Journal articles on the topic 'Carnarvon Region'

The Northern Carnarvon Basin is one of Australia’s most prolific hydrocarbon basins. Overpressure has been encountered in numerous wells drilled in the Northern Carnarvon Basin. Knowledge of overpressure distribution is important for drilling and exploration strategies, and understanding the origin of overpressure is essential for applying reliable pore pressure prediction techniques. Unconventional pore pressure indicators—primarily drilling kicks and the presence of connection gas—were used to improve an updated distribution of overpressure and to investigate the origin of overpressure in the Northern Carnarvon Basin. This unconventional dataset was compiled from 45 wells. Overpressures are observed in 40 wells and tend to occur near, or on, the Rankin Platform, Alpha Arch, and Barrow Trend. The presence of overpressure in this area coincides with the region of maximum Cenozoic deposition. Overpressured strata in the Northern Carnarvon Basin occurs through a wide stratigraphic range, from Late Triassic to Paleocene sequences. Generally, post Paleocene sequences in the Northern Carnarvon Basin are considered to be normally pressured. Porosity-vertical effective stress analysis in shale lithologies was used to investigate the origin of overpressure in the Northern Carnarvon Basin. Porosity-vertical effective stress plots from 28 wells in the Northern Carnarvon Basin identified 20 wells where the overpressure appears to be generated by disequilibrium compaction, and eight wells where the overpressure appears to be generated by a component of fluid expansion. Disequilibrium compaction mechanisms were the predominant cause of overpressure in wells around the Rankin Platform and areas located further away from the coast. Conversely, fluid expansion mechanisms were the predominant cause of overpressure in wells around the Alpha Arch and Bambra Trend, and an area located closer to the coast. These results broadly confirm those obtained from earlier studies and highlight the usefulness of kick and connection gas data in overpressure analysis.

This study investigates the fire regime for the arid Carnarvon Basin region of Western Australia using remotely sensed imagery. A fire history database was constructed from satellite images to characterise the general fire regime and determine any effect of vegetation types and pre-fire weather and climate. The study area was divided into two sections (northern and southern) due to their inherently different vegetation and climate. A total of 23.8% (15,646 km2) of the study area was burnt during the 39-year study period. Heathland vegetation (54%) burnt the most extensively in the southern study area, and hummock grasslands (68%) in the northern. A single, unusually large fire in 2012 followed exceptional rains in the previous 12 months and accounted for 55% of the total burnt area. This fire burnt mainly through Acacia shrublands and woodlands rather than hummock grasslands, as normally experienced in the northern study area. Antecedent rainfall and fire weather were found to be the main meteorological factors driving fire size. Both study areas showed a moderate to strong correlation between fire size and increased pre-fire rainfall in the year preceding the fire. Predicted future changes in climate may lead to more frequent and higher intensity fires.

The under-explored Carnarvon Terrace is situated offshore of the Cape Range area in the Carnarvon Basin near the boundary of the Gascoyne and Exmouth Sub-basins. The stratigraphy of the area is controlled by only two wells (Pendock-1, Yardie East-1), but several onshore wells aid interpretation of seismic data.Understanding of the structural evolution of the region is facilitated by interpretation of a high-resolution non-exclusive seismic survey acquired by Geco-Prakla in 1993 (GPCTR-93 Survey).Three major tectonic stages are responsible for the structural configuration of the region:Late Palaeozoic extension in the Gascoyne Sub-basin;continental break-up between Australia and Greater India which took place along a major fracture marked by the Flinders-Long Island-Learmonth fault system active in Late Triassic and Early Jurassic times; andthe collision between Australia and Asia that commenced in Miocene times and is continuing to the present day. This event, marked by wrench and compressional structures, and often reactivation of older structures, is one of the most economically important in Australian geological history.From a regional prospectivity viewpoint at least three plays are worthy of further investigation.

Infauna are important in many ecological processes but have been rarely considered in biodiversity assessments of coral reefs and surrounding areas. We surveyed infaunal assemblages and associated environmental factors (depth, seabed reflectance, sediment characteristics) in three areas (Mandu, Point Cloates, Gnaraloo) along the Carnarvon Shelf, Western Australia. This region supports Ningaloo Reef, a relatively pristine coral reef protected by the Ningaloo Marine Park and a Commonwealth marine reserve. Macrofauna were sampled with a Smith-McIntyre grab and sieved through 500 µm. A total of 423 species and 4036 individuals was recorded from 145 grabs, with infauna accounting for 67% of species and 78% of individuals. Rare species (≤2 individuals per species) represented 42% of the total assemblage. Assemblages were significantly different among all three areas, with the most distinct recorded from the southern-most area (Gnaraloo). Although assemblages varied significantly with depth and sediment composition (mud and gravel), these relationships were weak. Results from the current study broadly quantify macrofaunal diversity in the region and identify potential spatial and environmental patterns which will help inform future marine management plans, including the provision of baseline information to assess the efficacy of protected areas in soft-sediment habitats adjacent to coral reefs.

The Perth, Carnarvon, Browse, and Bonaparte basins contain Permian shallowmarine carbonates. Interbedded with clastic oil and gas reservoirs in the northern Perth Basin (Wagina Formation), and gas reservoirs in the Bonaparte Basin (Cape Hay and Tern formations), these carbonates also have the potential to contain significant hydrocarbon reservoirs. Limestone porosity may be related to the primary depositional fabric, or secondary processes such as dolomitisation, karstification, and fracturing. However, in the Upper Permian interval of the North West Shelf and northern Perth Basin, where there are no indications of significant preserved primary porosity in the limestones, all known permeable zones are associated with secondary porosity. Fractured Permian carbonates have the greatest reservoir potential in the Timor Sea. Tests of fractured Pearce Formation limestones in Kelp Deep–1 produced significant quantities of gas, and a test of fractured Dombey Formation limestone in Osprey–1 flowed significant quantities of water and associated gas. Minor fracture porosity was associated with gas shows in dolomitic limestones in Fennel–1 in the Carnarvon Basin, and fractures enhance the reservoir in the Woodada Field in the northern Perth Basin. Karst formation at sub-aerial unconformities can lead to the development of secondary porosity and caverns, as in the Carnarvon Basin around Dillson–1. Minor karst is also developed at the top Dombey Formation unconformity surface in the Timor Sea region.

Recent studies are increasingly shifting away from viewing drug and alcohol problems as individual medical disorders and recognising the significant role of environmental and community factors. In keeping with this, the Partysafe project, being implemented in the remote North West town of Carnarvon in Western Australia (WA), is utilising a community mobilisation approach to reducing harm associated with alcohol consumption in private residences. Carnarvon, like most rural communities in WA, has a higher rate of alcohol consumption than in the metropolitan region, hence its selection as the target site. An additional reason for selecting a remote town was the belief that national and state level prevention strategies cannot always be successfully implemented due to a region?s unique social and environmental influences. This paper discusses the community mobilisation methodology, giving a practical insight into the specific interventions and evaluation techniques developed for the Partysafe project. The process of identifying community-based alcohol issues and the problems associated with implementation and evaluation are illustrated. A combination of archival quantitative data and community based qualitative data will be used to assess the project?s success. Collection and use of this data is also practically depicted.

We generated a multi-locus phylogeny to test monophyly and distributional limits in Australian toadlets of the genus Uperoleia from the western arid zone of Australia. The molecular data were used in combination with a detailed assessment of morphological variation and some data on call structure to complete a taxonomic revision of the species that occur in this region. Our work reveals the existence of not two but five species in the region. Uperoleia russelli is restricted to the Carnarvon and Gascoyne Regions south of the Pilbara. Uperoleia micromeles is distributed from the Tanami Desert through the Great Sandy Desert and along the northern edge of the Pilbara. Uperoleia talpa was previously believed to be a Fitzroyland region endemic but it is further distributed along Dampierland and into the Roebourne Plain. Uperoleia glandulosa is a larger species than previously described as well as a greater habitat generalist, inhabiting the rocky Pilbara region and the sandy region around Port Hedland. We also describe a new species, U. saxatilis sp. nov., endemic to the Pilbara craton.

A small, but significant fraction of wells drilled in the Northern Carnarvon Basin have encountered problems with overpressure: better pore pressure prediction would improve safety and economy for drilling operations. In the Northern Carnarvon Basin the occurrence of overpressure and likely mechanisms are under investigation as part of the Australian Petroleum Cooperative Research Centre (APCRC) Research Program on Pore Pressure Prediction. Previous workers have proposed a number of mechanisms as the main cause of overpressure including undercompaction, hydrocarbon generation, horizontal stress and clay reactions.A preliminary regional study was undertaken incorporating over 400 well completion reports which identified approximately 60 wells with mud weights greater than 1.25 S.G. A subset of these wells was investigated and more reliable but much scarcer pressure indicators such as kicks or direct pressure measurements were examined. Depth-pressure profiles of wells across the region are variable and commonly show pressure compartmentalisation. Using a range of indicators, it was observed that overpressured strata in the Barrow Subbasin:occur over a wide depth range (2,500 to 4,000+ mbsl);occur over a wide stratigraphic range (Late Triassic to Late Cretaceous);are not regionally limited by major structural boundaries;are associated with sequences dominated by finegrained sediments with variable clay mineralogy; and in depositionally, or structurally, isolated sandstones; andmainly to the west of the Barrow and Dampier Subbasins around the Alpha Arch and Rankin Trend, coinciding with thickest Tertiary deposition.Previous published work in the study area has tended to support hydrocarbon generation as the primary cause of overpressure, though more recent publications have emphasised compaction disequilibrium. The log response (DT, RHOB and NPHI) of overpressured clay-rich strata has been investigated to constrain the type of overpressure mechanism. A normal compaction trend has been derived for four stratigraphic groupings; Muderong Shale, Barrow Group, Jurassic and Triassic. All overpressure occurrences were accompanied by an increase in sonic transit time. Not all wells have suitable log data for evaluation, but all stratigraphic groups show some evidence of elevated porosity associated with overpressure consistent with disequillibrium compaction as a dominant mechanism. Overpressures in the Barrow Group in Minden-1 and the Jurassic section within Zeepaard–1 do not have accompanying porosity anomalies suggesting a different overpressure mechanism model is needed.

Key business indicators show an upward trend in exploration activity in Australia during 2006. The year was marked by fluctuating high oil prices, a strong uptake of acreage in most basins, and increased levels of drilling activity and seismic acquisition. Market demand for product, production infrastructure and the fruition of several development projects have pushed the level of exploration activity in both offshore and onshore basins. Despite this trend and the spread of tenements, almost all petroleum discoveries made during 2006 were located within 15 km of existing (but often undeveloped) fields.The Carnarvon Basin continued to be the focus of most offshore exploration activity during 2006, with the highest levels of 3D seismic acquisition and exploration/appraisal/development drilling in the country. Discoveries in the Carnarvon Basin also covered the broadest range of water depths—extending from the oil and gas discoveries made by Apache on the inboard margin of the Barrow Subbasin, to the deepwater gas discoveries at Clio–1 and Chandon–1 by Chevron. Several large gas discoveries were made in the Carnarvon and Bonaparte basins and provide significant tie-back opportunities to existing and planned infrastructure. The Bonaparte Basin also saw significantly increased levels of 2D and 3D seismic acquisition during 2006. Onshore, the Cooper/Eromanga basins continued to experience the highest level of drilling activity and seismic acquisition, while maintaining an overall high drilling success rate. For the first time in many years, data acquisition also occurred in frontier basins like the Daly (Northern Territory), Darling (New South Wales), Tasmanian (Tasmania) and Faust/Capel basins (Lord Howe Rise region).Coal seam methane (CSM) exploration maintained a strong performance in 2006, particularly in Queensland, while South Australia, Queensland and Victoria continue to lead the way with large tracts of acreage gazetted for geothermal energy exploration.

The region of the North West Shelf dealt with in this paper is underlain by three of the four basins which make up the Westralian Superbasin. The Bonaparte Basin lies outside the scope of this paper; the other basins are the Browse Basin, the offshore Canning Basin, here named the Western Canning Basin, and the offshore Carnarvon Basin, here called the Northern Carnarvon Basin. Sediments belonging to ten depositional sequences (Pz5, Mzl to Mz5, and Czl to Cz4) are present in the basins, the oldest being of Late Carboniferous and Permian age (Pz5).Deposition commenced in rift (interior fracture) basins under fluvial/deltaic conditions in the Late Permian/Early Triassic (Mzl), when the North West Shelf was part of Gondwana. Continental breakup took place in the Middle Jurassic (breakup unconformity between Mz2 and Mz3), and marine conditions prevailed over the Westralian Superbasin thereafter, with deposition taking place in a marginal sag setting. Siliciclastic sediments gave place to carbonates in the Late Cretaceous (Mz5) as the Indian Ocean grew larger.Parts of the area have been under permit since 1946, and to date some 227 exploration wells have been drilled. The most intensive exploration has taken place in the Northern Carnarvon Basin (191 wells), followed by the Browse Basin (20 wells), and Western Canning Basin (16 wells). Thirty- four economic and potentially economic discoveries have been made. The main target reservoirs are Triassic, Jurassic and Cretaceous, and the regional seals are Triassic and Cretaceous. The fields are of two types: pre- breakup unconformity (mainly tilted horst blocks), and post- breakup unconformity (usually four- way dip closures). Of the five producing fields, the North Rankin Gas Field is a pre- breakup field, while the four oil fields (Barrow, Harriet, South Pepper and North Herald) are all post- breakup.

An extensive volume of 3D seismic data over a number of oil and gas fields in Australia's North West Shelf and Gippsland Basin has been examined for evidence of the effects of hydrocarbon migration and/or leakage. For comparative purposes, 2D and 3D data have also been studied over a number of adjacent traps, including dry traps and partially to completely breached accumulations. Fields and traps investigated include Bayu-Undan, Jabiru, Skua, Swift and Tahbilk in the Bonaparte Basin, Cornea in the Browse Basin, North Rankin, Chinook, Macedon, Enfield and Zeewulf in the Carnarvon Basin, and Kingfish in the Gippsland Basin. The principal goal of the study is to provide representative case studies from known fields so that, in undrilled regions, the exploration uncertainties associated with the issues of hydrocarbon charge and trap integrity might be reduced.Direct indicators of hydrocarbon migration and/or leakage are relatively rare throughout the basins studied, though the discoveries themselves characteristically show seismic anomalies attributable to hydrocarbon leakage. The nature and intensity of these hydrocarbon-related seismic effects do, however, vary dramatically between the fields. Over traps such as Skua, Swift, Tahbilk and Macedon, they are intense, whereas over others, for example Chinook and North Rankin, they are quite subtle. Hydrocarbon-related diagenetic zones (HRDZs), which had been identified previously above the reservoir zones of leaky traps within the Bonaparte Basin, have also been recognised within the Browse, Carnarvon, Otway and Gippsland Basins. HRDZs are the most common leakage indicators found and are identified easily via a combination of high seismic amplitudes through the affected zone, time pull-up and degraded stack response of underlying reflectors. In some cases (the Skua and Macedon Fields), the HRDZs actually define the extent of the accumulations at depth.Anomalous, subtle to strong, seismic amplitude anomalies are associated with the majority of the major fields within the Carnarvon Basin. The strength and location of the anomalies are related to a complex interplay between trap type (in particular four-way dip-closed versus fault dependent), top seal capacity, fault seal integrity, and charge history. In some areas within the Carnarvon, Browse and Bonaparte Basins, shallow amplitude anomalies can be related directly to gas chimneys emanating from the reservoir zone itself. In other instances, the continuous migration of gas from the reservoir has produced an assortment of pockmarks, mounds and amplitude anomalies on the present day sea floor, which all provide evidence of hydrocarbon seepage. In the Browse Basin, strong evidence has been found that many of the modern carbonate banks and reefs in the region were initially located over hydrocarbon seeps on the palaeo-seafloor.The examples and processes presented demonstrate that the analysis of hydrocarbon leakage indicators on seismic data can help to better understand exploration risk and locate subtle hydrocarbon accumulations. In mature exploration provinces, this methodology may lead to the identification of subtle accumulations previously left undetected by more conventional methods. In frontier regions, it can help to identify the presence of a viable petroleum system, typically the principal exploration uncertainty in undrilled regions.

Natural fractures can be identified in wellbores using electric resistivity image logs; however, the challenge of predicting fracture orientations, densities, and probable contribution to subsurface fluid flow away from the wellbore remains. Regional interpretations of fracture sets are generally confined to areas featuring an extensive reservoir analog outcrop. We have made use of extensive data sets available in Western Australia’s Northern Carnarvon Basin to map subsurface natural fractures, contributing to a regional understanding of fracture sets that can be applied to broader parts of the basin. The Northern Carnarvon Basin is composed of distinct structural domains that have experienced differing tectonic histories. Interpretation of regional fractures was achieved through an integrated approach, incorporating electric resistivity image logs from 52 Carnarvon Basin wells and seismic attribute analysis of two 3D seismic data sets: Bonaventure_3D ([Formula: see text]) and HC_93_3D ([Formula: see text]). Integration of these two data sets allows for a regionally extensive identification of natural fractures away from well control. Fractures of differing age and character are identified within the basin: Outboard areas are dominated by fractures likely to be open to fluid flow that are parallel to subparallel to the approximately east–west present-day maximum horizontal stress, providing possible flow conduits between potential damage zones identified alongside the north–northeast/south–southwest-striking faults that constitute the major structural trend of the basin, and inboard areas dominated by northeast–southwest to north–northeast/south–southeast fractures formed in fault damage-zones alongside normal, and inverted-normal, faults at those orientations. Finally, fractures observed in wells from the Rankin Platform and Dampier Subbasin occur at neither of these orientations; rather, they closely parallel the strikes of local faults. Additionally, variation is seen in fracture strikes due to isotropic present-day stress magnitudes. This methodology extends fracture interpretations from the wellbore and throughout the region of interest, constituting a regional understanding of fracture sets that can be applied to broader parts of the basin.

If the state of Queensland can be said to have true "uplands", then they are to be found in the southern and central region of the state in that place Archibald Meston (1895) called the "Home of the Rivers". There, some 400km inland from Australia's eastern coast and some 600km south of the Tropic of Capricorn, the uplifted and heavily weathered Triassic sandstones form a conspicuous link in the north-south trending mountains collectively referred to as "The Great Dividing Range". These ancient sandstones seldom rise above 650m elevation, and never more than the prominence of Black Alley Peak (Mt. Ackland) at 1000m. Rather, the range here achieves its mass and character by being broad and ruggedly dissected. Plateaus and mesas with sharp precipitous cliffs commingle with alluvial flats, seasonal creeks and the headwaters of several important rivers such as the Dawson, Warrego, Maranoa and Barcoo.

RadarSat and ERS Synthetic Aperture Radar (SAR) satellite data have been used for oil slick mapping as part of a systematic interpretative study of the offshore Canning Basin, as well as part of the northern Carnarvon Basin, extending from the inner shelf to the abyssal plain. These seepage data have been integrated with regional geological data, more than 12,000 km of reprocessed Airborne Laser Fluorosensor (ALF) survey data, seismic DHI indicators, water column geochemical sniffer data, potential field data, earthquake data and 2D Petromod basin modelling, to provide new insights into the region’s petroleum prospectivity and key exploration risk factors.From a prospectivity viewpoint, this study has highlighted several areas and processes. Firstly, it is clear that overpressure in the region is principally controlled by the thickness of the Tertiary carbonate wedge and we predict that overpressure may be present in parts of the deeper water Canning Basin. Secondly, the offshore Canning Basin contains a relatively low density of SAR-mapped oil slicks, though this appears to be due to a combination of factors, namely a paucity of vertical conduits for leakage, a predominantly condensate-prone charge and a small slick size.Significantly, several as-yet untested areas emerge from our observations. In the offshore Canning Basin, a 'window' exists in about 1,500–2,500 m of water, where the Triassic source rocks are particularly well placed for liquids generation. Morever, a large area in a radius some 20–80 km outboard of the Bedout High, also appears to have significant untested liquids potential, with respect to sourcing from the Triassic. The shallow section through this region contains a vast area with abundant seismically mapped gas chimneys and other seepage indicators, supporting the conclusions from the remote sensing and basin modelling of significant hydrocarbon charge in this region. Finally, the study indicates that liquids have been generated within the Palaeozoic section of the Bedout Sub-basin.

In 2008–9, under the Offshore Energy Security Program, Geoscience Australia (GA) acquired 650 km of seismic data, more than 3,000 km of gravity and magnetic data, and, dredge samples in the southern Carnarvon Basin. This area comprises the Paleozoic Bernier Platform and southern part of the Mesozoic Exmouth Sub-basin. The new seismic and potential field data provide a new insight into the structure and sediment thickness of the deepwater southernmost part of the Exmouth Sub-basin. Mesozoic depocentres correspond to a linear gravity low, in water depths between 1,000–2,000 m and contain between 2–3 sec (TWT) of sediments. They form a string of en-echelon northeast-southwest oriented depressions bounded by shallow-dipping faults. Seismic data indicates that these depocentres extend south to at least 24°S, where they become more shallow and overprinted by volcanics. Potential plays in this part of the Exmouth Sub-basin may include fluvio-deltaic Triassic sandstone and Lower–Middle Jurassic claystone source rocks sealed by the regional Early Cretaceous Muderong shale. On the adjoining Bernier Platform, minor oil shows in the Silurian and Devonian intervals at Pendock–1a indicate the presence of a Paleozoic petroleum system. Ordovician fluvio-deltaic sandstones sealed by the Silurian age marine shales, Devonian reef complexes and Miocene inversion anticlines are identified as potential plays. Long-distance migration may contribute to the formation of additional plays close to the boundary between the two provinces. With a range of both Mesozoic and Paleozoic plays, this under-explored region may have a significant hydrocarbon potential.

The Beagle Sub-basin is situated in the northernmost Carnarvon Basin, northeast of Dampier, West Australia. Twenty years of exploration in the sub-basin has yielded disappointing results, and despite the drilling of ten wells, the area is considered an under-explored region of the Northern Carnarvon Basin. A regional study of open-file geophysical and geological data from the Beagle Sub-basin was undertaken in anticipation of gazettal of the area in late 1992.Regional mapping of structural elements in the basin included:a complex, E/W to NE/SW-trending basin margin fault system;N/S-trending intra-basin horsts (Sable, Ronsard and Picard Blocks);an E/W to NE/SW-trending trough system (Cossigny and Beagle Troughs); and,Outer Basin PlatformFive unconformity-bounded megasequences of Triassic to Cretaceous age were identified and evaluated with regard to depositional setting, reservoir, source and seal potential. Palaeogeographic maps were produced for four time intervals and relate basin development and stratigraphy to regional eustatic cycles.Traps in the basin were largely developed during the Triassic to Middle Jurassic period of rifting, and range from pre-breakup fault blocks to post-breakup sands that developed along the margins of emergent structural highs. Potential source intervals range in age from Early Triassic (Locker Shale) to Late Jurassic. Migration and entrapment of hydrocarbons from the principal source areas (the Cossigny and Beagle Troughs) is largely dependent on effective pathways and the presence of a regional Aptian age seal. Extensive wrench reactivation in the Miocene has occurred along the basin margin fault system, and may breach existing traps as well as create new plays.

The Roebuck Basin is a sparsely explored, frontier province located between the Carnarvon and Browse basins on Australia's North West Shelf. Mapping of the main structural and depositional elements of the basin has led to the identification of new features and elucidated the basin's tectonic history.The newly-identified Oobagooma High is a 25 km wide north-south oriented, elongate structure that separates the Oobagooma and Rowley sub-basins at the Palaeozoic level. This structure links with the Bedout High to form a major hinge zone that stretches across the entire basin.In the study area, three sub-divisions of the Fitzroy Movement are observed which have been termed Fitzroy Movement I, II and III, of Middle Triassic, Late Triassic and Early Jurassic ages. A previously unidentified breakup event linked to Fitzroy Movement III in the Early Jurassic is inferred from the stratal geometries in the basin.The region lacks a source rock equivalent to the Upper Jurassic Dingo Claystone of the contiguous Carnarvon Basin. However, Lower Triassic marine shale and deltaic sands are well developed in the Bedout Sub-basin and based on the results of forward stratigraphic modelling using SEDPAK™ software and sequence stratigraphic correlations these sediments, have high source potential over most of the untested Rowley Sub-basin. Possible Jurassic source rocks in the Roebuck Basin were deposited under fluvio-deltaic conditions during waning thermal sag. Thinly developed sapropel zones exist in the Bedout Sub-basin but potential exists for greater thicknesses in the Rowley Sub-basin. This potential is suggested by the seismic character, sedimentary architecture and sedimentary modelling of Lower Jurassic rocks in the basin. Preliminary thermal modelling indicates that source rocks would have generated significant hydrocarbons from Middle Jurassic to the present. Timing of generation is favourable for trap formation.

The Barrow and Dampier Sub-basins of the Northern Carnarvon Basin developed by repeated reactivation of long-lived basement structures during Palaeozoic and Mesozoic tectonism. Inherited basement fabric specific to the terranes and mobile belts in the region comprise northwest, northeast, and north–south-trending Archaean and Proterozoic structures. Reactivation of these structures controlled the shape of the sub-basin depocentres and basement topography, and determined the orientation and style of structures in the sediments.The Lewis Trough is localised over a reactivated NEtrending former strike-slip zone, the North West Shelf (NWS) Megashear. The inboard Dampier Sub-basin reflects the influence of the fabric of the underlying Pilbara Craton. Proterozoic mobile belts underlie the Barrow Sub-basin where basement fabric is dominated by two structural trends, NE-trending Megashear structures offset sinistrally by NS-trending Pinjarra structures.The present-day geometry and basement topography of the basins is the result of accumulated deformation produced by three main tectonic phases. Regional NESW extension in the Devonian produced sinistral strikeslip on NE-trending Megashear structures. Large Devonian-Carboniferous pull-apart basins were introduced in the Barrow Sub-basin where Megashear structures stepped to the left and are responsible for the major structural differences between the Barrow and Dampier Sub-basins. Northwest extension in the Late Carboniferous to Early Permian marks the main extensional phase with extreme crustal attenuation. The majority of the Northern Carnarvon basin sediments were deposited during this extensional basin phase and the subsequent Triassic sag phase. Jurassic extension reactivated Permian faults during renewed NW extension. A change in extension direction occurred prior to Cretaceous sea floor spreading, manifest in basement block rotation concentrated in the Tithonian. This event changed the shape and size of basin compartments and altered fluid migration pathways.The currently mapped structural trends, compartment size and shape of the Barrow and Dampier Sub-basins of the Northern Carnarvon Basin reflect the “character” of the basement beneath and surrounding each of the subbasins.Basement character is defined by the composition, lithology, structure, grain, fabric, rheology and regolith of each basement terrane beneath or surrounding the target basins. Basement character can be discriminated and mapped with mineral exploration methods that use non-seismic data such as gravity, magnetics and bathymetry, and then calibrated with available seismic and well datasets. A range of remote sensing and geophysical datasets were systematically calibrated, integrated and interpreted starting at a scale of about 1:1.5 million (covering much of Western Australia) and progressing to scales of about 1:250,000 in the sub-basins. The interpretation produced a new view of the basement geology of the region and its influence on basin architecture and fill history. The bottom-up or basement-first interpretation process complements the more traditional top-down seismic and well-driven exploration methods, providing a consistent map-based regional structural model that constrains structural interpretation of seismic data.The combination of non-seismic and seismic data provides a powerful tool for mapping basement architecture (SEEBASE™: Structurally Enhanced view of Economic Basement); basement-involved faults (trap type and size); intra-sedimentary geology (igneous bodies, basement-detached faults, basin floor fans); primary fluid focussing and migration pathways and paleo-river drainage patterns, sediment composition and lithology.

A key requirement for informed marine-zone management is an understanding of the spatial patterns of marine biodiversity, often measured as species richness, total abundance or presence of key taxa. In the present study, we focussed on the diversity of benthic infauna and applied a predictive modelling approach to map biodiversity patterns for three study sites on the tropical Carnarvon shelf of Western Australia. A random forest decision tree model was used to generate spatial predictions of two measures of infaunal diversity, namely, species richness and total abundance. Results explained between 20% and 37% of the variance of each measure. The modelling process also identified potential physical surrogates for species richness and abundance, with sediment physical properties ranked as most important across the study region. Specifically, coarse-grained heterogeneous sediments were associated with higher infaunal species richness and total abundance. Seabed topographic properties were also important at the local scale. The study demonstrated the value of a surrogacy approach to the prediction of biodiversity patterns, particularly when the number of biological samples was limited. Such an approach may facilitate an understanding of ecosystem processes in the region and contribute to integrated marine management.

The Cenozoic carbonates of the Bounty-Talisman region can be divided into five major facies. From oldest to youngest, these are: Paleocene to Eocene basinal facies, Oligocene to Miocene slope-canyon facies, Oligocene to Miocene shelf facies, Oligocene to Miocene near-shore facies, and Pliocene-Quaternary shelf facies. This represents a shallowing-upwards cycle up to the late Miocene, followed by a significant transgression and a return to more open marine conditions in the Pliocene- Quaternary. The dominant geological processes controlling sonic velocity in the Cenozoic carbonates are physical compaction, burial calcite cementation, dolomitisation, and anhydrite/gypsum cementation. In the more open marine facies of the Cenozoic carbonates, compaction and burial calcite cementation have been the dominant geological processes that have controlled sonic velocity. Large-scale carbonate content variations associated with submarine canyon-fill sediments have also produced lateral sonic velocity variations. Dolomitisation and anhydrite cementation have produced localised high velocity zones within the near-shore facies of the carbonates.

A numerical basin modelling approach was used to investigate the hydrodynamics and development of overpressures in a Jurassic Prospect in the Greater Gorgon area of the Barrow Sub-basin. Abnormally large fluid pressures have been encountered by numerous exploratory wells in the Carnarvon Basin; however, the mechanisms responsible for overpressuring were uncertain. To better evaluate the risk of encountering overpressures while drilling Jurassic targets in the area, quantitative basin modelling was conducted. Groundwater flow, heat transfer, and hydrocarbon generation were simulated along two geologic cross-sections. Model results for the fluid pressure history of the Jurassic Prospect were constrained by hydrodynamic data from specific wells in the region. A series of modelling experiments was used to determine the relative significance of compaction disequilibrium, tectonic uplift, organic maturation and permeability on overpressure generation. Results indicate that compaction disequilibrium and the permeability of shale layers are the dominant controls on overpressures, while organic maturation does not contribute a significant amount to the pressure anomaly. Quantitative basin modelling applied to pressure prediction provides critical insight needed prior to drilling and well construction.

A combined molecular and morphological approach was used to revise the Australian spiny trapdoor spiders of the genus Blakistonia Hogg. Where possible, our molecular approach used sequence data from the COI barcoding gene, which were analysed using Bayesian, RAxML and neighbour-joining approaches. These molecular data were combined with morphology to describe and diagnose the genus, to redescribe the type (and only previously valid) species, B. aurea Hogg, 1902, and to diagnose, describe and map 19 new species: B. bassi sp. n., B. bella sp. n., B. birksi sp. n., B. carnarvon sp. n., B. emmottiorum sp. n., B. gemmelli sp. n., B. hortoni sp. n., B. mainae sp. n., B. maryae sp. n., B. newtoni sp. n., B. nullarborensis sp. n., B. olea sp. n., B. parva sp. n., B. pidax sp. n., B. plata sp. n., B. raveni sp. n., B. tariae sp. n., B. tunstilli sp. n., and B. wingellina sp. n. The genus Blakistonia is found to be distributed throughout the Australian arid and semi-arid zones, from the Wheatbelt region of Western Australia to central Queensland and western Victoria.

Thevenard Island area lies in the offshore Carnarvon Basin off the northwest coast of Western Australia. The Flacourt Formation of the Cretaceous Barrow Group sequence is the primary oil-producing reservoir. West Australian Petroleum Pty Limited (WAPET) as operator on behalf of its participants (Chevron, Texaco, Shell and Mobil) has been producing from this reservoir since 1989. It has widely been held that in this area the relatively thick, multi-darcy Barrow Group oil accumulations have had infinite aquifer pressure support with no regional draw-down effect.After the commencement of oil production from the Flacourt Formation, wireline pressure surveys in exploration and development wells have indicated anomalous pressure trends in the reservoir. Initially, the accuracy of pressure gauges and elevation measuring devices were questioned.Recent studies based on WAPET's production history in the region and re-analysis of wireline pressure data have shown that the Flacourt Formation does experience regional draw-down in aquifer pressure due to production. This paper demonstrates the existence of draw-down and how this information has aided in the evaluation of the Flacourt Formation and the overlying Mardie Greensand reservoirs.

BHP is a leading global resources company which comprises four main business groups: BHP Copper, BHP Minerals, BHP Steel and BHP Petroleum. BHP Petroleum (BHPP) global operations are divided into four Regions and Australia/Asia Region is responsible for exploration, production, field development and joint ventures in the Asia-Pacific region. In Australia, the Company's largest producing assets are its shares of the Gippsland oil and gas fields in Bass Strait and the North West Shelf project in Western Australia.BHPP operates three Floating Production, Storage and Offloading (FPSO) vessels-Jabiru Venture, Challis Venture and Skua Venture-in the Timor Sea and one FPSO, the Griffin Venture, in the Southern Carnarvon Basin. Stabilised oil is offloaded from all four FPSOs by means of a floating hose to a shuttle tanker. Gas from the Griffin Venture is compressed and transferred through a submarine pipeline to an onshore gas treatment plant.BHPP's Asian production comes from the Dai Hung oil field offshore Vietnam where BHPP is the operator and from Kutubu in Papua New Guinea.In Melbourne, BHPP operates a Methanol Research Plant and produced Australia's first commercial quantities of methanol in October 1994.BHPP is an extremely active offshore oil and gas explorer and has interests in a number of permits and blocks in the Australian-Indonesian Zone of Co-operation.This paper discusses BHPP's approach to safety management, both for its worldwide operations and specifically in Australia/Asia Region. It explains how BHPP's worldwide safety management model takes regional regulatory variations into account. It shows, specifically, how this has been done in Australia/Asia Region using what BHPP considers to be a best practice approach.The paper describes how BHPP Australia/Asia Region benchmarked its performance against other operators in Australia and the North Sea. It explains how the findings of the benchmarking study were used to plan the preparation of a safety management system (SMS). The structure of the SMS is described along with the legal requirements in Australia.The paper concludes that implementation of the SMS is progressing according to plan and points out that safety cases for the FPSOs have been submitted to the Regulators. Implementation of the SMS and the drive for world class safety standards is having a substantial effect and safety performance is improving. One measure of safety performance, the Lost Time Injury Frequency Rate (LTIFR) is down from around 15 at the end of 1994 to under 3 in December 1996.

The Exmouth Plateau is a deep-water plateau on the Australian continental margin underlain by 10–15 km of flat-lying, tilted and block-faulted Paleozoic–Mesozoic sedimentary rocks, which were deposited predominantly during periods of extension before continental break-up commenced in the middle Jurassic. The recent acquisition of the Mawson MC3D broadband seismic survey provides a modern, high-quality dataset located ~230 km to the north-west of Dampier, in the outboard Exmouth Plateau, in a relatively under-explored portion of the Northern Carnarvon Basin. The Late Triassic Mungaroo Formation is the primary reservoir target for the majority of the exploration in the Exmouth Plateau to date. A detailed investigation into the reservoir potential and prospectivity of the Mungaroo Formation is possible by utilising this modern dataset. The high-quality data presents a high-resolution view of the Rhaetian carbonate reef platforms and pinnacle reef complexes that are present within the Mawson survey footprint, revealing an under-explored play type within the region. The development of a detailed stratigraphic framework through the Late Triassic–Jurassic, combined with the use of attribute analyses and amplitude versus offset products can help de-risk identified prospects and highlight further prospectivity during the exploration process.

Hadson Carnarvon Pty Ltd (Hadson), on behalf of the Joint Venture Partners, operates permits EP342 and TP/9 located at the northern end of Exmouth gulf, to the east of Cape Range peninsula, Western Australia. The Exmouth region is known for the Ningaloo Reef, and for its diving and recreational fishing. The area also supports a large commercial prawn fishery. Many marine areas in the Exmouth region are regarded as being environmentally sensitive with several areas of conservation value.The partners were committed to drilling two wells in EP342 and TP/9 in 1993 as part of the obligations under the permits. Public mistrust of, and an unfamiliarity with, the oil and gas industry gave the Exmouth community the perception that the EP342 drilling program would have a detrimental impact on the sensitive marine resources of the region and, hence, to the growing tourism industry in the region.Hadson developed a management strategy which involved an extensive local community education and consultation program. Activities for this program included presentations to various community and special interest groups and a two-day public exhibition in Exmouth. The management strategy also included commitment to statutory and voluntary environmental guidelines, and an impact assessment study.Hadson's communication program was successful on a local level: by the time drilling commenced, active opposition to the drilling program had diminished significantly. This drilling program showed the importance of involving the public in the plans of the company, of putting a 'face' to the company and of communicating environmental risk in a trustworthy manner.The State Government announced in July 1994 that petroleum exploration within Ningaloo Marine Park would not be permitted. This decision was not based on scientific evidence, but political strategy and a perception that in the Exmouth and wider community there was an innate 'fear' regarding the impact of the petroleum industry.

Available data for 2018 indicates that exploration activity is on the rise in Australia, compared to 2017, and this represents a second year of growth in exploration activity in Australia. There has been an increase in area under licence by 92 000 km2, reversing the downward trend in area under licence that commenced in 2014. Since 2016, exploratory drilling within Australia has seen a continued upward trend in both the number of wells drilled and the percentage of total worldwide. Onshore, 77 conventional exploration and appraisal wells were spudded during the year. Offshore, exploration and appraisal drilling matched that seen in 2017, with five new wells spudded: two in the Roebuck Basin, two in the Gippsland Basin and one in the North Carnarvon Basin. Almost 1500 km of 2D seismic and over 10 000 km2 of 3D seismic were acquired within Australia during 2018, accounting for 2.4% and 3.9% of global acquisition, respectively. This represents an increase in the amount of both 2D and 3D seismic acquired in Australia compared with 2017. Once the 2017 Offshore Petroleum Acreage Release was finalised, seven new offshore exploration permits were awarded as a result. A total of 12 bids were received for round one of the 2018 Offshore Petroleum Exploration Release, demonstrating an increase in momentum for offshore exploration in Australia. The permits are in Commonwealth waters off Western Australia, Victoria and the Ashmore and Cartier islands. In June 2018, the Queensland Government announced the release of 11 areas for petroleum exploration acreage in onshore Queensland, with tenders closing in February/March 2019; a further 11 areas will be released in early 2019. The acreage is a mix of coal seam gas and conventional oil and gas. Victoria released five areas in the offshore Otway Basin within State waters. In the Northern Territory, the moratorium on fracking was lifted in April, clearing the way for exploration to recommence in the 2019 dry season. With the increase in exploration has come an increase in success, with total reserves discovered within Australia during 2018 at just under 400 million barrels of oil equivalent, representing a significant increase from 2017. In 2018, onshore drilling resulted in 18 new discoveries, while offshore, two new discoveries were made. The most notable exploration success of 2018 was Dorado-1 drilled in March by Quadrant and Carnarvon Petroleum in the underexplored Bedout Sub-basin. Dorado is the largest oil discovery in Australia of 100 million barrels, or over, since 1996 and has the potential to reinvigorate exploration in the region.

2009 saw an overall decrease from high activity from 2008, levelling off in the December quarter as the economy stabilised. Unsurprisingly, most activity was in offshore Western Australia and on coal seam methane (CSM) in Queensland. Highlights include: good results in the Carnarvon and Browse basins for Western Australian operators, interest in Karoon and Conoco-Phillips’ enigmatic Poseidon project, over 180 CSM exploration wells in Queenslandd, and a relatively busy year for Tasmania. Western Australian seismic acquisition approached 10,000 km of 2D and 25,000 km2 of 3D for 38* wells and success rate around 50%. South Australia saw the highest conventional onshore drilling and seismic activity, with good results for 17 wells, while other states saw low activity in this sector. Victoria saw one offshore exploration well and no seismic. Tasmania also saw no new seismic, but saw four exploration wells and encouragement at Rockhopper–1. CSM is picking up in South Australia, and New South Wales saw continued high CSM activity in a historically low-activity region. High success rates suggest two trends: explorers finding value in 3D seismic, and a ‘flight to quality’ as operating costs and poorer access to capital reinforce risk aversion among operators. Elsewhere, geothermal energy helped small cap investors satisfy their appetite for risk outside of the petroleum industry, and results will be watched with great interest. *Numbers are from early public and departmental statistics and may be revised.

The southern Merlinleigh Sub-basin is a frontier area for petroleum exploration within the onshore Southern Carnarvon Basin, with limited seismic coverage and only two deep exploration wells. High resolution aeromag- netic and semi-detailed gravity data acquired in 1995 provide relatively low cost structural inf ormation"comple- mentary to the regional seismic coverage.Two-dimensional seismic data can be mapped with confidence if the lines are closely spaced. By identifying lineaments on potential-field images, orientations for structures within the sedimentary succession, and at basement or intra-basement levels, can assist in the interpretation of faults and structures in areas of limited seismic coverage, and to extrapolate them outside areas of seismic control. Consequently, by integrating seismic and potential-field data, a more rigorous interpretation of the structural geometry can be achieved and thereby assists in reconstructing the evolution of a sedimentary basin.The aeromagnetic data provided only limited information about the structure of the Merlinleigh Sub-basin because magnetic anomalies appear to be dominated either by near-surface or deep intra-basement sources. In contrast, the gravity data provide a more reliable definition of the structure at basement level and, to a lesser extent, within the sedimentary sequence.Seismic, gravity and magnetic data show that the region is a large north-trending Late Carboniferous to Permian depocentre and can be sub-divided into two main troughs east of the Wandagee and Kennedy Range Faults. These are en-echelon fault systems with syn- depositional growth during the main period of rifting in the Late Carboniferous to Early Permian.

Numerous Miocene reefs and related carbonate build-ups have been identified in the Rowley Shoals region of the central North West Shelf, offshore Western Australia. The reefs form part of an extensive Miocene reef tract over 1,600 km long, which extended northward into the Browse and Bonaparte basins and southward to North West Cape in the Carnarvon Basin—comparable in length to the modern Great Barrier Reef. Growth of the vast majority of these Miocene reefs failed to keep pace with relative sea-level changes in the latest Miocene, whereas reef growth continued on the central North West Shelf to form the three present-day atolls of the Rowley Shoals: Mermaid, Clerke and Imperieuse reefs. In the Rowley Shoals region, scattered small build-ups and local reef complexes were first established in the Early Miocene, but these build-ups were subsequently terminated at a major Mid Miocene sequence boundary. Widespread buildups and atoll reefs were re-established in the Middle Miocene, and the internal stacking geometries of the reefs appear to relate to distinct growth phases that are correlated with eustatic sea-level fluctuations. These geometries include: a basal aggradational buildup of early Middle Miocene age; a strongly progradational growth phase in the late Middle to early Late Miocene that constructed large reef atolls with infilling lagoon deposits; and a back-stepped aggradational growth phase that formed smaller reef caps in the early–latest Late Miocene. Growth of the majority of the reefs ceased at a major sea-level fall in the Late Miocene (Messinian), and only the reefs of the present-day Rowley Shoals (Mermaid, Clerke and Imperieuse reefs, as well as a drowned shoal to the southwest of Imperieuse Reef) continued to grow after this event. Growth of the Rowley Shoals reefs continued to keep pace with Pliocene-Recent sea-level changes, whereas the surrounding shelf subsided to depths of 230–440 m. We conclude that initial reef growth in the Rowley Shoals region was controlled by transpressional reactivation and structuring of the Mermaid Fault Zone during the early stage of collision between the Australian and Eurasian plates. During this structural reactivation, seabed fault scarps and topographic highs likely provided ideal sites for the initiation of reef growth. The subsequent growth and selective demise of the reefs was controlled by the interplay of eustatic sea-level variations and differential subsidence resulting from continued structural reactivation of the Mermaid Fault Zone. In contrast to models proposed in other regions, there is no direct evidence that active or palaeo hydrocarbon seepage triggered or controlled growth of the Rowley Shoals reefs or their buried Miocene predecessors.

The Australian Government formally releases new offshore exploration areas at the annual APPEA conference. In 2010, thirty-one areas in five offshore basins are being released for work program bidding. Closing dates for bid submissions are either six or twelve months after the release date—i.e. 11 November 2010 and 12 May 2011—depending on the exploration status in these areas and on data availability. The 2010 release areas are located in Commonwealth waters offshore Northern Territory, Western Australia and South Australia, comprising intensively explored areas close to existing production as well as new frontiers. The Westralian Superbasin along the North West Shelf continues to feature prominently, and is complimented by a new frontier area in offshore SW Australia (Mentelle Basin), as well as two areas in the Ceduna/Duntroon sub-basins in the eastern part of the Bight Basin. The Bonaparte Basin is represented by three areas in the Petrel Sub-basin and two areas in the Vulcan Sub-basin. Further southwest, four large areas are being released in the outer Roebuck Basin—a significantly under-explored region. This year, the Carnarvon Basin provides 16 release areas of which three are located in the Beagle Sub-basin, five in the Dampier Sub-basin, five in the Barrow Sub-basin, three on the Exmouth Plateau and three in the Exmouth Sub-basin. The largest singular release area covers much of the Mentelle Basin in offshore SW Australia, and two areas are available in the Ceduna and Duntroon sub-basins as part of South Australia’s easternmost section of the Bight Basin. The 2010 Offshore Acreage Release offers a wide variety of block sizes in shallow as well as deep water environments. Area selection has been undertaken in consultation with industry, the States and the Northern Territory. As part of Geoscience Australia’s Offshore Energy Security Program, new data has been acquired in offshore frontier regions parts of which are being published on the Mentelle Basin (Borissova et al, this volume).

AbstractAn association of 100 teeth and 15 vertebrae from a large, lamniform shark, is described from the uppermost part of the Gearle Siltstone in the Giralia Anticline, Southern Carnarvon Basin, Western Australia. The material represents a new genus and species: Cardabiodon ricki. The taxon is referred to the new family Cardabiodontidae on the basis of its dental formula and uniquely oversized lower lateroposterior teeth. Other characteristic features include a strong dignathic heterodonty and the presence of four anterior and approximately 14 lateroposterior toothfiles in both the upper and lower jaw. The size of the recovered vertebral centra indicates that the shark measured at least 5 m in total length. The species had a wide but possibly patchy distribution with additional occurrences in England and Kazakstan, where it is present in strata of Cenomanian age. Cardabiodon shares several key dental characters with Parotodus, known from Oligocene–Pliocene deposits. The latter taxon was previously grouped with the ‘mega-toothed’ sharks of the genera Otodus and Carcharocles, but is here reassigned to the Cardabiodontidae.The nominal species Cretalamna woodwardi from the middle or late Cenomanian of southern England, is designated as the type species of the new genus Dwardius. The coeval nominal species Pseudoisurus tomosus from the Saratov region in Russia, is based on material that almost certainly includes C. ricki and/or D. woodwardi. Designation of a lectotype for P. tomosus and its proper documentation would probably allow either C. ricki or D. woodwardi to be synonomised with the older name P. tomosus. There is, however, a strong possibility that the syntypes of P. tomosus are lost. Until they are found, redescribed and compared carefully with the type material of C. ricki and D. woodwardi, P. tomosus is a name of doubtful application and therefore referred to as a women dubium

Esso's recent drilling program in the Merlinleigh Sub-basin, onshore Carnarvon Basin, represents the culmination of the first phase of concerted exploration activity in the area since the WAPET era of the 1960s. The region is unusual among Australian petroleum provinces in having excellent exposures of reservoir, source and seal rocks of Palaeozoic age. While both Esso wells (Burna 1 and Gascoyne 1) failed to encounter hydrocarbons in the primary Wooramel Group play, encouraging potential still exists. The reservoir in the Wooramel Group play is the Early Permian Moogooloo Sandstone, a fluviodeltaic to nearshore sheet-sand facies with porosities to 23 per cent and permeabilities in excess of 100 millidarcys. Likely hydrocarbon sources are siltstones in the overlying Byro Group, with total organic carbon contents averaging 3 per cent, and calcilutites in the subjacent Callytharra Formation with similar organic content. Locally, the Jimba Jimba Calcarenite Member (Billidee Formation) and the Cordalia Sandstone also provide rich source units. The least certain aspects of the Early Permian play are fault and top seal, and reservoir quality at depth. Notwithstanding the relatively shallow depths to source strata in the area, vitrinite reflectance analyses from drill cores indicate that maturation is attained as shallow as 900 m on the folded and faulted western margin of the sub-basin, and at an approximate depth of 1200 m in the depocentre beneath the Kennedy Range. This can be related to high regional heat flow, and to erosion of some 1500-2000 m of sediments prior to the regional Early Cretaceous transgression.Older plays which have been identified in the area remain to be adequately evaluated. Potential reservoir sands are present in the Silurian Tumblagooda Sandstone, the Middle and Late Devonian Nannyarra and Munabia Sandstones, and the Early Carboniferous Williambury Formation. Possible source rocks include carbonates of Middle Devonian and Early Carboniferous age. One of the objects of current research has been to locate areas where seal, provided by the glacigene Lyons Formation of Late Carboniferous-Early Permian age, is sufficiently thin to permit economic drilling.

The Australian Government formally releases new offshore exploration areas at the annual APPEA conference. In 2011, 29 areas in eight offshore basins are being released for work program bidding. Closing dates for bid submissions are either six or 12 months after the release date (i.e. 13 October 2011 and 12 April 2012)–this depends on the exploration status in these areas and on data availability. The 2011 Release is the largest since the year 2000 with all 29 areas located in Commonwealth waters offshore NT, WA, Victoria and Tasmania, covering about 200,000 km2. The producing hydrocarbon provinces of the Carnarvon, Otway and Gippsland basins are represented by gazettal blocks that are located close to existing infrastructure and are supported by extensive open file data-sets. Other areas that are close to known oil and gas discoveries lie in the Caswell Sub-basin (eastern Browse Basin) and on the Ashmore Platform (northwestern Bonaparte Basin). A particular aspect of the 2011 release is provided by 13 areas in under-explored regions offshore NT and WA–all of which range from 100–280 graticular blocks in size. These areas, located in the Money Shoal, outer Browse, Roebuck, northeastern Carnarvon, Southern Carnarvon and North Perth basins, offer new opportunities for data-acquisition and regional exploration. The release of three large areas in the Southern Carnarvon and North Perth basins is supported by new data acquired and interpreted by Geoscience Australia as part of the Offshore Energy Security Program, which selected results are being presented at this year’s conference.

In Western Australian basins, subsurface drill-hole data, primarily from petroleum exploration, allows the identification of regions of high temperature at depth that may be potential geothermal resources. The extent and economic viability of such resources remain poorly known and require further study. Observed temperatures at depths up to 4.5 km reach 150°C in parts of the Canning, Carnarvon and Perth basins, indicating low-enthalpy resources related to regional heat flow. The greatest potential for hydrothermal resources is in the Perth Basin where subsurface temperatures of 65–85°C are reached at 2–3.5 km depth. Heat-flow modelling of 170 Perth Basin wells shows a range of 30–140 mW/m2, with the highest surface heat-flow values in the northern part of the basin. The median value of 76.5 mW/m2 for this basin exceeds the average reported for the Australian continent—64.5 mW/m2. Potential hot rocks resources are present in parts of the Canning, Carnarvon and Perth basins where the depth to 200°C is less than 5 km. Knowledge of high subhorizontal stress conditions that can enhance geothermal water flow from engineered reservoirs are based on data mostly from petroleum wells in the Perth Basin. A systematic quantitative assessment of geological, hydrogeological, geophysical, stress orientation and geochemical conditions is required to further delineate and prove these resources. Progressive compilation, validation and interpretation of subsurface data from more than 800 wells is underway, and includes temperature logs of 47 shallow water bores and 30 new thermal conductivity measurements of Perth Basin wells. Data compilation from 580 wells in the Canning, Carnarvon and Perth basins is complete. To date the greatest number of wells indicating high geothermal gradients and temperatures are in the Carnarvon Basin.

Since the commencement of the major developments on the North West Shelf, the offshore resource industry, during both its construction and operational phases, has faced considerable logistical impediments to cost-effective solutions for the offshore supply chain. These impediments have included distance, scant resources, lack of infrastructure both on and offshore and lack of critical mass.Throughout the world, offshore projects have greatly benefitted from the availability of integrated services to cater for the transport of equipment from the point of manufacture or distribution to the offshore location.Within the Australian context the privately controlled Esso Barry Beach and Dampier Woodside facilities are examples of integrated services, but both differ considerably from a public multi-user facility. The model used in the Timor Sea of one vessel or vessels for the use of several operators is another example.The NorthWest Shelf has now reached the critical mass and it became apparent several years ago that the area needed an integrated supply base available to multiple operators. It would need to include a heavy loadout wharf, laydown areas, slipway and engineering facilities and office space to service forthcoming projects, as well as planning and cooperation amongst all players to maximise efficiency and use of scant resources as drivers for economic benefits to offshore operators in the region.Furthermore the fallout from the events of 11 September 2001 and continuing threats of terrorism has meant the security of marine assets has become an important part of each operator’s everyday life. The introduction of new legislation relating to this security issue is planned for mid 2004.In 2000 and 2001 Mermaid Marine Australia Limited undertook a major expansion of its Dampier supply base, and established a world-class facility to meet the growing demands of the region.This complex has for the first time provided the northwest of Australia, particularly the North West Shelf, Carnarvon Basin and the onshore developments on the Burrup Peninsula, with a facility for offloading and loadout of heavy shipments and fabrication and slipway facilities, coupled with the advantages of a large supply base. This facility can also be expanded to meet growth and the emerging requirements related to security.This paper describes the drivers for change commencing with the earliest supply chains and following through to the integrated service now availabe. These drivers meet the requirements of the offshore operators in the region as well as showing the benefits anticipated from this integrated service. The paper also outlines in detail the requirements of the International Maritime Organisation for worldwide changes to port and offshore security.

AbstractMosasaurs are rare in Australia with fragmentary specimens known only from the Cenomanian-lower Turonian Molecap Greensand (Perth Basin), Campanian - lower Maastrichtian Korojon Calcarenite (Carnarvon Basin), and upper Maastrichtian Miria Formation (Carnarvon Basin), Western Australia. These units were laid down during a near-continuous marine inundation of the western margin of the Australian landmass (which followed separation from India in the Valanginian and genesis of the Indian Ocean) in the Early-Late Cretaceous. The Australian mosasaur record incorporates evidence of derived mosasaurids (mainly plioplatecarpines); however, as yet no specimen can be conclusively diagnosed to genus or species level. The fragmentary nature of the remains provides little basis for direct palaeobiogeographic comparisons. However, correlation with existing data on associated vertebrates, macroinvertebrates and microfossils suggests that the Western Australian mosasaur fauna might have been transitional in nature (particularly following palaeobiogeographic separation of the northern and southern Indian Oceans during the mid-Campanian), potentially sharing elements with both northern Tethyan and austral high-latitude regions.

2012 was a pivotal year for Australian petroleum development and production, during a dynamic time in our region, and globally. Australian activity headlines are LNG, the continuing pace and scale of the development of major projects, and record national petroleum production. LNG development in Australia is proceeding apace, with seven sanctioned projects under construction in WA and Queensland. The scale of the major projects underway is being felt with competition for skills, materials and services driving cost inflationary pressures and, coupled with other factors—such as an historically high Australian dollar—has resulted in several announced budget increases and schedule slippages. In addition, the regulatory framework is evolving, as regulators adapt to new industry trends and technologies. Proponents of future developments and expansions will be seeking to sanction in a tougher, but potentially better-informed development environment. Overall, national hydrocarbon production increased to a record high in 2012, attributable to a number of factors, but not least of which was the commissioning and successful start of commercial production of the Woodside-operated Pluto LNG development from the Pluto and Xena fields in the Carnarvon basin. Pluto was the first commissioned project since 2006, and may be viewed as the first of a number of developments that will be coming on-stream in the next few years, and will elevate Australia’s position in the ranking of world LNG production. Adding production from Pluto has allowed Woodside to take the lead position as the highest petroleum producer from BHP Billiton during 2012. Activity is not limited to LNG. Other highlights for 2012 included the opening of the Devil Creek project on the North West Shelf, WA’s third domestic gas hub, with the potential to supply around 20% of the state’s needs. Cost increase and schedule delay is not limited to LNG either, with Yolla mid-life enhancement and the Kipper offshore development facing cost and schedule pressure. In the broader global sphere, the highlight of 2012 is the extraordinary rise of unconventional oil in the US to the point of speculation about future US self-sufficiency. This parallels the rise of US unconventional gas in recent years, with gas supplies exceeding existing domestic demand and driving down the previously high domestic prices. Presently, only one US LNG project is approved for export; however, with an ongoing policy debate in the US about significant gas export verses retention to spur domestic growth, and favourable location of potential US access to the Asian market, the outcome is important for future competition to Australia’s cost-challenged LNG industry. Among this the announcement by Santos of the connection of the first shale gas well in Australia to sales delivery—albeit as an appraisal well—is a notable occurrence as a potential forerunner of shale gas production in Australia.

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 202246, “Wheatstone: What We Have Learned in Early Production Life,” by John Pescod, SPE, Paul Connell, SPE, and Zhi Xia, Chevron, et al., prepared for the 2020 SPE Asia Pacific Oil and Gas Conference and Exhibition, originally scheduled to be held in Perth, Australia, 20–22 October. The paper has not been peer reviewed. Wheatstone and Iago gas fields, part of the larger Wheatstone project, commenced production in June 2017. The foundation subsea system includes nine Wheatstone and Iago development wells tied back to a central Wheatstone platform (WP) for processing. Hydrocarbons then flow through an export pipeline to an onshore processing facility that includes two liquefied-natural-gas (LNG) trains and a domestic gas facility. The complete paper highlights some of the key learnings in well and reservoir surveillance analysis and optimization (SA&O) developed using data from early production. Asset Overview Chevron Australia’s Wheatstone project is in the North West Shelf region offshore Australia (Fig. 1). Two gas fields, Wheatstone and Iago (along with a field operated by a different company), currently tie into the WP in the Northern Carnarvon Basin. These two gas fields are in water depths between 150 and 400 m. The platform processes gas and condensate through dehydration and compression facilities before export by a 220-km, 44-in., trunkline to two 4.45-million-tonnes/year LNG trains and a 200 tera-joule/day domestic gas plant. A Wheatstone/Iago subsea system consisting of two main corridors delivers production from north and south of the Wheatstone and Iago fields to the WP. Currently, the subsea system consists of nine subsea foundation development wells, three subsea production manifolds, two subsea 24-in. production flowlines, and two subsea 14-in. utility lines. The nine foundation development wells feed the subsea manifolds at rates of up to 250 MMscf/D. These wells have openhole gravel-pack completions for active sand control and permanent downhole gauges situated approximately 1000-m true vertical depth above the top porosity of multi-Darcy reservoir intervals for pressure and temperature monitoring. All wells deviate between 45 and 60° through the reservoir with stepout lengths of up to 2.5 km. The two subsea 24-in. production flowlines carry production fluids from the subsea manifolds to two separation trains on the WP. Each platform inlet production separator can handle up to 800 MMscf/D. The two 14-in. utility flowlines installed to the subsea manifolds allow routing of a single well to the platform multiuse header, which can direct flow into the multiuse separator (MUS) or other production separators at a rate of 250 MMscf/D.

Each year the Australian Government releases new offshore opportunities for petroleum exploration. Thirty-five new exploration areas located across five of Australia’s offshore sedimentary basins are offered in the 2008 Release. All the areas are available through a work program bidding system with closing dates for bids at six and 12 months from the date of release. Acreage in the first round closes on 9 October 2008 and includes the more explored areas. The second closing round on 9 April 2009 comprises acreage located in less well explored and frontier regions. The 2008 exploration areas are in Commonwealth waters offshore of Western Australia and the Northern Territory, and in the Territory of the Ashmore and Cartier Islands adjacent area. The 2008 Release focusses on the North West Shelf, as well as offering two new exploration areas in the Vlaming Sub-basin in the offshore Perth Basin. Seven of the new release areas are located in Australia’s major hydrocarbon producing province, the Carnarvon Basin. They include a shallow water area in the western Barrow Sub-basin and another on the Rankin Platform, three areas in deeper water in the Exmouth Sub-basin and two on the deepwater Exmouth Plateau. Six areas are available for bidding in the Browse Basin and another five in the Bedout Sub-basin of the Roebuck Basin. In the Bonaparte Basin, the 15 Release areas are located in shallow water and represent a range of geological settings, including the Vulcan and Petrel sub-basins, Ashmore Platform and Londonderry High. The 2008 Offshore Petroleum Exploration Release of 35 areas in five basins covers a wide range in size, water depth and exploration maturity to provide investment opportunities suited to both small and large explorers. The Release areas are selected from nominations from industry, the States and Territory, and Geoscience Australia. The focus of the 2008 Release is on the North West Shelf where there is strong industry interest in the producing Carnarvon and Bonaparte basins and in the Browse Basin, the home of super-giant gas fields under active consideration for development. Also included in the 2008 Release is the Bedout Sub-basin, in the Roebuck Basin, located on the central North West Shelf, between the hotly contested Carnarvon and Browse basins. In addition, the Release show-cases the southern Vlaming Sub-basin, Perth Basin, where recent studies by Geoscience Australia provide a new understanding of petroleum potential (Nicholson et al, this volume).

Sequence biostratigraphy is a relatively new discipline that has rapidly expanded in parallel with the development of sequence stratigraphy. Sequence bios- tratigraphic concepts have resulted in significant improvements in our ability to calibrate biozones, correlate and determine ages of sedimentary units, and to estimate environments of deposition. Significant advances in the development of integrated biostratigraphic methods and knowledge during the past 20 years are now being rapidly integrated into the physical framework provided by depositional sequences. Sequence stratigraphy provides a physical framework consisting of a predictable hierarchy of correlation surfaces, ranging from sequence boundaries to parasequence boundaries, within which biostratigraphic observations may be placed. These correlation surfaces define chronostratigraphic units with varying degrees of lateral extent that can be used to assess, using time-distance grids, the relative position of biozone 'tops' or 'bases'. They also provide a physical link between the open-ocean planktonic microfossil chronozones and chronozones developed in paralic and non-marine strata. In addition, the delineation of large, apparently sudden, water depth changes across downlap surfaces, associated with condensed sections, has resulted in more accurate and precise paleobathymetric estimation in exploration wells. Recognition and biostratigraphic 'fingerprinting' of major water depth changes are essential for correlation through intensely faulted areas.The rate of return from biostratigraphic and geochemi- cal sampling is generally poor primarily because of the lack of emphasis on the importance of developing and maintaining well planned sampling strategies and programs throughout an exploration drilling program. The design of biostratigraphic and geochemical sampling strategies has been improved by sequence stratigraphic concepts. Biostratigraphic sample quality (high) is inversely proportional to sedimentation rate (low). Sequence biostratigraphy provides a consistent, predictable, method of recognising low sedimentation rate units in the subsurface using a variety of tools, ranging from seismic to well log facies analysis.Some of the basic principles of sequence biostratigraphy are illustrated using an example from the Carnarvon Basin. The Barremian A. cinctum andM. australis dinocyst Acme and Oppel zones respectively, appear to be strongly associated with distinct environments. Consequently, it is difficult to calibrate them to the AGSO timescale and to use them regionally as reliable zones to subdivide the Barremian. Abundant numbers of A. cinctum appear to be restricted to specific regions of the Carnarvon dominated by shallower marine conditions and associated with the infilling of major incised river systems. Further biostratigraphic subdivisions within the Early Cretaceous and specifically the M. australis - A. cinctum interval are warranted, especially in light of the number of plays and prospects defined and discoveries made within this interval of the Carnarvon Basin. More detailed biostratigraphic work coupled with regional sequence stratigraphy and a more focussed sampling strategy should produce a high quality age-model for this prospective interval that had not received significant attention until recently.

Record-high oil prices along with on-going development of infrastructure, increasing domestic demand and international LNG sales continued to drive significant investment in exploration in onshore and offshore Australia during 2007. These trends are reflected nationally by strong uptake of acreage and continued high levels of drilling activity and seismic acquisition. Overall, drilling and discovery trends were similar to 2006 which showed significant exploration activity focussed on proven hydrocarbon basins (Carnarvon, Browse, Perth and Cooper basins). Most petroleum discoveries made in 2007 were located within 10 to 15 km of existing fields. In terms of number of exploration wells, the offshore Carnarvon continued to dominate with over 20 new field wildcats drilled. Discoveries include a major deep-water gas find for BHP-Billiton at Thebe-1 on the outer Exmouth Plateau, Apache’s gas finds at Brunello–1, Julimar–1 and Julimar East–1, oil for Santos at Fletcher–1 and gas at Lady Nora–1 for Woodside. The Browse Basin saw a significant increase in drilling activity with some success. Exploration in the offshore southwest margin received a major boost with a series of shallow-water discoveries for ROC Oil in the Perth Basin with gas at Frankland–1 395and Perseverance–1 and gas and oil at Dunsborough–1. Onshore, the Cooper/Eromanga basins continued to experience the highest level of drilling activity and seismic acquisition. This activity resulted in numerous small to moderate oil discoveries for Santos, Beach Petroleum, Eagle Bay Resources, Stuart Petroleum and Victoria Petroleum. There were a few notable exceptions to near-field exploration in 2007 with several wildcats drilled in frontier regions including PetroHunter Energy and Sweetpea Petroleum’s Shanendoah–1 in the Georgina/Betaloo basins, Austin’s Gravestock–1 in the onshore Stansbury Basin and the onshore drilling campaign by ARC Energy in the Canning Basin. In Queensland, CSM exploration and discovery continued to experience strong positive growth underpinned by delivery to local markets.

Members of the genus Diporiphora are slender perching agamid lizards from Australasia, with a conservative morphologyand some outstanding taxonomic issues. Here we assess morphological variation in the morphologically similar D. pin-dan, D. valens, and D. winneckei from the western deserts of Australia. A reassessment of morphological differences thatincluded the presence or absence of a gular fold, revealed D. pindan to be much more widely distributed than previouslythought, occurring as far south as the northern Pilbara and east to the Tanami Desert. Examination of D. valens specimensrevealed a north-south split within the Pilbara, with specimens conspecific with the types from the Hamersley Range inthe southern Pilbara, whereas recently collected specimens from the Chichester and Roebourne regions in the northernPilbara differ morphologically, and are described as a new species. Examination of the type of D. winneckei and topotypicmaterial indicates that populations referable to this species are confined to the eastern arid zone. The isolated far westernpopulation of ‘D. winneckei’ from the Carnarvon Basin differs in morphology from the eastern arid zone D. winneckei andis described as a new species. The western arid zone ‘D. winneckei’ is also morphologically distinctive from the easternarid zone D. winneckei and is described as a new species. We also redescribe D. pindan, D. valens, and D. winneckei, and return Caimanops amphiboluroides to Diporiphora based on the results of previous genetic studies.

The Australian Government formally releases new offshore exploration areas at the annual APPEA conference. The previous two releases were characterised by several large, gazetted areas in underexplored regions, a trend that is maintained this year with several frontier areas comprising more than 100 graticular blocks on offer. The recent uptake of new exploration permits in the Bight Basin, the offshore North Perth Basin, and the Roebuck Basin indicates a continuing strong industry interest in offshore frontier exploration. A total of 31 areas in 13 geological provinces are formally released in 2013, and work program bids are invited for two rounds closing on 21 November 2013, and 22 May 2014. Area gazettal was, again, well supported by industry nominations. The areas on offer are represented by an even mix of shallow and deepwater areas, as well as by areas close and distant to previous discoveries and producing fields. The Northern Carnarvon, Browse, and Bonaparte basins dominate new exploration opportunities in the 2013 release, while only four areas were gazetted in the North Perth, Otway, and Gippsland basins. These also deserve attention as they have exploration potential in underexplored parts of the basins and offer opportunities to test new play concepts. Data coverage varies from being excellent in more mature areas to sparse in underexplored areas such as the North Perth Basin. The Australian Government continues to assist offshore exploration activities by providing free access to a wealth of open-file geological and geophysical data.

The WestraliaSPAN 2D regional program extends across all basins of Australia’s North West Shelf (Carnarvon/Roebuck/Browse/Bonaparte basins) and Arafura regions. The survey is designed with long offset and record length (18 sec) acquisition parameters to image the important deep crustal and sub crustal architecture and depositional systems across this complex margin. The regional program provides unique, state-of-the-art depth imaging of deep-basement rift structures of the Westralian Superbasin, as well as the lower crust and Moho. The survey has multiple transects which cross the transition from continental to oceanic crust, that provide insight into the distribution of volcanics and a possible hyper-extended rift margin. An integrated geological and geophysical interpretation encompasses available well, seismic and potential field data. Gravity models were developed to aid in depth conversion and the structural interpretation of the deep crust and Moho. A comprehensive model of basin formation provides the context for regional correlation of tectonostratigraphic packages throughout these linked basin systems, highlighting pre-Jurassic rift basins and their structural controls. While the North West Shelf, Browse and Bonaparte basins are proven and established hydrocarbon provinces, a future step-change in exploration concepts involves an integrated, margin-scale understanding of these basin systems and their potential resources. Collectively, the new dataset and interpretation will aid explorers in understanding the nature and distribution of key petroleum systems elements (reservoir/source/seal) and processes (heatflow, timing of source maturity, expulsion, migration and entrapment).

A pilot study to determine if zircons present in reservoir facies of the North West Shelf can be used to identify provenance and sediment transport pathways has analysed samples from three wells: Guardian–1 and Hijinx–1 (Carnarvon Basin), and Burnside–1 (Browse Basin). Operating companies Chevron, Santos and Hess collected 3–5 kg of cuttings from sandstone bodies intersected in the three wells. Samples were sent to Geoscience Australia for zircon separation and analysis at the Geochronology Laboratory on a sensitive high-resolution ion microprobe (SHRIMP). To provide a statistically meaningful representation of ages in each sample, 70–80 grains were randomly selected for analysis. During the past 20 years, Geoscience Australia and the state geological surveys of WA, NT, Queensland and SA, together with the ANU, UWA and Curtin University, have analysed zircons found in igneous and sedimentary rocks that outcrop in WA and central Australia. This analysis has been done to determine the ages of emplacement, extrusion or maximum depositional ages. This dataset permits the ages of potential onshore provenance areas to be differentiated; hence, correlations can be made between zircons contained within the transported sands and their potential source regions from onshore Australia. In this extended abstract, the spectrum of ages in each sample will be shown, and potential provenance and sediment transport pathways will be discussed. The abstract concludes with the outline of a 2–3 year project to obtain a dataset that will provide a regional stratigraphic and spatial coverage of the North West Shelf for provenance studies.

Amongst diverse and abundant fossil proteaceous pollen in southeastern Australian Late Cretaceous (Campanian–Maastrichtian) sediments are forms identical with pollen of extant taxa within subfamilies Proteoideae, Persoonioideae, Carnarvonioideae, and Grevilleoideae. Taxa identified now have disparate geographic ranges within Australasia. Sclerophyllous Adenanthos and Stirlingia (Proteoideae) are restricted to the southern Australian Mediterranean climatic region; Persoonia (Persoonioideae) ranges into higher rainfall areas of eastern and northern Australia. Grevillea exul – Grevillea robusta and Telopea (Grevilleoideae) and Carnarvonia (Carnarvonioideae) occur in or fringe rain forests in eastern Australasia, as do other members (Macadamia, Gevuina–Hicksbeachia, Knightia, and Beauprea) reported previously. Pollen evidence thereby confirms evolution of both rain forest and sclerophyll members by the Campanian–Maastrichtian. Turnover of proteaceous pollen taxa near the Cretaceous–Tertiary boundary may reflect contemporaneous modifications to the proteaceous communities. Associated with the Late Cretaceous Proteaceae were diverse conifers (Microcachrys, Lagarostrobus, Podocarpus, Dacrydium, Dacrycarpus, and Araucariaceae), Nothofagus, Ilex, Gunnera, Ascarina, Winteraceae, Trimeniaceae, and probable Epacridaceae. The vegetation, which fringed a narrow estuary separating Antarctica from southern Australia, implies a mosaic of rain forest and sclerophyll communities but has no modern analogue. Key words: Proteaceae, Late Cretaceous, Australia, Antarctica.

The Australian Government formally releases new offshore exploration areas at the annual APPEA conference. This year, 31 areas plus two special areas in five offshore basins are being released for work program bidding. Closing dates for bid submissions are either six or twelve months after the release date (i.e. 3 December 2009 and 29 April 2010), depending on the exploration status in these areas is and on data availability. The 2009 release areas are located in Commonwealth waters offshore Northern Territory, Western Australia, South Australia and Victoria, comprising intensively explored areas close to existing production as well as new frontiers. As usual, the North West Shelf features very prominently and is complimented by new areas along the southern margin, including frontier exploration areas in the Ceduna Sub-basin (Bight Basin) and the Otway Basin. The Bonaparte Basin is represented by one release area in the Malita Graben, while five areas are available in the Southern Browse Basin in an under-explored area of the basin. A total of 14 areas are being released in the Carnarvon Basin, with eight areas located in the Dampier Sub-basin, three small blocks in the Rankin Platform and three large blocks on the Northern Exmouth Plateau (these are considered a deep water frontier). In the south, six large areas are on offer in the Ceduna Sub-basin and five areas of varying sizes are being released in the Otway Basin, including a deep water frontier offshore Victoria. The special release areas are located in the Petrel Sub-basin, Bonaparte Basin offshore Northern Territory, and encompass the Turtle/Barnett oil discoveries. The 2009 offshore acreage release offers a wide variety of block sizes in shallow as well as deep water environments. Area selection has been undertaken in consultation with industry, the states and Territory. This year’s acreage release caters for the whole gamut of exploration companies given that many areas are close to existing infrastructure while others are located in frontier offshore regions. As part of Geoscience Australia’s Offshore Energy Security Program, new data has been acquired in offshore frontier regions and have yielded encouraging insights into the hydrocarbon prospectivity of the Ceduna-Sub-basin.

The early history of the Proteaceae in Australia is traced from the record of fossil pollen that possess characters having taxonomic resolution among extant members of the family. Pollen characters useful for segregating subfamilies and generic groups are apertural number and form together with exine stratification and structure. When considered in conjunction with pollen shape, polarity, and size and exine sculpturing, they may be used to discriminate generic and/or species groups. The fossil pollen record suggests that the family originated in northern Gondwana during the late Cenomanian and radiated by as yet unidentified routes into southern high latitudes during the Turonian. There the family underwent substantial differentiation and expansion during Santonian–Maastrichtian times when at least four of the seven extant subfamilies evolved. Although diversification in Australia principally involved rainforest lineages (e.g. Macadamia–Helicia, Carnarvonia, Gevuina) ancestors of some sclerophyllous taxa (e.g. Adenanthos) also differentiated; this occurred in a regionalised vegetation of mesotherm open-forests in which podocarps and araucarians were important. Subsequent (Paleocene–Eocene) diversification and consolidation of the family may have focused on introduction and expansion of sclerophyllous lineages (e.g. Isopogon, Petrophile), but rainforest elements (e.g. Embothrium) were also involved. The associated vegetation, which was regionalised, experienced considerable floristic modifications during this time with introductions and/or expansion of an array of angiosperm taxa, notably Casuarinaceae, Myrtaceae and Nothofagus. In southern regions a marked decline in proteaceous pollen diversity and abundance occurred near the end of the Eocene, whereas in north-eastern regions the decline may have been later, during the Miocene.

In 2013, the Capricornia Arts Mob (CAM), an Indigenous collective of artists situated in Rockhampton, central Queensland, Australia, successfully tendered for one of three public art projects that were grouped under the title Flood Markers (Roberts; Roberts and Mackay; Robinson and Mackay). Commissioned as part of the Queensland Government's Community Development and Engagement Initiative, Flood Markers aims to increase awareness of Rockhampton’s history, with particular focus on the Fitzroy River and the phenomena of flooding. Honouring Land Connections is CAM’s contribution to the project and consists of several “memory poles” that stand alongside the Fitzroy River in Toonooba Park. Rockhampton lies on Dharumbal Country with Toonooba being the Dharumbal name for the Fitzroy River and the inspiration for the work due to its cultural significance to the Aboriginal people of that region. The name Toonooba, as well as other images and icons including boomerangs, spears, nets, water lily, and frogs, amongst others, are carved, burnt, painted and embedded into the large ironbark poles. These stand with the river on one side and the colonial infrastructure of Rockhampton on the other (see fig. 1, 2 and 3).Figure 1 Figure 2Figure 3Within this article, we discuss Honouring Land Connections as having two main functions which contribute to its significance as Indigenous cultural expression and identity affirmation. Firstly, the memory poles (as well as the process of sourcing materials and producing the final product) are a manifestation of Country and a representation of its stories and lived memories. Honouring Land Connections provides a means for Aboriginal people to revel in Country and maintain connections to a vital component of their being as Indigenous. Secondly, by revealing Indigenous stories, experiences, and memories, Honouring Land Connections emphasises Indigenous voices and perspectives within a place dominated by Eurocentric outlooks and knowledges. Toonooba provides the backdrop on which the complexities of cultural and identity formation within settler-colonial spaces are highlighted whilst revelling in continuous Indigenous presence.Flood Markers as ArtArtists throughout the world have used flood markers as a means of visual expression through which to explore and reveal local histories, events, environments, and socio-cultural understandings of the relationships between persons, places, and the phenomena of flooding. Geertz describes art as a social text embedded within wider socio-cultural systems; providing insight into cultural, social, political, economic, gendered, religious, ethnic, environmental, and biographical contexts. Flood markers are not merely metric tools used for measuring the height of a river, but rather serve as culture artefacts or indexes (Gell Art and Agency; Gell "Technology of Enchantment") that are products and producers of socio-culture contexts and the memories and experiences embedded within them. Through different methods, mediums, and images, artists have created experiential and intellectual spaces where those who encounter their work are encouraged to engage their surroundings in thought provoking and often-new ways.In some cases, flood markers have brought attention to the “character and natural history” of a particular place, where artists such as Louise Lavarack have sought to provoke consciousness of the movement of water across flood plains (Lavarack). In other works, flood markers have served as memorials to individuals such as Gilbert White whose daughter honoured his life and research through installing a glass spire at Boulder Creek, Colorado in 2011 (White). Tragedies such as Hurricane Katrina in New Orleans in 2005 have also been commemorated through flood markers. Artist Christopher Saucedo carved 1,836 waves into a freestanding granite block; each wave representing a life lost (University of New Orleans). The weight of the granite symbolises the endurance and resilience of those who faced, and will continue to face, similar forces of nature. The Pillar of Courage erected in 2011 in Ipswich, Queensland, similarly contains the words “resilience, community, strength, heroes, caring and unity” with each word printed on six separate sections of the pillar, representing the six major floods that have hit the region (Chudleigh).Whilst these flood markers provide valuable insights into local histories, specific to each environmental and socio-cultural context, works such as the Pillar of Courage fail to address Indigenous relationships to Country. By framing flooding as a “natural disaster” to be overcome, rather than an expression of Country to be listened to and understood, Euro and human-centric perspectives are prioritised over Indigenous ways of knowing and being. Indigenous knowledges however encourages a reorientation of Eurocentric responses and relationships to Country, and in doing so challenge compartmentalised views of “nature” where flooding is separated from land and Country (Ingold Perception; Seton and Bradley; Singer). Honouring Land Connections symbolises the voice and eternal presence of Toonooba and counters presentations of flooding that depict it as historian Heather Goodall (36) once saw “as unusual events of disorder in which the river leaves its proper place with catastrophic results.”Country To understand flooding from Indigenous perspectives it is first necessary to discuss Country and apprehend what it means for Indigenous peoples. Country refers to the physical, cosmological, geographical, relational, and emotional setting upon which Indigenous identities and connections to place and kin are embedded. Far from a passive geographic location upon which interactions take place, Country is an active and responsive agent that shapes and contextualises social interactions between and amongst all living beings. Bob Morgan writes of how “Country is more than issues of land and geography; it is about spirituality and identity, knowing who we are and who we are connected to; and it helps us understand how all living things are connected.” Country is also an epistemological frame that is filled with knowledge that may be known and familiarised whilst being knowledge itself (Langton "Sacred"; Rose Dingo; Yunupingu).Central to understanding Country is the fact that it refers to a living being’s spiritual homeland which is the ontological place where relationships are formed and maintained (Yunupingu). As Country nurtures and provides the necessities for survival and prosperity, Indigenous people (but also non-Indigenous populations) have moral obligations to care for Country as kin (Rose Nourishing Terrains). Country is epistemic, relational, and ontological and refers to both physical locations as well as modes of “being” (Heidegger), meaning it is carried from place to place as an embodiment within a person’s consciousness. Sally Morgan (263) describes how “our country is alive, and no matter where we go, our country never leaves us.” Country therefore is fluid and mobile for it is ontologically inseparable to one’s personhood, reflected through phrases such as “I am country” (B. Morgan 204).Country is in continuous dialogue with its surroundings and provides the setting upon which human and non-human beings; topographical features such as mountains and rivers; ancestral beings and spirits such as the Rainbow Snake; and ecological phenomena such as winds, tides, and floods, interact and mutually inform each other’s existence (Rose Nourishing Terrains). For Aboriginal people, understanding Country requires “deep listening” (Atkinson; Ungunmerr), a responsive awareness that moves beyond monological and human-centric understandings of the world and calls for deeper understandings of the mutual and co-dependant relationships that exist within it. The awareness of such mutuality has been discussed through terms such as “kincentrism” (Salmón), “meshworks” (Ingold Lines), “webs of connection” (Hokari), “nesting” (Malpas), and “native science” (Cajete). Such concepts are ways of theorising “place” as relational, physical, and mental locations made up of numerous smaller interactions, each of which contribute to the identity and meaning of place. Whilst each individual agent or object retains its own autonomy, such autonomy is dependent on its wider relation to others, meaning that place is a location where “objectivity, subjectivity and inter-subjectivity converge” (Malpas 35) and where the very essence of place is revealed.Flooding as DialogueWhen positioned within Indigenous frameworks, flooding is both an agent and expression of Toonooba and Country. For the phenomenon to occur however, numerous elements come into play such as the fall of rain; the layout of the surrounding terrain; human interference through built weirs and dams; and the actions and intervention of ancestral beings and spirits. Furthermore, flooding has a direct impact on Country and all life within it. This is highlighted by Dharumbal Elder Uncle Billy Mann (Fitzroy Basin Association "Billy Mann") who speaks of the importance of flooding in bringing water to inland lagoons which provide food sources for Dharumbal people, especially at times when the water in Toonooba is low. Such lagoons remain important places for fishing, hunting, recreational activities, and cultural practices but are reliant on the flow of water caused by the flowing, and at times flooding river, which Uncle Mann describes as the “lifeblood” of Dharumbal people and Country (Fitzroy Basin Association "Billy Mann"). Through her research in the Murray-Darling region of New South Wales, Weir writes of how flooding sustains life though cycles that contribute to ecological balance, providing nourishment and food sources for all beings (see also Cullen and Cullen 98). Water’s movement across land provokes the movement of animals such as mice and lizards, providing food for snakes. Frogs emerge from dry clay plains, finding newly made waterholes. Small aquatic organisms flourish and provide food sources for birds. Golden and silver perch spawn, and receding waters promote germination and growth. Aboriginal artist Ron Hurley depicts a similar cycle in a screen-print titled Waterlily–Darambal Totem. In this work Hurley shows floodwaters washing away old water lily roots that have been cooked in ant bed ovens as part of Dharumbal ceremonies (UQ Anthropology Museum). The cooking of the water lily exposes new seeds, which rains carry to nearby creeks and lagoons. The seeds take root and provide food sources for the following year. Cooking water lily during Dharumbal ceremonies contributes to securing and maintaining a sustainable food source as well as being part of Dharumbal cultural practice. Culture, ecological management, and everyday activity are mutually connected, along with being revealed and revelled in. Aboriginal Elder and ranger Uncle Fred Conway explains how Country teaches Aboriginal people to live in balance with their surroundings (Fitzroy Basin Association "Fred Conway"). As Country is in constant communication, numerous signifiers can be observed on land and waterscapes, indicating the most productive and sustainable time to pursue certain actions, source particular foods, or move to particular locations. The best time for fishing in central Queensland for example is when Wattles are in bloom, indicating a time when fish are “fatter and sweeter” (Fitzroy Basin Association "Fred Conway"). In this case, the Wattle is 1) autonomous, having its own life cycle; 2) mutually dependant, coming into being because of seasonal weather patterns; and 3) an agent of Country that teaches those with awareness how to respond and benefit from its lessons.Dialogue with Country As Country is sentient and responsive, it is vital that a person remains contextually aware of their actions on and towards their surroundings. Indigenous peoples seek familiarity with Country but also ensure that they themselves are known and familiarised by it (Rose Dingo). In a practice likened to “baptism”, Langton ("Earth") describes how Aboriginal Elders in Cape York pour water over the head of newcomers as a way of introducing them to Country, and ensuring that Country knows those who walk upon it. These introductions are done out of respect for Country and are a way of protecting outsiders from the potentially harmful powers of ancestral beings. Toussaint et al. similarly note how during mortuary rites, parents of the deceased take water from rivers and spit it back into the land, symbolising the spirit’s return to Country.Dharumbal man Robin Hatfield demonstrates the importance of not interfering with the dialogue of Country through recalling being told as a child not to disturb Barraru or green frogs. Memmott (78) writes that frogs share a relationship with the rain and flooding caused by Munda-gadda, the Rainbow Snake. Uncle Dougie Hatfield explains the significance of Munda-gadda to his Country stating how “our Aboriginal culture tells us that all the waterways, lagoons, creeks, rivers etc. and many landforms were created by and still are protected by the Moonda-Ngutta, what white people call the Rainbow Snake” (Memmott 79).In the case of Robin Hatfield, to interfere with Barraru’s “business” is to threaten its dialogue with Munda-gadda and in turn the dialogue of Country in form of rain. In addition to disrupting the relational balance between the frog and Munda-gadda, such actions potentially have far-reaching social and cosmological consequences. The rain’s disruption affects the flood plains, which has direct consequences for local flora and transportation and germination of water lily seeds; fauna, affecting the spawning of fish and their movement into lagoons; and ancestral beings such as Munda-gadda who continue to reside within Toonooba.Honouring Land Connections provided artists with a means to enter their own dialogue with Country and explore, discuss, engage, negotiate, and affirm aspects of their indigeneity. The artists wanted the artwork to remain organic to demonstrate honour and respect for Dharumbal connections with Country (Roberts). This meant that materials were sourced from the surrounding Country and the poles placed in a wave-like pattern resembling Munda-gadda. Alongside the designs and symbols painted and carved into the poles, fish skins, birds, nests, and frogs are embalmed within cavities that are cut into the wood, acting as windows that allow viewers to witness components of Country that are often overlooked (see fig. 4). Country therefore is an equal participant within the artwork’s creation and continuing memories and stories. More than a representation of Country, Honouring Land Connections is a literal manifestation of it.Figure 4Opening Dialogue with Non-Indigenous AustraliaHonouring Land Connections is an artistic and cultural expression that revels in Indigenous understandings of place. The installation however remains positioned within a contested “hybrid” setting that is informed by both Indigenous and settler-colonial outlooks (Bhabha). The installation for example is separated from the other two artworks of Flood Markers that explore Rockhampton’s colonial and industrial history. Whilst these are positioned within a landscaped area, Honouring Land Connections is placed where the grass is dying, seating is lacking, and is situated next to a dilapidated coast guard building. It is a location that is as quickly left behind as it is encountered. Its separation from the other two works is further emphasised through its depiction in the project brief as a representation of Rockhampton’s pre-colonial history. Presenting it in such a way has the effect of bookending Aboriginal culture in relation to European settlement, suggesting that its themes belong to a time past rather than an immediate present. Almost as if it is a revelation in and of itself. Within settler-colonial settings, place is heavily politicised and often contested. In what can be seen as an ongoing form of colonialism, Eurocentric epistemologies and understandings of place continue to dominate public thought, rhetoric, and action in ways that legitimise White positionality whilst questioning and/or subjugating other ways of knowing, being, and doing (K. Martin; Moreton-Robinson; Wolfe). This turns places such as Toonooba into agonistic locations of contrasting and competing interests (Bradfield). For many Aboriginal peoples, the memories and emotions attached to a particular place can render it as either comfortable and culturally safe, or as unsafe, unsuitable, unwelcoming, and exclusionary (Fredericks). Honouring Land Connections is one way of publicly asserting and recognising Toonooba as a culturally safe, welcoming, and deeply meaningful place for Indigenous peoples. Whilst the themes explored in Honouring Land Connections are not overtly political, its presence on colonised/invaded land unsettles Eurocentric falsities and colonial amnesia (B. Martin) of an uncontested place and history in which Indigenous voices and knowledges are silenced. The artwork is a physical reminder that encourages awareness—particularly for non-Indigenous populations—of Indigenous voices that are continuously demanding recognition of Aboriginal place within Country. Similar to the boomerangs carved into the poles representing flooding as a natural expression of Country that will return (see fig. 5), Indigenous peoples continue to demand that the wider non-Indigenous population acknowledge, respect, and morally responded to Aboriginal cultures and knowledges.Figure 5Conclusion Far from a historic account of the past, the artists of CAM have created an artwork that promotes awareness of an immediate and emerging Indigenous presence on Country. It creates a space that is welcoming to Indigenous people, allowing them to engage with and affirm aspects of their living histories and cultural identities. Through sharing stories and providing “windows” into Aboriginal culture, Country, and lived experiences (which like the frogs of Toonooba are so often overlooked), the memory poles invite and welcome an open dialogue with non-Indigenous Australians where all may consider their shared presence and mutual dependence on each other and their surroundings.The memory poles are mediatory agents that stand on Country, revealing and bearing witness to the survival, resistance, tenacity, and continuity of Aboriginal peoples within the Rockhampton region and along Toonooba. Honouring Land Connections is not simply a means of reclaiming the river as an Indigenous space, for reclamation signifies something regained after it has been lost. What the memory poles signify is something eternally present, i.e. Toonooba is and forever will be embedded in Aboriginal Country in which we all, Indigenous and non-Indigenous, human and non-human, share. The memory poles serve as lasting reminders of whose Country Rockhampton is on and describes the life ways of that Country, including times of flood. Through celebrating and revelling in the presence of Country, the artists of CAM are revealing the deep connection they have to Country to the wider non-Indigenous community.ReferencesAtkinson, Judy. Trauma Trails, Recreating Song Lines: The Transgenerational Effects of Trauma in Indigenous Australia. Spinifex Press, 2002.Bhabha, Homi, K. The Location of Culture. Taylor and Francis, 2012.Bradfield, Abraham. "Decolonizing the Intercultural: A Call for Decolonizing Consciousness in Settler-Colonial Australia." Religions 10.8 (2019): 469.Cajete, Gregory. Native Science: Natural Laws of Interdependence. 1st ed. 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