This CD contains a collection of reports on samples from Arafura Basin wells (biostratigraphy, organic petrology, fluid inclusions - GOI, organic geochemistry and geohistory modelling) generated by GA staff and by external contractors and collaborators based on new analyses carried out during 2004 and 2005.

Conodont Biostratigraphy of the upper Devonian reef complexes of the Canning Basin, Western Australia

Trilobite faunas are described from sections at Black Mountain, Mount Ninmaroo, Mount Datson, and Dribbling Bore, in the southern part of the Burke River Structural Belt on the eastern margin of the Georgina Basin, western Queensland: 96 species and subspecies are assigned to 51 genera and subgenera classified into 22 families and subfamilies. Seven genera, 5 subgenera, 46 species, and 3 subspecies are new: 28 species are left under open nomenclature.Eight taxa are of early Ordovician age, Datsonian to early Warendian. The remainder are late Upper Cambrian, ranging in age from the informally designated pre-Payntonian B interval to Payntonian. The Cambrian faunas are late Changshanian to early Wanwanian in terms of Asian stage nomenclature; latest Franconian and Trempealeauan with reference to North American stages; and range upwards from approximately Zone 5b (of Westergaard) when compared with the Atlantic-Baltic biostratigraphical scale. The most complete stratigraphical section is described at Black Mountain, where trilobite faunas are grouped into six successive assemblage-zones on the basis of specific range and association. In ascending order these zones are: Pseudagnostus clarki patulus with Caznaia squamosa, Pseudagnostus clarki prolatus with Caznaia sectatrix, Pseudagnostus bi/ax with Pseudagnostus denticulatus, Pseudagnostus clarki maximus with Pseudagnostus papilio, Sinosaukia impages, Pseudagnostus quasibilobus with Tsinania (Tsinania) nomas. A seventh zone, that of Mictosaukia perplexa, succeeds the quasibilobus-nomas Assemblage-Zone at Mount Datson and Dribbling Bore. Biostratigraphical subdivision has been facilitated by use of the Dice Similarity Coefficient and cluster analysis techniques. The faunal passage from latest Cambrian to earliest Ordovician, which is obscured by dolomitic intervals at Black Mountain, Mount Ninmaroo, and Mount Datson, is documented at Dribbling Bore, where the PayntonianDatsonian boundary, corresponding to the Cambrian-Ordovician boundary, is recognized by the incoming of the conodont assemblage-zone based on Cordylodus proavus. In the early parts of the sequences studied, pre-Payntonian B and early pre-Payntonian A intervals, trilobite assemblages have a high component (often more than half) of cosmopolitan elements, particularly Agnostina, Remopleuridacea, and Asaphacea. In the late pre-Payntonian A and Payntonian, endemic Asian shelf elements or their close relatives, particularly Saukiidae and Leiostegiacea, dominate the assemblages, often in excess of 80 percent of the faunas. Consequently, Asian taxa occurring in western Queensland are revised. Among the Agnostina, late Cambrian representatives of the genus Pseudagnostus occurring in Australia are divided into four species groups based on Pseudagnostus clarki Kobayashi, P. convergens Palmer, P. clavus Shergold, and P. bilobus Shaw. The morphology of these species is discussed in detail, and descriptions of both external testaceous and parietal surfaces are given wherever possible.

Four Basin Lithostratigraphy Charts: Offshore Northern Perth Basin Biozonation and Stratigraphy, 2012- Chart 38; Perth Basin Biozonation and Stratigraphy, 2012 - Chart 39; Gippsland Basin Biozonation and Stratigraphy, 2012 - Chart 40; Bight Basin Biozonation and Stratigraphy, 2012 - Chart 35

This Bulletin is the third of a series of Bulletins dealing with the palaeontology and stratigraphy of the Cambrian of Queensland, as well as of Aus.tralia in general. This Bulletin, dealing with the Mindyallan and its fauna, fills a hitherto bl~mk interval in the Australian Cambrian sequence and supplies amplifying information regarding the geological and biological history of the early Upper Cambrian in general. Originally, the palaeontology of 'the lower chert bed' of the O'Hara Shale was planned as a part of Bulletin 53 (Opik, 1961), but had to be postponed for technical reasons; subsequently the early Upper Cambrian stratigraphy was presented in Bulletin 64 (Opik, 1963), and all available information from all geological sources is now included in the present contribution. 1 wish to emphasize that all Mindyallan comprehendable forms so far collected are described, regardless of their state of preservation, but that some material remains indicating the existence of forms which need further collecting. T

Legacy product - no abstract available

Two samples of diatomite were recently received from Broken Hill Pty. Co. Limited for microscopic examination. They were from Nettle Creek, 9 miles north-east of Mt. Garnet and near Innot Hot Springs. The results of the microscopic examination are given in this report.

Sequence biostratigraphic analyses from five industry wells in the Northern Carnarvon Basin (NCB) are tied to seismic stratigraphic interpretations from an exceptional set of 3D and 2D seismic data. We document distribution patterns of ~286 benthic and 73 planktonic foraminiferal taxa in sidewall cores and ditch cuttings from Eocene to Pliocene intervals and supplement this with observations of other fossil groups, e.g., ostracods, bryozoa, coral and mollusc fragments, and lithological components, such as, authigenic calcite and quartz sands. Preservation of foraminiferal assemblages is extremely variable in Oligocene to latest Miocene stratigraphy, depending upon location of wells and interval investigated. Nonetheless, consistent, detectable faunal signals correlate between wells, and with prominent seismic horizons and sequences. The late Oligocene to middle Miocene is characterized by deeper-water benthic assemblages dominated by infaunal taxa and higher planktonic to benthic ratios. A cluster of stratigraphic events in the middle Miocene, including turnover in benthic foraminifera, is interpreted to record a regional flooding event (equivalent to TB2.3) at the beginning of the mid Miocene climatic optimum (~16-14.5 Ma). Following this event, seismically-defined geomorphic features include intensive karstification and incision on the clinoform front. All wells show a major transition to shallow-water, warm conditions on the shelf in the middle and late Miocene, with benthic assemblages dominated by larger foraminifera. This transition occurs progressively later in more basinward wells and appears to be a result of progradation. Geomorphic features in the late middle Miocene (~12 Ma), identified from 3D seismic analyses, show an intensification of earlier gully formation, resulting in submarine canyons. Detailed analyses of faunal patterns also provide evidence of higher-frequency sea-level fluctuations (0.5-3 Ma), not detected in seismic stratigraphic patterns.

Legacy product - no abstract available

Legacy product - no abstract available