The Australian Calibration Line (ACL) , with a total gravity interval of 3 Gal, was established during 1970 between Laiagam in Papua New Guinea and Hobart in Tasmania. During 1973 the Australian Bureau of Mineral Resources and the USSR Geodesy and Cartography Survey made joint observations along the full length of the ACL. Measurements made with eight Soviet GAG-2 gravity meters established a gravity scale for Australia to an accuracy of 2.5 parts in 105. This scale and a datum of 979 671.86 mGal for Sydney A were adopted for Australia in 1973. The Soviet scale established for the ACL appears to be within 1 part in 104 of both the IGSN71 scale established for the Western Pacific Calibration Line by absolute determinations, pendulum measurements and international gravity meter comparisons, and the scale established for the Soviet Calibration Line by OVM pendulums. The Soviet scale for the ACL defines a milligal which is 1.5 parts in 104 larger than that defined by IGSN71 values for the ACL, and 5 parts in 104 larger than the 1965 Mean Australian Milligal that was used as an Australian milligal standard between 1965 and 1973. Both of these scales are partly based on Cambridge pendulum measurements made in Australia during 1950-51. These measurements are now thought to have been incorrect in scale. LaCoste, Romberg gravity meters have been used during six surveys along the whole or part of the ACL. The LaCoste observations have been reduced using the Soviet ACL scale and the new datum for Sydney A. The most probable values for airport gravity stations, calculated from the LaCoste results, have a precision of better than 0.01 mGal and are consistent to within experimental error with values calculated from the GAG-2 results. LaCoste observations reduced using the Soviet ACL scale give more accurate values for the gravity differences of the main intra-city ties and calibration ranges along the ACL.

A collection of palaeontological papers 1972 (bulletin 150)

In January 1970, after a two-year period of inactivity, Ulawun volcano, on the north coast of New Britain, erupted. Ulawun is a stratovolcano built of basaltic and low-silica andesite lava flows and pyroclastic rocks, most of which were erupted from a central vent; many of the lavas were partly fragmented during flow, and some unsorted elastics mav have been deposited by nuees ardentes.

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.

The Bonaparte Gulf Basin is a north-pitching syncline of Phanerozoic sediments, which are bounded to the south by Precambrian rocks and extend northward beneath the Timor Sea (Fig. 1). The landward part of the basin has been fragmented by faults, uplift, and erosion into a main outcrop area and three outliers. The eastern edge of the original depositional basin corresponds approximately with the present eastern margin, but the original extent to the south and west is unknown. Within the main outcrop is a Precambrian inlier, the Pincombe Inlier, which influenced deposition during the Upper Devonian and Lower Carboniferous. The main outcrop (Fig. 2) comprises Lower Cambrian volcanics, and Cambrian, Lower Ordovician, Upper Devonian, Carboniferous, Permian, Lower Triassic, and Lower Cretaceous sediments. The outliers contain only the lower part of this sequence, up to and including the lower part of the Upper Devonian.

This Atlas of isoseismal maps of Australian earthquakes contains the results of the ground intensity effects from all known Australian earthquakes for which adequate documentation is available. A total of 83 isoseismal maps are presented for 70 Australian earthquakes. The Atlas is arranged with each isoseismal map presented in chronological order, facing a page containing a brief description of the earthquake and the methods used to obtain the intensity data. References to the source of the map and to other publications that contain information on the earthquake's intensity are also given. The earliest map is from the July 1883 Mount Barker (SA) earthquake and the most recent from the November 1981 Suggan Buggan (NSW) earthquake. The largest recorded earthquakes from the Australian continent have occurred in Western Australia. These were the 1941 Meeberrie and 1968 Meckering events, which have magnitudes of about ML 7, and were felt at distances of about 900 and 800 kilometres from their respective epicentres. In South Australia, the 1897 Beachport earthquake (magnitude 6.5) produced the greatest shaking and was felt about 600 kilometres from the epicentre; in eastern Australia, the 1935 Gayndah (Qld), 1961 Robertson-Bowral (NSW), and 1973 Picton (NSW) earthquakes were felt out to about 400 kilometres and the 1918 Bundaberg (Qld) earthquake was felt at distances of about 650 km. The 1968 Meckering and June 1979 Cadoux earthquakes produced the highest observed ground shaking. Intensities of MM IX were experienced, and fault scarps, with throws of about a metre, extended over several kilometres for each earthquake. Intensities of MM VIII were recorded for the 1897 Beachport, 1902 Warooka, 1941 Meeberrie, 1949 Dalton-Gunning, and 1954 Adelaide earthquakes. Total damage caused by the June 1979 Cadoux earthquake was 3.8 million dollars (1979 prices) and the 1968 Meckering earthquake, 2.2 million dollars (1968 prices). The 1954 Adelaide earthquake caused 4 million pounds damage at 1954 prices.

Many of Australia's birds are unique to this continent, but none are more impressive than a group of giant ground birds, the Dromornithidae, one member of which may have exceeded in volume and weight any bird that has ever trod the surface of the earth. Although first discovered in the early 19th century, only two genera (Genyornis and Dromornis), both monotypic, had been recognized when work beginning in the 1950's in central Australia brought to light at least six new forms including three new genera (Barawertornis, Bullockornis, and Ilbandornis), described for the first time in this paper. Based almost entirely on post-cranial material, the Dromornithidae appear to be most closely related to the Casuariidae, the only other Australian ratite group, but before a satisfactory higher taxonomic allocation can be made, good cranial material is needed. Unfortunately, the maximum age of known dromornithid fossils is about 15-20 million years, and from that first record to the last in the late Pleistocene, only minor evolutionary changes are known to have occurred, namely: reduction of the forelimb, reduction of the medial digit of the foot, and development of hoof-like ungual phalanges on the foot. A much more fascinating evolutionary picture of this diverse group awaits future palaeontological discoveries.

The chemistry of groundwater in the regional recharge zones of Triassic and Carboniferous rocks in the upper Hunter River valley of New South Wales is strongly influenced by silicate and carbonate dissolution/precipitation reactions, ion exchange and the dispersion of aerosols in infiltrated rainfall. The Wollombi Coal Measures and Jerrys Plains Subgroup of the Wittingham Coal Measures west of the Muswellbrook Anticline constitute the regional groundwater transmission zones, and the processes having the greatest influence on the chemistry of their water are dissolution/precipitation reactions and oxidation of coals. The semi-confined aquifers of the Greta Coal Measures, Maitland Group, Dalwood Group, and Wittingham Coal Measures in the eastern and southern parts of the valley discharge into unconfined sand and gravel aquifers of the Hunter River floodplain. These Permian rocks are the source of the most saline water in the valley, and the chemistry of their groundwater is largely determined by oxidation of sulphides and molecular diffusion of connate marine salts, a legacy of periodic immersion by Permian ocean water. Disequilibrium indices for calcite, dolomite and dawsonite indicate that these carbonates are being precipitated today in the groundwater of the Central Lowlands provinces; they are being dissolved in the southern and western groundwater recharge zones and are in equilibrium with water of the northern recharge zone. The iron carbonates, siderite and ankerite, are a product of a palaeohydrochemical regime characterised by saline alkaline water rich in dissolved iron disseminated from gels originally accumulated in the Permian peat swamps, but these minerals are not being precipitated in modern upper Hunter River valley groundwater. The sulphate minerals, gypsum, thenardite and bloedite, occur extensively in salt efflorescences in the Permian rocks of the Central Lowlands, but their disequilibrium indices show that none of the minerals can be precipitated in the contemporary upper Hunter River valley groundwater by processes other than evaporative concentration. Models based on incongruent dissolution of feldspars allocate much of the upper Hunter River valley groundwater to the kaolinite stability field, which is consistent with the abundance of kaolinite as an authigenic mineral in the fractured rock aquifers. Silica and cations leached from the fractured rocks are accumulating in the groundwater sinks around the margins of the Hunter River floodplain, as indicated by the large proportion of groundwater in these areas which are in equilibrium with Ca-montmorillonite. Concentrations of C a 2 + , S i 0 2 and H C 0 3 ions in upper Hunter River valley groundwater approach log-normal distributions and these species are most highly identified with continental hydrochemical processes. In contrast, the four 'elements' constituting the bulk of solutes in ocean water, CI", N a + , SOj" and Mg2 + , are distributed in two modes: the low-concentration primary mode, representing the dissemination of these species from the continental solutes store, and the secondary high-concentration mode, reflecting diffusion and oxidation of marine inputs. On a province-wide scale, composition diagrams of solute behaviour identify the Wittingham Coal Measures to the east and south of Muswellbrook Anticline, the Greta Coal Measures, and the Maitland and Dalwood Groups as systems that can be approximated by simple linear mixing models between meteoric and oceanic water. Composition diagrams for the floodplain hydrochemical provinces show that the alluvial aquifers can be represented as mixing systems between Hunter River surface water and groundwater of the fractured-rock aquifers. Principal component analyses describe the chemical evolution of upper Hunter groundwater from the Permian marine transgression through to the present continental leaching regime for similar positions along flow lines in discharge zones, groundwater of the Greta C

The Proterozoic Mount Isa Inlier of northwestern Queensland is one of Australia's most important producers of copper, zinc, lead, and silver, accounting for over 40% of Australia's export earnings of these metals. Hence, it has been a focus of geological mapping and exploration for many years. BMR's interest began in the early 1950's, and by 1958 the entire inlier had been mapped at the broad reconnaissance level (1:250 000 scale) by joint BMR-GSQ (Geological Survey of Queensland) parties (Carter & others, 1961). This work established a stratigraphic framework for the inlier, and provided the first insight into its extremely complex structure. A more detailed (1:100 000 scale) second stage of mapping, again by joint BMRGSQ parties, began in 1969 and was largely completed by1980. This work extensively revised the stratigraphic picture, and the timing of major igneous events was determined using U-Pb geochronology. Blake (1987) synthesised the mapping results and prepared a 1:500 000 map of the entire inlier. The third BMR mapping stage began in 1983 and finished in 1989, and was concerned with detailed structural, penological (both igneous and metamorphic), sedimentological, and geochronological studies by BMR and BMR-supported university workers. The results of this work are presented as separate papers in this bulletin and as a set of individual geological maps at various scales on which most of the papers are based; the individual maps are synthesised into a 1:250 000 scale transect map which accompanies this bulletin. The maps are listed in the Table of Contents, and the locations of the mapped areas are shown in Figure 1. BMR is currently (1992) preparing a metallogenic analysis and Geographic Information System of the Mount Isa Inlier in ARC/INFO format (Wyborn & Gallagher, in preparation), which will incorporate the following digital datasets: the 1:500 000 scale geological map of Blake (1987); geochemical data; regional geophysical data; metallogenic data (Raymond & Fortowski, in press); and Landsat TM imagery.

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.