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An attempt has been made at a comprehensive study of the diversity and distribution of subterranean ostracods in the Pilbara region, northwestern Australia. The area is a “hot spot” for subterranean biodiversity, some of which is currently under threat from extensive mining operations. Both bore and well sites were targeted, totalling 445 sites, to obtain a thorough coverage of the 200,000 km2. In addition, physical and hydrochemical measurements were obtained for all of the samples (temperature, conductivity, dissolved oxygen, pH, Eh, turbidity, nutrients, major ions). Ostracods were retrieved from approximately 47% of the samples and 56% of the sites. Twenty-one genera and around 110 species of ostracods have been identified. Of these, 72 are new species and a further 10 are currently in open nomenclature, due to the lack of suitable material for formal taxonomic description. The Candoninae are particularly well represented with 12 genera; some, such as Areacandona and Deminutiocandona, with 25 and 10 species respectively. Most sites (80%) were dominated by only one or two species, with up to six species at some sites. Population density varied from 1–370 individuals/sample. The most abundant and diverse sites occur in fresh, bicarbonate-rich aquifers utilised for water extraction, such as Pannawonica (Robe River), Cane River and Millstream. There is a clear distinction between taxa at the genus level from coastal and low-lying alluvial sites, and upland sites (>300 m altitude). Beyond this, the majority of species are confined within a surface water catchment, or in many cases, a specific aquifer. There are, however, some morphological similarities of the carapaces between different species within similar hydrogeologic settings. Ornate and ridged-valved species are common in the Mg–HCO3 waters of the Newman and Marillana Creek areas, whereas smooth-shelled, tapered forms are prevalent in alluvial aquifers. The more saline, Na–Cl rich aquifers at the edge of Great Sandy Desert have a particularly distinctive fauna, including one almost triangular species. The distribution of the stygobitic ostracod species in relation to the hydrogeology and water chemistry is discussed.

The Gulf of Carpentaria is an epicontinental sea (maximum depth 70 m) between Australia and New Guinea, bordered to the east by Torres Strait (currently 12 m deep) and to the west by the Arafura Sill (53 m below present sea level). Throughout the Quaternary, during times of low sea-level, the Gulf was separated from the open waters of the Indian and Pacific Oceans, forming Lake Carpentaria, an isolation basin, perched above contemporaneous sea-level with outlet channels to the Arafura Sea. A preliminary interpretation is presented of the palaeoenvironments recorded in six sediment cores collected by the IMAGES program in the Gulf of Carpentaria. The longest core (approx. 15 m) spans the past 130 ka and includes a record of sea-level/lake-level changes, with particular complexity between 80 and 40 ka when sea-level repeatedly breached and withdrew from Gulf/Lake Carpentaria. Evidence from biotic remains (foraminifers, ostracods, pollen), sedimentology and geochemistry clearly identifies a final marine transgression at about 9.7 ka (radiocarbon years). Before this transgression, Lake Carpentaria was surrounded by grassland, was near full, and may have had a surface area approaching 600 km×300 km and a depth of about 15 m. The earlier rise in sea-level which accompanied the Marine Isotopic Stage 6/5 transgression at about 130 ka is constrained by sedimentological and biotic evidence and dated by optical- and thermoluminescence and amino acid racemisation methods.

Environmental evolution of the Gulf of Carpentaria region, the world's largest tropical epicontinental seaway, through the last glacial cycle has been determined from a series of six sediment cores. These cores form the focus of a multi-disciplinary study to elucidate sea level, climate and environmental change in the region. The sedimentary record reveals a series of facies including open shallow marine, marginal marine, estuarine, lacustrine and subaerial exposure, throughout the extent of the basin during this period.The partial or complete closure of the central basin from marine waters results from sea level falling below the height of one or both of the sills that border the Gulf—the Arafura Sill to the west (53 m below present sea level (bpsl)) and Torres Strait to the east (12 m bpsl). The extent and timing of these closures, and restriction of the shallow waterbody within, are intrinsic to local ocean circulation, available latent heat transport and the movement of people and animals between Australia and New Guinea.Whilst the occurrence of the palaeo-Lake Carpentaria has previously been identified, this study expands on the hydrological conditions of the lacustrine phases and extends the record through the Last Interglacial, detailing the previous sea-level highstand (MIS 5.5) and subsequent retreat.When sea levels were low during the MIS 6 glacial period, the Gulf was largely subaerially exposed and traversed by meandering rivers. The MIS 5 transgression (∼130 ka BP) led to marine then alternating marine/estuarine conditions through to MIS 4 (∼70 ka BP) when a protracted lacustrine phase, of varying salinity and depth/area, and including periods of near desiccation, persisted until about 12.2 cal ka BP. The lake expanded to near maximum size (∼190 000 km2) following the intensification/restoration of the Australian monsoon at 14 ka BP. This lake-full phase was short-lived, as by 12.2 cal ka BP, marine waters were entering the basin, coincident with the progressive sea-level rise. Fully marine conditions were restored by about 10.5 cal ka BP by westward connection to the Arafura Sea (Indian Ocean), whereas connections to the Pacific Ocean (Coral Sea) did not occur until about 8 cal ka BP.

During routine chemical analyses of the stalked ibliform barnacle Chaetolepas calcitergum Buckeridge & Newman 2006, peaks of more than 7% (by dry mass) of bromine were detected. Although bromine ions occur in seawater (up to 66 ppm), this level of accumulation, in the soft tissue of the barnacle, is extraordinary. Organic concentration of bromine compounds occurs in a number of invertebrates, such as algae and sponges, but this is the first record of elevated bromine in goose barnacles. The high accumulation of bromine compound(s) is most likely a defense mechanism. The present paper includes a review of the mechanisms deployed by barnacles to repel predators.

Drawing on the recent synthesis of Australian palaeoclimate by the OZ-INTIMATE group (Reeves et al. 2013a), we consider the effects of climate systems on past human settlement patterns and inferred demography. We use 5,044 radiocarbon dates from ~1,750 archaeological sites to develop regional time-series curves for different regions defined in the OZ-INTIMATE compilation as the temperate, tropics, interior and Southern Ocean sectors to explore human-climate relationships in Australia over the last 35,000 years. Correlations undertaken with improved palaeoclimatic data and archaeological records indicate that the regional time-series curves are robust, and can be used as a proxy for human behaviour. However, interrogation of the datasets is essential with artificial peaks and taphonomic over-correction being critical considerations. The time-series curves are interpreted as reflecting population growth, stasis and even decline in phase with terminal Pleistocene/early Holocene climatic fluctuations. This coupling, however, decreases during the last 5,000 years, most likely due to increased population levels, greater territoriality, technological solutions to stress, and social and ideational innovation. Curves from all sectors show exponential population growth over the last 5,000 years. We identify future research priorities, highlighting the paucity of archaeological records across several parts of Australia (<1 dated site/4,000km2), especially around the fringes of the arid zone, and the need for improved taphonomic correction techniques. Finally, we discuss how these time-series curves represent a first-order framework, not dissimilar to global climate models, which researchers can continue to test and refine with local, regional and continental records.

Abstract Temperate Australia sits between the heat engine of the tropics and the cold Southern Ocean, encompassing a range of rainfall regimes and falling under the influence of different climatic drivers. Despite this heterogeneity, broad-scale trends in climatic and environmental change are evident over the past 30 ka. During the early glacial period (∼ 30–22 ka) and the Last Glacial Maximum (∼ 22–18 ka), climate was relatively cool across the entire temperate zone and there was an expansion of grasslands and increased fluvial ...