the Early Carboniferous (Tournaisian) sequence of the Canning Basin. The major affinities of the Early Carboniferous beyrichicopids and kirkbyocopes from the Bonaparte Basin are with cognate species from Western Europe (Belgium, northern England), the Russian Platform, Kazakhstan, and Tibet. North American affinities are of minor significance. In general terms, the entire Early Carboniferous ostracod fauna from the carbonate shelf sediments of the Bonaparte Basin belongs to the Bairdiacea-Paraparchitacea ecozone, suggesting warm climatic conditions. The Tournaisian (Burt Range Formation; Septimus Limestone) faunas may include ecologically mixed assemblages, i.e., marine nearshore and shallow offshore, but the palaeoecological studies needed to test this model must await the description of the total Early Carboniferous ostracod fauna. The Visean (Utting Calcarenite) Kirkbyacea are as frequent (in species abundance) as the Paraparchitacea, both superfamilies ranking second to the Bairdiacea; a proportion indicative of open-marine shallow offshore conditions.

The Canberra 1: 100 000 Geological Sheet covers about 2500 km2 of hilly, upland terrain in the Australian Capital Territory and southeastern New South Wales. The bedrock comprises Ordovician to Silurian sediments and acid volcanics which have been invaded by several generations of Silur<rDevonian acid and basic intrusions. Crustal evolution was from an oceanic environment characterised by turbidites in the Ordovician to a shallow-marine shelf and emerging terrestrial conditions in the Silurian represented by sediments and widespread pyroclastic flows. The sequence has been folded, faulted, and weakly metamorphosed by a series of mid Palaeozoic earth movements which have given a strong meridional trend to the geological structure. The region has been stable since the Carboniferous, apart from minor fault movements and intracratonic sedimentation associated with Cainozoic epeirogenic uplift.