B. G. Jones

Identification of historical lead sources in roof dusts and recent lake sediments from an industrialized area: indications from lead isotopes

X-ray fluorescence and stable lead (Pb) isotopic analyses have been undertaken on dusts, known from microscopic investigation to contain significant quantities of industrially- and urban-derived particulate matter, present in the roof cavities of houses in the Illawarra region (N.S.W., Australia), with the objective of examining the historic record of Pb pollution. All investigated houses contained in excess of 250 micrograms g-1 Pb, with dwellings close to a copper smelter, in a large industrial complex including a major steelworks, containing higher (> 2500 micrograms g-1) Pb concentrations. The isotopic composition in the dusts, expressed here as 206Pb/204Pb, is relatively constant at 17.0, irrespective of dwelling age or distance from the industrial complex. Contamination of the dusts by Pb sourced from paint cannot explain the isotopic uniformity of the dust samples. Isotopic modelling indicates that the dusts contain Pb derived from the copper smelter, gasoline-air Pb and a minor contribution from coal-utilising sources. Lead loading was also investigated in the adjacent lagoon, which acts as a natural sink for particulate matter in the Illawarra region. Isotopic data and modelling indicate that one natural and four anthropogenic sources contribute to the Pb burden of this lagoon. The natural source consists of Permian rocks cropping out in the catchment area which have a 206Pb/204Pb of approximately 18.7. The suggested anthropogenic sources are an old disbanded base-metal (Pb) smelter (206Pb/204Pb approximately 16.2-16.3), the copper smelter (206Pb/204Pb approximately 17.9), gasoline-air derived Pb (206Pb/204Pb approximately 16.4-16.5) and industries utilising coal, for example the recently closed thermal coal-fired power station (206Pb/204Pb approximately 18.9). The relative contributions of the base-metal (mainly lead) smelter and gasoline-air Pb in the sediment can only be partly assessed due to the isotopic similarity of these sources. Likewise the natural background and coal source (e.g. power station) contributions can only be estimated from historical data. Age estimations for sediment cores, using 137Cs, provide some control on these assessments. Near surface sediments in the lagoon have a relatively constant 206Pb/204Pb of 17.6-17.7, irrespective of sample location. Isotopic calculations, together with records of particulate matter pollution emissions, indicate a link between the Pb in roof dusts (206Pb/204Pb approximately 17.0) and Pb contamination of the near surface (upper 20 cm) lagoonal sediments via a homogeneous, non-unique source of lead whose isotopic composition closely matches that of the dusts. Over the last 5 decades, atmospheric fallout of Pb-bearing particulate matter appears to have been the dominant pathway for addition of Pb to the lagoon and dwellings in the Illawarra region.

Stratigraphy and sedimentology of the Permian Talaterang and Shoalhaven Groups in the southernmost Sydney Basin, New South Wales

The Permian (Sakmarian‐Artinskian) Talaterang and Shoalhaven Groups form the basal part of the Sydney Basin succession at its southernmost onshore extremity. A new stratigraphic model is proposed for the southern Sydney Basin and, although the previous group division is retained, considerable rearrangement of formations within and between the groups has been necessary as a result of recent field work. The Talaterang Group now includes the Clyde Coal Measures (incorporating the previous Pigeon House Creek Siltstone) and the Wasp Head Formation. The lower units in the overlying Shoalhaven Group are the Yadboro and Tallong Conglomerates, Pebbley Beach Formation, Yarrunga Coal Measures and Snapper Point Formation. Within the Talaterang Group, north‐directed sediment dispersal in the mud‐rich alluvial Clyde Coal Measures sequence and high energy east‐directed debris flows in the Wasp Head Formation suggest axial and transverse drainage related to possible north‐trending extensional (rift) sub‐basins similar to...

Geochemical comparisons between estuaries with non‐industrialised and industrialised catchments: The Huon and Derwent River estuaries, Tasmania

The adjacent Huon and Derwent estuaries in Tasmania have similar climatic and physical characteristics, and provide a good comparison between relatively uncontaminated and industrially polluted estuaries, respectively. Representative samples were collected from both estuaries and analysed for grainsize and trace‐element content (using X‐ray fluorescence and neutron activation analyses). The Huon estuary drains a predominantly forested and agricultural catchment and contains low (baseline) concentrations of trace elements, including lead, zinc and copper. In contrast, the Derwent estuary has a geologically similar yet larger catchment and it passes through an industrialised area in the midestuarine reach. A zinc refinery has, in the past, been a major source of trace‐element contamination. These contaminants are distributed downstream from the refinery by combined fluvial and tidal activity, while the latter also causes upstream movement of contaminants during non‐flood periods. Significant upstream contamination is limited by fluvial bottom flows remobilising contaminated fine sediment during flood periods. Maximum contamination occurs in the region around the refinery with values in the surface sediments ranging from 40 to 565 times baseline levels and from 2 to 55 times the Australian Interim Sediment Quality Guidelines high‐levels for aquatic sediments (maximum 22593 ppm Zn, 3866 ppm Pb and 1182 ppm Cu). In the lower Derwent estuary, contaminant distribution is inversely related to tidal‐flow velocities and is most prominent in the lower energy muddy substrates. Trace‐metal levels in the more recent surficial aquatic sediments are slightly lower than those recorded in a previous study from the area, possibly reflecting the stricter environmental controls now operating.

Anthropogenic marker evidence for accelerated sedimentation in Lake Illawarra, New South Wales, Australia

The chronology of near-surface sediments in Lake Illawarra has been investigated using radiocarbon dating and anthropogenically derived substances including trace metals, ash, and137Cs. Sediments at depths about 1 m below the water-sediment interface ranged in age from Modern to 786 calendar years bp on the basis of radiocarbon dating ofNotospisula trigonella valves. Multiple marker (for example ash-trace metals) depth-concentration sediment profiles yielded estimates of sedimentation rate ranging from 3 to 5 mm yr−1 at Griffins Bay to more than 16 mm yr−1 at Macquarie Rivulet. Sedimentation rates of approximately 10 mm yr−1 appeared to be typical of the western and southwestern portions of the lagoon. Rates of sediment accretion, prior to catchment clearing, urbanization, and industrialization have been estimated at less than 1 mm yr−1, thus indicating a general tenfold increase in sediment accumulation adjacent to the western foreshore caused by catchment development. Accelerated sedimentation in shallow coastal lagoons constitutes significant environmental impacts including shoaling, degradation of seagrass beds, and increased turbidity with consequent loss of aesthetic appeal. Management policy should be directed at attempts to reduce the amount of sediment input by the construction of strategically placed sediment retention ponds. Siltation within the shallow embayments of Lake Illawarra could be ameliorated by a carefully planned program of dredging.

Heavy metal concentrations in lagoonal saltmarsh species, Illawarra region, southeastern Australia

Abstract The importance of saltmarsh environments and their floral communities lies in their ability to act as a buffer between land and aquatic systems. Runoff from rural and urban areas, the generation of power and heavy industry all contribute pollutants to the Wollongong coastal Zone, where heavy metal contents in saltmarsh substrates are found to be up to 200 times greater than at localities on the south coast of NSW. The saltmarsh species Sarcocornia quinqueflora , Suaeda australis and Triglochin striata show enhanced levels of Cu, Zn, Pb, Cd, Cr and Mn in the Wollongong area relative to sites at Callala Bay and Burrill Lake. This trend reflects, but is much lower than, levels of these metals in the substrate. Cu, Zn and Pb are concentrated in the horizontal stems of Sarcocornia and the leaves of Suaeda , but both are lower than levels in Triglochin . The elevated Cu and Zn levels in plants at Bellambi Lagoon are probably derived from urban runoff as there is no current industrial source of pollution within the catchment. The type of pollutant affects the bioavailability of the heavy metals. Industrial airborne particulate pollutants generally require considerable acidic leaching before the metals become available to the biological community. These processes only occur to a limited extent in a natural ecosystem and hence account for low uptake of heavy metals by plants in the anoxic environment at Griffins Bay. Saltmarshes act as low energy coastal sediment traps and, together with the plants, effectively reduce the amount of bioavailable pollutants being transferred into the aquatic environment. Analysis of saltmarsh species can rapidly provide very important information about the bioavailability of metal pollutants in marginal marine environments and they have considerable potential as monitors of diverse sources of pollution.

The Influence of Palaeoenvironment and lava flux on the emplacement of submarine, near-shore Late Permian basalt lavas, Sydney Basin (Australia)

Abstract Lava flux and a low palaeoslope were the critical factors in determining the development of different facies in the Late Permian Blow Hole flow, which comprises a series of shoshonitic basalt lavas and associated volcaniclastic detritus in the southern Sydney Basin of eastern Australia. The unit consists of a lower lobe and sheet facies, a middle tube and breccia facies, and an upper columnar-jointed facies. Close similarities in petrography and geochemistry between the basalt lavas from the three facies suggest similar viscosities at similar temperatures. Sedimentological and palaeontological evidence from the sedimentary units immediately below the Blow Hole flow suggests that the lower part of the volcanic unit was emplaced in a cold water, shallow submarine environment, but at least the top of the uppermost lava was subaerial with some palaeosol development. The lower lobe and sheet facies was emplaced on a low slope (

Thermoluminescence ages for a reworked coastal barrier, southeastern Vietnam: a preliminary report

Thermoluminescence dating of quartz sand (90-125 ?m) from the coastal barrier successions between Phan Thiet and Tuy Phong, southeastern Vietnam, reveals that a substantial component was deposited during the last interglacial sensu lato (Oxygen Isotope Stage 5) between 108 and 85 ka. The barrier successions have subsequently, in places, experienced multiple phases of aeolian reworking during the last glacial cycle, and in particular between 62 and 19 ka, possibly related to reduced vegetation cover and landscape instability caused by climatic change. The difficulties of applying the thermoluminescence (TL) method in areas of intense tropical weathering are also examined. ?? 2002 Elsevier Science Ltd. All rights reserved. Author Keywords: Coastal barrier deposition; Quaternary; Thermoluminescence dating; Vietnam Index Keywords: coastal landform; Last Interglacial; paleoclimate; paleoenvironment; Quaternary; sand; thermoluminescence; Viet Nam

Evolution of the early devonian bindook volcanic complex, wollondilly basin, eastern lachlan fold belt

The Early Devonian Bindook Volcanic Complex consists of a thick silicic volcanic and associated sedimentary succession filling the extensional Wollondilly Basin in the northeastern Lachlan Fold Belt. The basal part of the succession (Tangerang Formation) is exposed in the central and southeastern Wollondilly Basin where it unconformably overlies Ordovician rocks or conformably overlies the Late Silurian to Early Devonian Bungonia Limestone. Six volcanic members, including three new members, are now recognised in the Tangerang Formation and three major facies have been delineated in the associated sedimentary sequence. The oldest part of the sequence near Windellama consists of a quartz turbidite facies deposited at moderate water depths together with the shallow‐marine shelf Windellama Limestone and Brooklyn Conglomerate Members deposited close to the eastern margin of the basin. Farther north the shelf facies consists of marine shale and sandstone which become progressively more tuffaceous northwards tow...