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  • The Bowen Basin is a Permian to Triassic basin extending from Collinsville in the north to Goondiwindi in the south, where it is overlapped by Mesozpic rocks of the Surat Basin (the easternmost extension of the Great Artesian Basin). Beneath the cover the Bowen Basin may be continuous with the Sydney Basin. The northwestern boundary is the pre-Permian Clermont Stable Block, that in the east is formed by the Strathmuir Synclinorium and the Eungella-Cracow Mobile Belt, where pre-Permian rocks are faulted against or overlain by steeply dipping Permian sediments, through which they penetrate as inliers. The western boundary is the Birkhead axis, which separates the Bowen Basin from the Galilee Basin. Between these boundaries lies the structural basin that Derrington (1962) called the Bowen Synclinorium: we prefer the more general term Bowen Basin. Most of the stratigraphy of the basin has been described in detail in published reports, to which reference is made, and descriptive material is therefore kept to a minimum in this Bulletin; only rock units not adequately described elsewhere, or re-interpreted in the light of more recent work, are described here. Figure 1 lists all the main rock units in the order in which they will be discussed. The map area (PI. 1; 1:500,000 geological map) is largely contained within the Fitzroy and Burdekin-Townsville Regions. The physical and cultural geography of these regions is set out in a series of maps and booklets issued by the Commonwealth Department of National Development, which have been freely drawn on for the data that , follow. The towns, culture, and physiographic features of the area are shown in Figure 2. The mapped area is about 150,000 km2 . The coastline extends some 250 km north and south of Mackay. Rockhampton, the largest town in central Queensland, lies 55 km east of the mapped area. The regional survey was a joint project by the Commonwealth Bureau of Mineral Resources and the Geological Survey of Queensland.

  • A collection of papers on the metallogenic provinces and mineral deposits in the southwestern pacific.

  • Three zones of retrograded crystalline basement rocks have been delineated in central Australia. One, along the southwestern margin of the Amadeus Basin, was deformed about 600 m.y. ago during the Petermann Ranges Orogeny. Two one north of the Amadeus Basin, the other north of the Ngalia Basin were deformed during the Carboniferous Alice Springs Orogeny. Each retrograded zone is highly deformed and is flanked on one side by folded and thrust sedimentary rocks and on the other by granulite and amphibolite facies rocks. The high-grade rocks appear to have resulted from several metamorphic episodes in the Precambrian. A major gravity gradient is associated with each retrograded zone; the Bouguer anomaly highs generally occur over the areas of high-grade metamorphic rocks, and the lows over the sedimentary basins and retrograded rocks. In general, the deformed and retrograded zones are moderately to gently dipping. The gravity gradients are so wide and steep that to explain them the deformed zones must pass through the crust into the mantle beneath. The crust and mantle above each deformed zone have been upthrust, bringing granulite facies rocks to the surface and producing Bouguer gravity anomaly highs over the uplifted lower crust and mantle. The deformed zones are similar to the subduction zones that may develop on the margins of continents, but there is no evidence of continental collision in central Australia when they were formed, and they are regarded rather as possible examples of intracontinental plate reactions. They may have extended right across the continent or may terminate against strike-slip (transform) faults. A possible site for such a transform fault in Western Australia is discussed, but its existence is speculative.

  • Isopach, structure contour, and palaeo-geological maps illustrate the geological development of the southern Taroom Trough and the lower part of the Surat Basin sequence. The meridional southern Taroom Trough, 50,000 km2 in area, is a southerly subsurface extension of the outcropping Bowen Basin. It is fault-bounded to the east and plunges northward. The maximum thickness of sedimentary fill increases northward from less than 400 m to 10,000 m, and consists of Lower Permian marine sediments, Upper Permian coal measures, Lower Triassic redbeds, and Middle Triassic stream sediments. The trough's present western margin is depositional, but the faulted eastern margin started to form in the Late Permian in the south and in the Early Triassic in the north; movement ceased in the Early Triassic in the south and in the Late Triassic in the north. Tectonic movements did not recur until Late Jurassic time. Late Triassic erosion preceded deposition of Surat Basin sediments. These sediments extended over ever wider areas, even the basal sands spreading far beyond the Taroom Trough. The fully-developed Surat Basin is 300,000 km2 in area, and contains up to 2500 m of dominantly continental Jurassic sediments and dominantly marine Lower Cretaceous sediments. Lower Jurassic stream sediments (the main petroleum producers of the basin) are thickest and coarsest above the Taroom Trough, suggesting steady subsidence and compaction of the trough sediments. By the Late Jurassic this compaction had virtually ceased, and epeirogenic uplift had given the basin its present shape, with the Mimosa Syncline (above the Taroom Trough) and the south-westerly-trending Dirranbandi Syncline (above a basement depression) being major structural features. Petroleum, which is probably derived from both Permian and Jurassic sources, is most abundant in the Lower Jurassic sandstone on either side of the Mimosa Syncline. Some aspects of the migration and trapping of Permian petroleum are discussed, and it is suggested that the Lower Jurassic Hutton Sandstone in the virtually unexplored Bollon area could be prospective.

  • A broad ridge of Precambrian and Palaeozoic igneous and metamorphic rocks extends for 450 km along the east side of Cape York Peninsula, from the Mitchell River in the south to Temple Bay. From Cape York a submerged ridge of Palaeozoic igneous rocks extends across Torres Strait to Papua. The metamorphic rocks crop out in four separate areas, but are all probably part of the same Precambrian sedimentary sequence. They have been subjected to high-temperature/lowpressure regional metamorphism, and the metamorphic grade increases eastwards from phyllite of the greenschist facies to gneiss of the amphibole facies. They consist mainly of mica schist and quartzite, with local occurrences of greenstone, calc-silicate rocks, marble, and iron-rich rocks, and are intruded by dolerite in the south. The Cape York Peninsula Batholith is composed of adamellite and subordinate granodiorite and granite. It is intrusive into the discontinuous belt of metamorphic rocks over a distance of at least 400 km. The age of the batholith is uncertain, but preliminary isotopic analyses indicate that it is probably middle Palaeozoic. In the Lower Carboniferous coal-bearing sediments were laid down in small basins. The thick sheets of acid welded tuff and subordinate lavas in Torres Strait, which are intruded by large bodies of granite and porphyritic microgranite, are probably Carboniferous, and the acid pyroclastics and associated high-level granites south of Temple Bay are Carboniferous or Permian. In the Mesozoic, coarse sandstone and conglomerate followed by finer sediments were laid down in the trough between the two basement ridges. Tertiary uplift on faults along the east side of the peninsula resulted in the deposition of poorly consolidated sandstone and conglomerate. A plug of olivine nephelinite was emplaced near the faults, and in the Pleistocene olivine basalt lava and pyroclastics were erupted from small volcanoes in the northeastern part of Torres Strait. Most of the main structures in the peninsula, such as the fold axes and foliation in the metamorphics, the faults, and the long axis of the batholith, have a northerly trend. The Palmerville Fault is a major structure which has been active from Silurian time onwards. Alluvial and reef gold were mined extensively in Cape York Peninsula and in Torres Strait late in the 19th century, and small quantities of wolfram and alluvial tin have also been won. The deposits of iron and manganese near Iron Range and the silica sand on the Mesozoic sediments north of Temple Bay have not yet been exploited. Traces of antimony, arsenic, copper, lead, zinc, and molybdenum have been reported, and occurrences of bauxite, coal, mica, heavy-mineral beach sand, and limestone are known.

  • A collection of palaeontological papers, 1970-71.

  • Legacy product - no abstract available