Broad Sound is situated at the confluence of four large estuaries. Freshwater inflow is restricted to the summer months. The Sound and its attendant estuaries are characterized by shallow water, a large tidal range (10 m), and strong tidal currents. In the shallow marine environment (the most seaward) pre- Holocene relict calcareous gravels are common. Calcareous sands, commonly occurring as sand ridges capped by megaripples, predominate in the open intertidal environment. Muds are most abundant in the mangrove swamp, mangrove channel, and supratidal flat environments, the muds become less calcareous and more saline in a landward direction. Textural studies revealed that grainsize parameters can be used to divide the sediments into environmentally significant groups; they also indicated that most of the sediments are brought into the estuaries during times of summer floods, and redistributed by tidal currents during the remainder of the year. The petrology and mineralogy of the sediments are consistent with some relative seaward movement of terrigenous sediment and landward movement of calcareous sediment. The relict nature of some of the sediments is revealed by their mineralogy, in particular their lack of less stable carbonates and heavy minerals. There is a seaward trend of increasing maturity in both the heavy-mineral and light-mineral assemblages. Drilling and radiocarbon dating have shown that most of the sediments are of late Holocene age. It appears from the Broad Sound evidence that sea level stabilized about 6000 years ago. Since that time there has been a marked seaward progradation of the shoreline producing a 'fining upward' regressive sequence. Regression appears to have been more rapid on the east side of the Sound, possibly a result of some late Holocene uplift. The Broad Sound study is valuable because it provides not only a regressive model for environmental interpretation in ancient sediments, but also a yardstick against which environmental changes in tropical estuaries can be measured.

A correlation chart for the Triassic System in Australia is presented. The base of the System in Australia is taken as the earliest occurrence of the Lunatisporites pellucidus Assemblage Zone in a section of the Rewan Formation in the Bowen Basin, Queensland, and the base of the Jurassic System as the occurrence of Ceratosporites helidonensis with ClassopoWs and Retitriletes austroclavatitides in the Upper Woogaroo Subgroup in a section near Ipswich in the Moreton Basin. Correlations within Australia are based predominantly on microfioral evidence with supporting evidence from fossil vertebrates and, to a minor degree, on macrofiora. Correlation of Australian units with those in other continents depends on ammonites, bivalves, conodonts, vertebrates, and microfiora in Lower Triassic units; and on vertebrates and microfiora in higher units. A cross-indexed bibliography on the Triassic System in Australia covering 21 years to the end of 1973 is also provided.

Irene Crespin, O.B.E., B.A., D.Sc., has both pioneered her field of study and become an internationally accepted specialist-a goal of many scientists. Therefore it is most appropriate to honour such a distinguished Australian micropalaeontologist with a commemorative volume of special papers in this, her eighty-first year; and it is a pleasure and honour for me to be associated with this volume, which was initiated and organized by her colleagues and foraminiferal specialists Dr D. J. Belford, who has carried on her work in the Bureau, and Dr Viera Scheibnerova.

The pocket in this Bulletin contains five Australia-wide correlation charts and location maps in microform (together with microform of the Bulletin text). The charts summarize the stratigraphy of the major Australian basins that belong to two categories in the Tectonic Map Map of Australia and New Guinea (1971) Trans- Australian Platform Cover and Central Australian Platform Cover. Several basins belonging to Transitional Domains have also been included because one of them (Adavale Basin) contains hydrocarbons. The platform cover in Australia that is Adelaidean to Recent in age can be studied in five major time-rock groupings, each of which forms the basis of one of the charts. These groupings are clearly similar to the 'megasequences' described by J. W. Porter and R. G. McRossan for the Phanerozoic of Canada and which appear to have worldwide significance and seem to conform to major events preceding and following the breakup of Pangaea (Basin consanguinity in petroleum resource estimation. In Haun, J. D. (Ed.), Studies in Geology No. I-Methods of estimating the volume of undiscovered oil and gas resources. Amer. Ass. petrol. Geol., Tulsa, 1975). An attempt has been made to show the lithology, maximum thickness and environment of deposition of the various beds listed. Estimates of hydrocarbon reserves are as quoted in BMR Petroleum Newsletter No. 62 (1975). A wide range of published stratigraphic correlations and interpretations has been used in the compilation. No rigid interpretation of age or equivalence of strata should necessarily be presumed by the layout of the data in the charts. Brief notes on the major time-rock groupings follow, together with selected bibliographies.

On the recommendation of the Australian Upper Mantle Committee, the Bureau of Mineral Resources carried out a seismic survey across the Precambrian shield in southwestern Australia between June and December 1969. Deep crustal reflection and refraction information was obtained from explosions set off in five areas along the Geotraverse, a line extending from Perth through Coolgardie in the east to Point Culver in the southeast. The results have been combined with those from gravity surveys and from other seismic refraction surveys in southwestern Australia to obtain an integrated interpretation of the structure and composition of the crust and upper mantle. The reflection surveys included continuous profiling, offset recording, expanded spread velocity profiling and common-depth-point profiling along short traverses in the five areas. The quality of the analogue-processed sections was generally poor, and the probable reflection events, of very low relative amplitude, could be picked only from repetition of events over a few traces. Digital processing of the data effectively increased the relative amplitudes of the events and generally improved their continuity, but it also raised the level of some noise events and produced a smearing of all events over a greater number of traces than before processing. The lack of any distinctive reflection character and definitive vertical velocity information in the poor-quality data makes it impossible to correlate probable reflection events from one area to another along the Geotraverse. The reflection information was, however, useful in providing support to the interpretation of the refraction data between Perth and the Jubilee Mine about 60 km northeast of Kalgoorlie. Refractions from the large reflection shots were also recorded at temporary and permanent seismograph stations between Perth and the Jubilee Mine, and between Perth and Albany. The quality of the refraction data recorded during the Geotraverse project, and of those recorded earlier but used in the analysis here, suffers from irregular spacing of the recording stations, insufficient lengths of some traverses, and irregular clusters of data points near the critical recording distances for the various layers. The reliability of the refraction analysis depends largely on the correlation of second and later arrivals. However, the generalized structure interpreted from the refraction data is considered to be the most probable one as it is consistent with the interpretation of reflection and gravity results. The analysis of the seismic data indicates that the crust is of normal continental type in the east but changes towards the Perth Basin in the west. Near Kalgoorlie it consists of two layers with velocities of 6.12 and 6.66 km/s and is 34 km thick, whereas near Perth, close to the continental margin, it is 44 km thick and includes an extra basal layer of velocity 7.42 km/s, which thins out towards the east and southeast. The upper two crustal layers near Perth, on the other hand, thicken to the east and southeast. In the Perth Basin, about 7.5 km of sediments overlies a block of the crust which has been thrown down to the west along the Darling Fault. Southeast of Coolgardie, the high-velocity basal layer is shown to be thin and the southeastern part of the crustal block has been upthrust to the northwest along the Fraser Fault. The measured velocity of the upper mantle underneath the abnormal crust is 8.25 km/s. The seismically determined structure is consistent with a crust in or close to isostatic equilibrium, and with the observed gravity anomaly field in southwestern Australia for two possible density models of the crust and upper mantle. One of the density models is also consistent with the hypothesis that the highvelocity basal layer in the crust is garnet-granulite overlying eclogitic mantle.

In the Mary Kathleen 1:100 000 Sheet area, three major rock units are recognized a Lower Proterozoic? to Carpentarian central crystalline basement block (Kalkadoon- Leichhardt block), which is flanked by the predominantly Carpentarian meta sedimentary eastern and western successions.

A fauna containing both larger and planktic smaller foraminifera has been found in two samples from New Ireland, Papua New Guinea. The planktic foraminifera indicate an age within the N.II-N.12 zonal interval; a new species, Globigerina edita, is proposed. The larger foraminifera consist mainly of lepidocyclinids, referred to the species Lepidocyclina (N.) howchini howchini Chapman & Crespin. Biometrical analysis of the lepidocyclinids has been made using two parameters: the degree of curvature and parameter F (the form number). The degree of curvature does not seem to be a reliable criterion for inter-regional correlation; more data are required for parameter F.

Part I. deals with Devonian coral faunas from the West Kimberleys, the East Kimberleys, and the Carnarvon Basin of Western Australia. Of the 30 species described and illustrated from the West Kimberley's, 22 are from the Pilbara Limestone, and of these fifteen are from the main (lower) part of the Limestone of Givetian age, but there are five from the Atrypa beds of Teichert which the Bureau of Mineral Resources equates with the upper part of the Pillara Limestone and which may be late Givetian or possibly Frasnian; one Disphyllurn occurs in Atrypa beds referred by Teichert to Oberdevonstufe (Frasnian). This Pillara Limestone fauna (lower and upper) is dominated by Disphyllum with Hexagonaria, Thamnopora, and Alveolites also important. The overlying Mount Pierre Group, of Frasnian (Oberdevonstufe I) and early Famennian (ll and III) age, and the Bugle Gap Limestone (IV), have a strikingly different fauna mostly of small slender solitary corals. A new genus of Rugosa, Catactotoechus, type, species C. irregularis sp. nov., is described and figured. The East Kimberley corals are the Upper Devonian Palaeosmlia contexta sp. novo and Syringopora patula Hinde. From the Carnarvon Basin only four species are known, all from the Gneudna Formation; the genera to which they belong are those dominant and characteristic in the Pillara Limestone of the West Kimberleys, and in upper Givetian and early Frasnian faunas elsewhere, so that the Gneudna Formation Is probably of this age; the lack of identical species between the Carnanon and Kimberley Basins may be due to differences of province rather than time. The Western Australian Givetian coral faunas contain no species in common with those of eastern Australia, and many of the genera characteristic in eastern Australia, such as Endophyllum,, Sanidophyllum, and Heliolitcs, are absent in Western Australia. Part II deals with fragmentary coral material from the Silurian limestone, near Kiandra, southern New South Wales, including Halysites brevicatenatus sp. nov.; only two species are identified with previously described Australian forms, but the age indicated is probably Wenlockian, possibly Ludlovian.

At the request of the Geological Survey of Western Australia, the Bureau of Mineral Resources, Geology and Geophysics provided geophysical staff and equipment to assist in the search for underground water supplies in certain areas of Western Australia where additional supplies are required for further development of the farming 'industry. The main objects of the survey were to test several -types of resistivity equipment and to determine their limitations and optimum working conditions, to estimate the accuracy of depth determinations to formation discontinuities, to determine, the nature of the discontinuities, and to estimate the degree of salinity of the ground water. Results show that in 75 per cent of the measurements made, errors in depth determinations were within ± 20 per cent. Although limited control data were available, it was often possible to recognize limestones, cementation zones in limestone, sands and ground-water levels, and in granite areas, the transition from weathered to fresh granite was readily recognized. Where conditions were favourable, a satisfactory correlation was obtained between resistivity values and the salt content of solutions in a formation, provided the porosity of the formation was known. Although the main object of the survey was not, the finding of new underground water supplies, this WJ.S one of the aims in the Cue area, and a location was found where conditions for a large supply of good-quality water appeared to be favourable. The resistivity meter which was used in the tests was developed by the Bureau of Mineral Resources, and operated very satisfactorily. The Megger earth tester was reliable up to electrode spacings of 100 feet. The value of future test surveys for underground water would be greatly enhanced if more comprehensive bore information were available for correlation and combination with geophysical and geological observations. Such information should include the porosity and permeability of formations, screen analyses of samples, and salt content and resistivity of bore water.

A collection of Palaeontological Paers, 1967.