ORCID Profile
0000-0002-9235-0360
Current Organisations
CSIRO Mineral Resources, Adelaide, SA
,
University of Adelaide School of Biological Sciences
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CSIRO
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Publisher: Wiley
Date: 09-1985
Publisher: Elsevier BV
Date: 12-2018
Publisher: Elsevier BV
Date: 05-2016
Publisher: CSIRO Publishing
Date: 2006
DOI: 10.1071/MF06057
Abstract: Due to a combination of river regulation, dryland salinity and irrigation return, lower River Murray floodplains (Australia) and associated wetlands are undergoing salinisation. It was hypothesised that salinisation would provide suitable conditions for the accumulation of sulfidic materials (soils and sediments enriched in sulfides, such as pyrite) in these wetlands. A survey of nine floodplain wetlands representing a salinity gradient from fresh to hypersaline determined that surface sediment sulfide concentrations varied from .05% to ~1%. Saline and permanently flooded wetlands tended to have greater sulfide concentrations than freshwater ones or those with more regular wetting–drying regimes. The acidification risk associated with the sulfidic materials was evaluated using field peroxide oxidations tests and laboratory measurements of net acid generation potential. Although sulfide concentration was elevated in many wetlands, the acidification risk was low because of elevated carbonate concentration (up to 30% as CaCO3) in the sediments. One exception was Bottle Bend Lagoon (New South Wales), which had acidified during a draw-down event in 2002 and was found to have both actual and potential acid sulfate soils at the time of the survey (2003). Potential acid sulfate soils also occurred locally in the hypersaline Loveday Disposal Basin. The other environmental risks associated with sulfidic materials could not be reliably evaluated because no guideline exists to assess them. These include the deoxygenation risk following sediment resuspension and the generation of foul odours during drying events. The remediation of wetland salinity in the Murray–Darling Basin will require that the risks associated with disturbing sulfidic materials during management actions be evaluated.
Publisher: CSIRO Publishing
Date: 2009
DOI: 10.1071/SR07015
Abstract: Soil micromorphology, using light microscopy and scanning electron microscopy (SEM), was used to describe detailed soil morphological and compositional changes and determine mineral weathering pathways in acid sulfate soils (ASS) from the following 2 contrasting coastal environments in Barker Inlet, South Australia: (i) a tidal mangrove forest with sulfidic material at St Kilda, and (ii) a former supratidal s hire area at Gillman that was drained in 1954 causing sulfuric material to form from sulfidic material. Pyrite framboids and cubes were identified in sulfidic material from both sites and are associated with sapric and hemic materials. Gypsum crystals, interpreted as a product of sulfide oxidation, were observed to have formed in lenticular voids within organic matter in the tidal mangrove soils at St Kilda. Sulfide oxidation was extensive in the drained soil at Gillman, evidenced by the formation of iron oxyhydroxide pseudomorphs (goethite crystallites and framboids) after pyrite and jarosite, and of gypsum crystals. Gypsum crystals occur where a local source of calcium such as shells or calcareous sand is present. Sporadic oxidation episodes are indicated by the formation of iron oxide and jarosite coatings around coarse biogenic voids. These observations indicate that mineral transformation pathways are strongly influenced by soil physico-chemical characteristics (i.e. oxidation rate, Eh, pH, soil solution chemistry, mineralogy, and spatial distribution of sulfides). This information has been used to illustrate the interrelationships of pyrite, carbonate, gypsum, jarosite, and organic matter and help predict soil evolution under changing hydro-geochemical, redoximorphic, and thermal conditions in soils from coastal environments.
Publisher: Springer Science and Business Media LLC
Date: 12-2005
Publisher: CSIRO Publishing
Date: 1992
DOI: 10.1071/EA9920992Z
Abstract: No abstract available.
Publisher: Elsevier BV
Date: 06-2016
Publisher: CSIRO Publishing
Date: 2002
DOI: 10.1071/SR02008
Abstract: This paper is the first of two describing how soil macromorphological and chemical data can be combined with a minimum of hydrological data to distinguish between, and to quantify, past and present hydrological processes. These processes are relevant to both waterlogging and dryland salinity. The purpose of this first paper is to establish a methodological framework. It also describes the initial interpretation of the macromorphological features of the toposequence studied at Gatum on the Dundas Tablelands in western Victoria. A modified version of the soil feature–system–domain grouping method was used. Macromorphological data combined with only limited piezometric data showed that: (1) The soil feature–system–domain grouping method makes it possible to distinguish between the effects of past and present hydrological processes on soil macromorphology at Gatum. (2) Waterlogging of the surface horizons at Gatum is often caused by perching of soil water within the B-horizon (as opposed to on top of the B-horizon). Changes in soil structure and in colour of cutans and mottles can be an indicator of this first restricting layer. (3) It is likely that interpedal cracks and old tree root holes act as preferred paths for water to flow through this first restricting layer. (4) A second fresh perched water table can occur on top of the pallid zone. Where the pallid zone reaches close to the surface the two perched water tables may merge and cause a local increase in waterlogging, as indicated by local soil morphology. When this occurs, hillside seeps can occur quite high up on the slopes, even when there is no apparent irregularity in surface topography. (5) The permanent saline water table occurs on top of the bedrock and causes salting problems where it comes too close to the soil surface. Salting problems at the bottom of a slope are more severe where fresh perched water tables increase waterlogging On the basis of these findings the suitability of various management options to reduce waterlogging and salinisation is discussed. Further findings regarding restricting layers, flow paths through the soils, and relations between duration of saturation and soil morphological features, are discussed in a companion paper (by J. Brouwer and R. W. Fitzpatrick, pp. 927-946 in this issue).
Publisher: CSIRO Publishing
Date: 2002
DOI: 10.1071/SR02009
Abstract: This paper is the second of two describing how soil macromorphological and chemical data can be combined with soil hydrological data to distinguish between, and to quantify, past and present hydrological processes relevant to waterlogging and dryland salinity. The first paper provides a methodological framework for the study, and describes the initial interpretation of the macromorphological features of the toposequence studied, using the soil feature-system-domain grouping method. This second paper deals with the added value of extensive piezometric and other hydrological observations relative to soil macromorphological studies, and with quantitative relationships between soil colour and duration of waterlogging. As with the first paper, this paper focuses on a soil toposequence at Gatum on the eastern Dundas Tableland in western Victoria. For the the broad crest with yellow gradational soils or Dermosols (Plinthoxeralfs), the hydrological data confirmed the conclusion from macromorphological observations that: (1) There are three levels at which downward flow of water is restricted: at the top of the largely unaltered mottled zone, that is at 0.8-1.0 m depth, well below the top of the yellow Bt1-horizon (fresh water) at the top of the pallid zone, at about 3-3.5 m depth (fresh water) and on top of the unweathered ignimbrite (saline water). (2) Below about 30 mm depth, down at least as far as 2.0 m and sometimes even more, the major pathways for downward movement of water are indeed root channels, with or without live roots, and not interpedal cracks. The 3-dimensional spacing of the rootholes above and through the less-permeable mottled zone, and the (horizontal) conductivity, storage capacity, and thickness of overlying horizons determine the extent of ponding, runoff, and deep infiltration taking place. In addition, the hydrological observations showed that: (3) If rainfall is regular, well-spaced, and not excessive, ponding is unlikely to take place even where there is a rainfall surplus and there are layers restricting downward flow of water. Furthermore, along the toposequence with yellow duplex soils or Dermosols, Chromosols, and Hydrosols, (4) There were generally good correlations between duration of saturation at the bottom of the E-horizon and colour aspects of the E-horizon (value and chroma of the matrix) and of the B2-horizon (hue, value, and chroma of the matrix). Based on these findings additional suggestions are made for improving identification and management of water logging and salinisation processes.
Publisher: Wiley
Date: 14-07-2017
DOI: 10.1111/SUM.12362
Publisher: Informa UK Limited
Date: 02-07-2016
Publisher: Elsevier BV
Date: 08-2016
Publisher: Elsevier BV
Date: 08-1991
Publisher: Wiley
Date: 30-12-2012
DOI: 10.1111/SUM.12019
Publisher: Wiley
Date: 05-03-2009
DOI: 10.1002/9780470061589.FSA096.PUB2
Abstract: Earth materials such as soils, rocks, minerals, and particles from man‐made materials such as bricks provide excellent evidence to link criminals to crime scenes. Forensic soil scientists are also using advanced automated techniques, which have the ability to acquire information from smaller s les to make soil forensics an increasingly popular tool in criminal investigations. The aim of soil forensic analysis is to associate soil, rock, or mineral s les taken from an item, such as shoes, clothing, shovel, or vehicle with a specific location. Soil materials are powerful, perhaps ideal, pieces of contact trace evidence to help in criminal investigations. Soil forensic investigations usually involve collection of one or more soil s les followed by soil characterization. Collected s les are categorized as (i) questioned soil s les whose origin is unknown or disputed (suspect or victim), (ii) control soil s les whose origin is known (crime scene), and (iii) alibi soil s les whose origin is known and that provide a measure of the distinctiveness of the questioned and control s les. Soil characterization often requires the following four‐stage approach, which combines descriptive, analytical, and spatial information: (i) Initial characterization for screening of s les involving morphological descriptions. (ii) Semi‐detailed characterization involving semi‐quantification of minerals and organic matter following s le selection and size fractionation ( µm). (iii) Detailed characterization and quantification of minerals and organic matter using additional analytical techniques and/or methods of s le preparation, separation, or concentration such as size or magnetic or heavy mineral fractionation. (iv) Integration and extrapolation of soil information from one scale to the next, to build a coherent model of soil information from microscopic observations to the landscape scale, which often involves soil/geological maps and geophysics. Progression of a soil forensic examination through each of the four stages will depend on the amount of s le available and the results from the early stages of the examination. The significance and relevance of established concepts and standard terminologies used in soil science and geology with practical relevance to forensic science are emphasized.
Publisher: Wiley
Date: 11-1991
Publisher: Springer Science and Business Media LLC
Date: 18-02-1999
Publisher: Wiley
Date: 02-2011
Publisher: Wiley
Date: 12-1994
Publisher: Springer Science and Business Media LLC
Date: 10-2015
Publisher: Elsevier BV
Date: 12-2017
Publisher: CSIRO Publishing
Date: 2009
DOI: 10.1071/SR06106
Abstract: Acid sulfate soils (ASS) occupy an estimated 5.8 × 106 ha of coastal Australia. In tropical Australia, the processes operating in these soils, and their environmental hazards, are poorly understood. Drainage of a tropical estuarine wetland containing extensive ASS deposits left the area in a highly degraded condition. Surface and soil water pH values from the site were consistently and commonly .5. Aluminium activity was several orders of magnitude greater than the level set for the protection of aquatic ecosystems, with a seasonal variation of 3 orders of magnitude. Aluminium behaved conservatively at the discharge point to receiving waters. In drainage lines and soil solution, aluminium activity was limited by elevated sulfate activity. Aluminium was commonly supersaturated with respect to alunite and behaved as though an aluminium species with the stoichiometry Al:OH:SO4 regulated its activity, which was 2–5 orders of magnitude lower than if gibbsite or amorphous aluminium hydroxide solubility was the control. While jurbanite (AlOHSO4.5H2O) is no longer considered a potential mineral in ASS, these data again raise the question of a satisfactory explanation of aluminium activity. Sulfate activity was influenced by seasonal factors. Wet season conditions were reducing and favoured the dissolution of acid iron oxidation products. The dry season oxidising and drying conditions favoured their precipitation, resulting in seasonal cycling. Based on our findings we developed a landscape geochemical process model for the site.
Publisher: Springer Science and Business Media LLC
Date: 25-10-2018
Publisher: CSIRO Publishing
Date: 1995
DOI: 10.1071/SR9950415
Abstract: An inert electrode was constructed using wax-impregnated graphite (WIG) as an alternative to Pt for permanent installation in the regolith. The performance of WIG electrodes has not previously been systematically evaluated by using data from field trials, although Pt and WIG measure similar Eh values in laboratory solutions. We compared the performance of the WIG electrode when installed adjacent to Pt redox electrodes in the A, B and C horizons of duplex soils in a X-eralf-Aqualf toposequence near Mount Crawford in the Mt Lofty Ranges, South Australia. Lower potentials, commonly in the order of 200 mV, were measured from WIG electrodes, relative to Pt electrodes. Measurements of potential from adjacently installed WIG and Pt electrodes did not show significant correlation. Generally oxidizing redox potentials were measured in all soils in which electrodes were installed due to below average rainfall during the s ling period. Further testing of WIG electrodes in reduced regolith is needed. Interpretation of Eh trends, measured using Pt electrodes, between the A, B and C horizon are presented.
Publisher: Elsevier BV
Date: 12-2017
Publisher: Wiley
Date: 10-07-2012
Publisher: Elsevier BV
Date: 1993
Publisher: International Union of Geological Sciences
Date: 06-2017
Publisher: Springer Science and Business Media LLC
Date: 1996
DOI: 10.1007/BF00396166
Publisher: Elsevier BV
Date: 06-1995
Publisher: Elsevier
Date: 2023
Publisher: CSIRO Publishing
Date: 2010
DOI: 10.1071/MF09066
Abstract: The recent drought in south-eastern Australia has exposed to air, large areas of acid sulfate soils within the River Murray system. Oxidation of these soils has the potential to release acidity, nutrients and metals. The present study investigated the mobilisation of these substances following the rewetting of dried soils with River Murray water. Trace metal concentrations were at background levels in most soils. During 24-h mobilisation tests, the water pH was effectively buffered to the pH of the soil. The release of nutrients was low. Metal release was rapid and the dissolved concentrations of many metals exceeded the Australian water quality guidelines (WQGs) in most tests. The concentrations of dissolved Al, Cu and Zn were often greater than 100× the WQGs and strong relationships existed between dissolved metal release and soil pH. Attenuation of dissolved metal concentrations through co-precipitation and adsorption to Al and Fe precipitates was an important process during mixing of acidic, metal-rich waters with River Murray water. The study demonstrated that the rewetting of dried acid sulfate soils may release significant quantities of metals and a high level of land and water management is required to counter the effects of such climate change events.
Publisher: International Union of Geological Sciences
Date: 06-2017
Publisher: CSIRO Publishing
Date: 2009
DOI: 10.1071/SR08244
Abstract: Digital soil mapping (DSM) offers apparent benefits over more labour-intensive and costly traditional soil survey. Large cartographic scale (e.g. 1 : 10 000 scale) soil maps are rare in Australia, especially in agricultural areas where they are needed to support detailed land evaluation and targeted land management decisions. We describe a DSM expert system using environmental correlation that applies a priori knowledge from a key area (128 ha) soil–landscape with a regionally repeating toposequence to predict the distribution of saline–sodic subsoil patterns in the surrounding upland farming region (2275 ha) in South Australia. Our predictive framework comprises interrelated and iterative steps, including: (i) consolidating a priori knowledge of the key area soil–landscape (ii) refining existing mentally held and graphic soil–landscape models (iii) selecting suitable environmental covariates compatible with geographic information systems (GIS) by interrogation via 3D visualisation using a GIS (iv) transforming the existing soil–landscape models to a computer model (v) applying the computer model to the environmental variables using the expert system (vi) performing the predictive mapping and (vii) validation. The environmental covariates selected include: digital terrain attributes of slope gradient, topographic wetness index and plan curvature, and airborne gamma-radiometric K%. We apply selected soil profile physiochemical data from a prior soil survey to validate mapping. Results showed that we correctly predicted the saline–sodic subsoils in 10 of 11 reference profiles in the region.
Publisher: Springer Science and Business Media LLC
Date: 31-07-2013
DOI: 10.1007/S10661-013-3350-9
Abstract: Large-scale exposure of acid sulfate soils during a hydrological drought in the Lower Lakes of South Australia resulted in acidification of surface water in several locations. Our aim was to describe the techniques used to monitor, assess and manage these acidification events using a field and laboratory dataset (n = 1,208) of acidic to circum-neutral pH water s les. The median pH of the acidified (pH < 6.5) s les was 3.8. Significant (p > H(+) ≈ Mn(II) > Fe(II/III)) but was about 20 % higher on average. Geochemical speciation calculations and XRD measurements indicated that solid phase minerals (schwertmannite and jarosite for Fe and jurbanite for Al) were likely controlling dissolved metal concentrations and influencing measured acidity between pH 2 and 5.
Publisher: Elsevier BV
Date: 2017
Publisher: Informa UK Limited
Date: 24-10-2017
Publisher: Elsevier BV
Date: 12-2017
Publisher: CSIRO
Date: 2020
DOI: 10.25919/TG90-3X77
Publisher: Elsevier BV
Date: 06-2014
DOI: 10.1016/J.JCONHYD.2014.03.003
Abstract: A severe drought from 2007 to 2010 resulted in the lowest river levels (1.75 m decline from average) in over 90 years of records at the end of the Murray-Darling Basin in South Australia. Due to the low river level and inability to apply irrigation, the groundwater depth on the adjacent agricultural flood plain also declined substantially (1-1.5 m) and the alluvial clay subsoils dried and cracked. Sulfidic material (pH>4, predominantly in the form of pyrite, FeS2) in these subsoils oxidised to form sulfuric material (pH<4) over an estimated 3300 ha on 13 floodplains. Much of the acidity in the deeply cracked contaminated soil layers was in available form (in pore water and on cation exchange sites), with some layers having retained acidity (iron oxyhydroxysulfate mineral jarosite). Post drought, the rapid raising of surface and ground water levels mobilised acidity in acid sulfate soil profiles to the floodplain drainage channels and this was transported back to the river via pumping. The drainage water exhibited low pH (2-5) with high soluble metal (Al, Co, Mn, Fe, Mn, Ni, and Zn) concentrations, in exceedance of guidelines for ecosystem protection. Irrigation increased the short-term transport of acidity, however loads were generally greater in the non-irrigation (winter) season when rainfall is highest (0.0026 tonnes acidity/ha/day) than in the irrigation (spring-summer) season (0.0013 tonnes acidity/ha/day). Measured reductions in groundwater acidity and increases in pH have been observed over time but severe acidification persisted in floodplain sediments and waters for over two years post-drought. Results from 2-dimensional modelling of the river-floodplain hydrological processes were consistent with field measurements during the drying phase and illustrated how the declining river levels led to floodplain acidification. A modelled management scenario demonstrated how river level stabilisation and limited irrigation could have prevented, or greatly lessened the severity of the acidification.
Publisher: Springer Science and Business Media LLC
Date: 04-2006
Publisher: Elsevier BV
Date: 10-2021
Publisher: Elsevier BV
Date: 2019
DOI: 10.1016/J.SCITOTENV.2018.07.383
Abstract: Good management of sulfide minerals and sulfuric acid in Acid Sulfate Soils (ASS) requires cost-effective rapid analytical data for their characterisation. However, the determination of properties in ASS s les using traditional laboratory techniques is expensive and time consuming. Excessive delays in analysis risks s le changes from oxidation. Mid-infrared (MIR) spectroscopy with multivariate regression offers a quicker and cheaper surrogate. This manuscript reports the prediction of some of the following key soil parameters in ASS characterisation using benchtop (Perkin Elmer) and handheld (ExoScan) diffuse reflectance MIR Fourier transform (DRIFT) spectrometers: Total Organic Carbon (TOC), Titratable Actual Acidity (TAA), Extractable Sulfate Sulfur (ESS), Reduced Inorganic Sulfur (RIS), Retained Acidity (RA), Acid Neutralising Capacity (ANC), and Lime Calculation (LC). Three sets of representative ASS soil profiles, comprising 132 s les from hyposulfidic, hypersulfidic and sulfuric materials, and covering a wide range of environments in South Australia were scanned under laboratory conditions. These were combined with reference laboratory data in partial least squares regression (PLSR) calibration models. The calibrations were validated by leave-one-out cross validation, with a further test set available for validation. Predictions with coefficient of determination (R
Publisher: Elsevier BV
Date: 03-2015
DOI: 10.1016/J.JENVMAN.2015.01.016
Abstract: Acid sulfate soils (ASS) with sulfuric material can be remediated through microbial sulfate reduction stimulated by adding organic matter (OM) and increasing the soil pH to >4.5, but the effectiveness of this treatment is influenced by soil properties. Two experiments were conducted using ASS with sulfuric material. In the first experiment with four ASS, OM (finely ground mature wheat straw) was added at 2-6% (w/w) and the pH adjusted to 5.5. After 36 weeks under flooded conditions, the concentration of reduced inorganic sulfur (RIS) and pore water pH were greater in all treatments with added OM than in the control without OM addition. The RIS concentration increased with OM addition rate. The increase in RIS concentration between 4% and 6% OM was significant but smaller than that between 2% and 4%, suggesting other factors limited sulfate reduction. In the second experiment, the effect of nitrate addition on sulfate reduction at different OM addition rates was investigated in one ASS. Organic matter was added at 2 and 4% and nitrate at 0, 100, and 200 mg nitrate-N kg(-1). After 2 weeks under flooded conditions, soil pH and the concentration of FeS measured as acid volatile sulfur (AVS) were lower with nitrate added at both OM addition rates. At a given nitrate addition rate, pH and AVS concentration were higher at 4% OM than at 2%. It can be concluded that sulfate reduction in ASS at pH 5.5 can be limited by low OM availability and high nitrate concentrations. Further, the inhibitory effect of nitrate can be overcome by high OM addition rates.
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/EA00198
Abstract: The objectives of this study were to develop a systematic approach to identify important soil morphological and vegetation field indicators to better target land management in degraded landscapes in a specific region. The authors were able to link the soil-landscape features to the main soil and water processes operating within the landscape. This information was used to develop a set of field indicators (e.g. soil colour) within a user-friendly soil classification key that is linked to land use options to form the basis of a manual. It was shown that information written in this format helped farmers and regional advisers to identify options for remediation of waterlogged and saline areas and to improve planning at property and catchment scales. The authors identified a series of steps to be taken in producing the manual. Steps 1–5 describe the soil layers and construct them in toposequences, which are then used to map soil types in key surrounding areas. Steps 6–9 involve the local community in developing the manual.The paper provides an account of how manuals have been produced for 2 badly degraded areas in southern Australia (Mount Lofty Ranges, South Australia and western Victoria) and promotes the methodologies for other regions. Descriptive soil information is pictorially integrated along toposequences and applied to identify key soil features. Complex scientific processes and terminology are more simply communicated to local groups using coloured cross-sectional diagrams and photographs of soil and vegetation to overcome some of the perceived barriers to adoption of best management practices. We consider the approach should have generic application.
Publisher: Society for Sedimentary Geology
Date: 07-2005
DOI: 10.2110/JSR.2005.060
Publisher: Wiley
Date: 1992
Publisher: Springer Science and Business Media LLC
Date: 21-08-2016
Publisher: Springer Netherlands
Date: 2013
Publisher: Springer Netherlands
Date: 2013
Publisher: CSIRO Publishing
Date: 2017
DOI: 10.1071/SR16272
Abstract: Rising saline groundwatertables and drought in the Lower Murray Reclaimed Irrigation Area (LMRIA) has created soil salinity and sodicity conditions, which has resulted in a decline in agricultural production. A 2 month field experiment was conducted at Mobilong irrigation area using a randomised block design with trial plots (4m2) in each of the three blocks containing the following six treatments: (1) control (not irrigated), (2) irrigation (River Murray water) only, (3) gypsum application (1.5 kg/m2) and irrigation, (4) limestone application (1.5 kg/m2) and irrigation, (5) seawater (source of dissolved Ca2+) application (100mm depth) and irrigation and (6) acid (pH 3) drainage (to dissolve CaCO3 in soil to release Ca2+) application (100mm irrigation water depth) and irrigation. Soil electrical conductivity (EC), pH, exchangeable cations (Ca2+, Mg2+, Na+, K+), exchangeable sodium percentage (ESP) and saturated hydraulic conductivity were measured. The decrease in EC was greatest in the irrigation only treatment followed by the gypsum and limestone treatments. At the end of the trial, the EC in the irrigation only treatment was about one-quarter of the control, in which the EC increased. The seawater and acid drainage treatments reduced the soil EC relative to the control but the EC was 2–3dS/m higher than the irrigation, gypsum and limestone treatments at the end of the trial. The gypsum, irrigation only and limestone treatments approximately doubled the exchangeable Ca relative to the control and exchangeable Na was reduced. Unsaturated water and solute transport model (HYDRUS-UNSATCHEM) simulations were able to represent the general trends in the field results. The results suggest that only River Murray water irrigation and drainage could be effective for the management of soil salinity and sodicity in the LMRIA but further research is required to establish the threshold electrolyte concentration to prevent soil dispersion.
Publisher: CSIRO Publishing
Date: 1983
DOI: 10.1071/SR9830219
Abstract: Red, yellow and grey earths consist largely of quartz, kaolin, and iron oxides and hydroxides, but little is known of the pedological processes that have resulted in their formation. Iron oxides and hydroxides, however, vary markedly according to their soil environments and can be used to study pedogenetic pathways in soil profiles. A detailed mineralogical examination has been made of two soils representing the red and grey end-members of the red-yellow-grey earth soil continuum in the semiarid tropical Torrens Creek area, 200-300 km southwest of Townsville, in central north Queensland. The profiles selected (a Plinthustalf and Haplargid of Soil Taxonomy) have high contents of ferruginous gravels in the solum, and are underlain by mottled, weathered sandstone. Four corresponding layers were s led from each soil profile. Washed gravels from these s les were sieved into four size classes, and were sorted by hand into morphological groups, and into magnetic and nonmagnetic fractions. Subs les of the resultant groups of gravels ( mm), of the fine earth ( 2 mm), and of the whole soil, were analysed by X-ray diffraction. Quartz, kaolin, goethite and hematite were found in various proportions in the 205 analysed s les, but maghemite was restricted to the magnetic materials few other minerals were detected. The mineralogical composition of each morphological group of gravels was found to be independent of the particle-size of the materials in the group. The iron oxide mineralogy of the soils suggests that the red, yellow and grey earths developed under different soil water regimes: free drainage and high organic matter oxidation rates in the red earths yielded hematite, with its strong red-pigmenting capacity, and goethite profile saturation for relatively short periods of time has resulted in the formation of goethite, characteristic of the yellow earths and of the ferruginous gravels of the grey earths and saturation of the grey earth profiles for lengthy periods has led to the loss of iron from the soil, which has then assumed the grey colour of the minerals (quartz and kaolin) comprising its matrix. These mineralogical interpretations are supported by field observations of contrasting hydrological regimes in the soils.
Publisher: IOP Publishing
Date: 11-2009
Publisher: University of Adelaide Press
Date: 20-11-2017
Publisher: CSIRO Publishing
Date: 1993
DOI: 10.1071/EA9930239
Abstract: The effect of landuse on composition of throughflow water immediately above the clayey B horizons in duplex soils (mostly natric and/or sodic) in the Mount Lofty Ranges, South Australia, was investigated using simple lysimeters. During July-November 1991, the pH of the first flow immediately after rainstorm under pines, native woodland, and pasture, respectively, was 5.7, 6.0, and 6.4. At each of the sites, average pH over 4 months during July-November was 5.8-5.9. Both the electrical conductivity (EC) and the amounts of total dissolved solids (TDS) were 2-3 times higher under pine than at other sites. The rate of change in EC with respect to TDS varied considerably among the sites, possibly due to the large differences in the concentration of dissolved organic compounds. Although the pH of water was .5, both aluminium and iron were recorded, especially under pine, where there were also high levels of dissolved organic compounds. High levels of suspended colloidal matter were recorded in the water flowing under pine, and these levels were related to dissolved organic carbon.
Publisher: Informa UK Limited
Date: 08-01-2015
Publisher: Elsevier BV
Date: 07-2017
DOI: 10.1016/J.FORSCIINT.2017.03.026
Abstract: A series of soil transference experiments (STEs) were undertaken to determine whether patterns identified in laboratory experiments could also be recognised at a simulated crime scene in the field. A clothed 55kg human rescue dummy dressed in a padded bra was either dragged or merely placed on a soil surface at sites with natural and anthropogenic soil types under both wet and dry soil conditions. Transfer patterns produced by dragging compared favourably with those of laboratory experiments. Twelve patterns were identified when a clothed human rescue dummy was dragged across the two soil types in the field. This expanded the original set of eight soil transfer patterns identified from dragging weighted fabric across soil s les in the laboratory. Soil transferred by placing the human rescue dummy resulted in a set of six transfer patterns that were different to those produced by dragging. By comparing trace soil patterns transferred to bras using each transfer method, it was revealed that certain transfer patterns on bras could indicate how the fabric had made contact with a soil surface. A photographic method was developed for crime scene examiners to capture this often subtle soil evidence before a body is transported or the clothing removed. This improved understanding of the dynamics of soil transference to bras and related clothing fabric may assist forensic investigators reconstruct the circumstances of a variety of forensic events.
Publisher: Wiley
Date: 09-1977
Publisher: CSIRO Publishing
Date: 1994
DOI: 10.1071/SR9940909
Abstract: Procedures for detailed mapping of a large number of soil features in small landscape units displayed in either vertical cross section (i.e. soil toposequences) or horizontal plane (i.e. soil maps) are presented. Rom hand coloured drawings that display the soil-landscape features, an Apple Macintosh Computer, with Adobe Illustrator and Adobe Patterns and Textures programs, is used to produce high quality coloured maps ready for reproduction in any form (e.g. posters, publications, slides or overhead transparencies). The first step is to produce the detailed computer map with all soil features included. This detailed computer map is made up of the following three layers or bases: (i) a black linework and lettering base, (ii) a polygon base filled with black and white textures, and (iii) a polygon base filled with colours. The detailed computer map, saved as the master file, is very easily modified to generate more simplified and thematic maps by: (i) grouping soil features into larger soil components in order to display soil-landscapes in a more simplified form, (ii) deleting certain soil-landscape components in order to highlight specific soil features, and (iii) adding newly aquired information (e.g. chemical and hydrological data) to previous versions.
Publisher: Elsevier BV
Date: 03-1987
Publisher: Open Access Text Pvt, Ltd.
Date: 2017
DOI: 10.15761/FSC.1000110
Publisher: CSIRO Publishing
Date: 1985
DOI: 10.1071/SR9850543
Abstract: Fifty-one s les, collected from 26 sites in New Zealand, South Africa and Australia, were tested for the presence of lepidocrocite (�-FeOOH) and goethite (�-FeOOH). The s les were predominantly orange-coloured mottles, bands, crusts and pipestems from hydromorphic soils, but also included a placic horizon, iron-rich precipitates from water courses, altered pyrite cubes, and geode-like features in weathered saprolites. The iron oxides were identified and characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Lepidocrocite was identified in 49 of the s les, and in 44 was present in concentrations exceeding I%, with the highest being approximately 70%. Crystallinities of the lepidocrocite were assessed from the widths and positions of XRD peaks, and, in some cases, from TEM. Goethite was also present in most s les, and predominated over lepidocrocite in some. In all three countries, the most common occurrence of lepidocrocite was associated with the gleyed soil materials commonly found in wet, poorly drained pseudogley soils (mostly 'humic slope gley') of humid temperate climate. Under these climatic conditions the high degree of water supply, relatively lower soil temperatures, lower evaporation and slower water movement caused reductomorphic conditions. At these sites soil iron oxides are reduced and, on reoxidation, lepidocrocite and goethite are generally formed. The colour generally associated with lepidocrocite in iron-rich segregations in hydromorphic soils is 7.5YR6-7/4-8 Lepidocrocite was also identified in all of the other s les mentioned above. A study of the relative proportions of lepidocrocite and goethite, and the crystallinity of these associated minerals in the various morphological concentrations (profile trends), suggests that their formation is strongly governed by soil microenvironmental factors (pH, Eh, and ionic environment). However, climatic and pedogenic factors such as podzolization and high organic matter contents may modify these mineral phases or induce further transformation. These findings indicate that lepidocrocite occurs in a remarkably wide range of materials and weathering environments. Moreover, the morphology, crystallinity, differential XRD line broadening and line shift of the lepidocrocite, and the commonly associated goethite also vary markedly in the respective materials. This suggests that other factors associated with particular weathering environments, such as those involved in pseudomorphous alteration of pyrite and the influence of chloride ions, may be more important in the formation of lepidocrocite than the conditons associated with hydromorphy. The morphology and characteristics of lepidocrocite and goethite, together with field associations, appear to be useful indicators of soil genesis.
Publisher: CSIRO
Date: 2010
Publisher: Elsevier BV
Date: 12-2017
Publisher: Elsevier BV
Date: 06-1982
Publisher: Elsevier BV
Date: 03-1987
Publisher: Elsevier BV
Date: 07-2014
DOI: 10.1016/J.SCITOTENV.2014.03.063
Abstract: Acid sulfate soils with sulfuric material (pH 4) underlying this former floodplain occurred due to falling river and groundwater levels during the 2006-2010 extreme "millennium" drought. A low pH ( 3 years) following a return to pre-drought water levels.
Publisher: Elsevier BV
Date: 11-2015
DOI: 10.1016/J.JHAZMAT.2015.05.013
Abstract: Sulfuric material is formed upon oxidation of sulfidic material it is extremely acidic, and therefore, an environmental hazard. One option for increasing pH of sulfuric material may be stimulation of bacterial sulfate reduction. We investigated the effects of organic carbon addition and pH increase on sulfate reduction after re-flooding in ten sulfuric materials with four treatments: control, pH increase to 5.5 (+pH), organic carbon addition with 2% w/w finely ground wheat straw (+C), and organic carbon addition and pH increase (+C+pH). After 36 weeks, in five of the ten soils, only treatment +C+pH significantly increased the concentration of reduced inorganic sulfur (RIS) compared to the control and increased the soil pore water pH compared to treatment+pH. In four other soils, pH increase or/and organic carbon addition had no significant effect on RIS concentration compared to the control. The RIS concentration in treatment +C+pH as percentage of the control was negatively correlated with soil clay content and initial nitrate concentration. The results suggest that organic carbon addition and pH increase can stimulate sulfate reduction after re-flooding, but the effectiveness of this treatment depends on soil properties.
Publisher: Elsevier BV
Date: 12-2017
Publisher: Elsevier
Date: 1993
Publisher: Elsevier BV
Date: 03-2021
Publisher: Elsevier BV
Date: 08-2009
Publisher: CSIRO Publishing
Date: 1990
DOI: 10.1071/SR9900465
Abstract: Thermoluminescence (TL) of quartz grains has been used to date a soil horizon at each of four sites in a chronosequence of freely drained podzols at Cooloola and North Stradbroke Island. The chronological order of the TL dates is in agreement with the sequence of inferred ages based on stratigraphic, geomorphic, denudational and pedological evidence, but at least one of the TL dates is of considerably greater age than the field evidence implies. Possible explanations of this anomaly are discussed. Differences in the nature of the quartz grains and the various pre-treatments used in TL dating were also examined by using a combination of thermogravimetric analysis (TGA), differential thermal analysis (DTA) and scanning electron microscopy (SEM) methods. The DTA showed no dissimilarity among the quartz s les from the different sites, but the TGA results showed significant weight losses for some s les and pretreatments. The SEM method further showed that weight loss is associated with water-sorbing substances (allophanic materials) present as coatings on grain surfaces and/or in cracks within grains.
Publisher: Wiley
Date: 03-1977
Publisher: Elsevier BV
Date: 02-2021
Publisher: Elsevier BV
Date: 10-2017
DOI: 10.1016/J.FORSCIINT.2017.08.018
Abstract: Archival research into episodes of frontier violence in the Kimberley region of Western Australia indicate that the bodies of Aboriginal victims of massacres were frequently incinerated following the event. This paper presents the results of a scientific investigation of a reported massacre at Sturt Creek where burnt bone fragments were identified in two adjacent sites and documents the archaeological signatures associated with the sites. The methodology used to undertake the project brought together three systems of knowledge: the oral testimonies of the descent group originating from a sole adult survivor of the massacre archival, historical and scientific research. An archaeological survey defined the two distinct sites containing hundreds of fragile bone fragments a third site was found to be highly disturbed. Scientific investigations included macroscopic and microscopic examination of selected bone fragments by an anatomical pathologist and a zooarchaeologist and X-ray diffraction analysis of sixteen bone fragments. The anatomical pathologist and zooarchaeologist undertook macroscopic and microscopic examinations of selected bone s les to identify morphological evidence for human origin. It was concluded that three bone fragments examined may have been human, and two of the fragments may have been from the vault of a skull. It was concluded that the likelihood of them being human would be strengthened if it was found that the three s les had been subjected to high temperatures. X-ray diffraction analysis of 16 bone fragments provided this evidence. All fragments showed sharp hydroxylapatite peaks (crystallite sizes 9882nm and 597nm respectively) and all had been subjected to extreme temperatures of either 600°C for more than 80h, 650°C for more than 20h, 700°C for more than 4h or 800°C for more than 1h. XRD analyses were also done on bone s les collected from three cooking hearths at three different archaeological sites. It was found that two of the three s les had been exposed to substantially lower temperatures for a short time period. It was concluded that there was strong pathological and archaeological evidence that the bone fragments were human in origin, but that the evidence was not conclusive. This research also identified archaeological signatures for the identification of massacre sites in similar Australian environments and circumstances.
Publisher: Elsevier BV
Date: 05-2006
Publisher: Elsevier BV
Date: 06-2020
Publisher: Springer Science and Business Media LLC
Date: 1988
Publisher: Springer Science and Business Media LLC
Date: 1978
Publisher: Geological Society of London
Date: 28-08-2019
Publisher: American Chemical Society (ACS)
Date: 04-2009
DOI: 10.1021/ES8036548
Abstract: Iron-monosulfide oxidation and associated S transformations in a natural sediment were examined by combining selective extractions, electron microscopy and S K-edge X-ray absorption near-edge structure (XANES) spectroscopy, The sediment examined in this study was collected from a waterway receiving acid-sulfate soil drainage. It contained a high acid-volatile sulfide content (1031 micromol g(-1)), reflecting an abundance of iron-monosulfide. The iron-monosulfide speciation in the initial sediment s le was dominated by nanocrystalline mackinawite (tetragonal FeS). At near-neutral pH and an 02 partial pressure of approximately 0.2 atm, the mackinawite was found to oxidize rapidly, with a half-time of 29 +/- 2 min. This oxidation rate did not differ significantly (P < 0.05) between abiotic versus biotic conditions, demonstrating that oxidation of nanocrystalline mackinawite was not microbially mediated. The extraction results suggested that elemental S (S8(0)) was a key intermediate S oxidation product Transmission electron microscopy showed the S8(0) to be amorphous nanoglobules, 100-200 nm in diameter. The quantitative importance of S8(0) was confirmed by linear combination XANES spectroscopy, after accounting for the inherent effect of the nanoscale S8(0) particle-size on the corresponding XANES spectrum. Both the selective extraction and XANES data showed that oxidation of S8(0) to SO4(2-) was mediated by microbial activity. In addition to directly revealing important S transformations, the XANES results support the accuracy of the selective extraction scheme employed here.
Publisher: Wiley
Date: 04-10-2011
Publisher: Open Access Text Pvt, Ltd.
Date: 2017
DOI: 10.15761/FSC.1000109
Publisher: Informa UK Limited
Date: 2013
Publisher: CSIRO Publishing
Date: 1994
DOI: 10.1071/SR9940889
Abstract: A pedo-hydrological method which involves interpreting features in soils that result from both ancient and modern processes along toposequences in a subcatchment of the Mt Lofty Ranges, South Australia, is used to construct conceptual soil-water-landscape models. This method links soil-landscape features to soil-water processes with strong emphasis on: (i) soil water-flow systems and (ii) soil-forming and soil-change processes. The conceptual model illustrates the interactions between soil processes acting in soil water-flow systems. This model is able to predict future modes of soil-landscape evolution under changing environmental conditions. As well, it may be used by land and water supply managers to develop more efficient management strategies under conditions of increasing land degradation (e.g. erosion and water pollution). A typical Palexeralf-Natraqualf hydro-toposequence of soils (i.e. catena consisting of red-yellow-grey duplex soils) is used as an ex le to illustrate this new approach. The landscape selected is undergoing severe soil degradation (i.e. waterlogging, dryland salinity, erosion and water pollution). The constructed conceptual soil-water-landscape model is the result of detailed pedo-hydrological investigations along toposequences in a representative subcatchment in the high rainfall zone ( mm) of the Mount Lofty Ranges, South Australia. The model illustrates in graphic form interactions between three soil water-flow systems (freely drained red soil system, hydromorphic topsoil system, hydromorphic subsoil system) and eight soil processes (saprolitization, ferralitization, glaebulization, redoximorphism, eluviation/illuviation, salinization/solonization, sulfidization/sulfuricization and water erosion). The study demonstrates that this whole ecosystem has been placed into disequilibrium thereby developing severe land degradation problems as a result of rising saline sulfatic ground watertables and perched watertables due to land-clearing since European settlement. The purpose of this paper is to provide a methodology framework and overall summary for other papers in a series dealing essentially with detailed field and laboratory investigations of in idual soil-water processes.
Publisher: Oxford University Press (OUP)
Date: 08-1999
Publisher: Wiley
Date: 2012
DOI: 10.2136/SH12-05-0016
Publisher: CSIRO Publishing
Date: 2009
DOI: 10.1071/SR07191
Abstract: We describe a soil–landscape investigation conducted in a South Australian upland hillslope (128 ha) to understand the distribution and causes of saline–sodic soil patterns using convenient, ground-based geophysical surveys of the hillslope. These surveys included: (i) EM31 for deep (~6 m) apparent electrical conductivity (ECa) patterns, (ii) EM38 for shallow ( .5 m) ECa patterns, and (iii) Bartington MS2-D loop sensor for surface volume magnetic susceptibility (κ) patterns. From these surveys we inferred hillslope distributions of: (i) deep (~6 m) concentrations of salinity associated with deep groundwater systems and deposits of magnetic gravels (dominated by maghemite and hematite) (EM31 sensor) (ii) shallow ( .5 m) soil salinity (EM38 sensor) and (iii) preservation of pedogenic magnetic materials (e.g. maghemite and hematite) (MS2-D loop sensor). We also describe terrain analysis to locate near-surface hydropedological patterns using topographic wetness index. When combined in 3D geographic information system, strong visual matches were identified between patterns in: (i) geophysical surveys, (ii) terrain, and (iii) soil survey data, thus allowing integrated interpretations of soil–landscape pedogenic processes to be made on a whole-of-landscape basis. Such mechanistic interpretations of soil–landscape processes reveal and map intricate saline and sodic soil–regolith patterns and groundwater and fresh surface water flow paths that were not revealed during a previous traditional soil survey.
Publisher: Wiley
Date: 24-05-2013
DOI: 10.1111/SUM.12051
Publisher: CSIRO Publishing
Date: 1992
DOI: 10.1071/SR9920615
Abstract: Distribution of total elemental C, Al, Si, Fe, Mn, P, Ti and Zr in a chronosequence of podzols spanning some 7x105 years is presented. Considerable variation in elemental composition occurred down each profile due to translocation and nonuniform banding of heavy mineral concentrations. The mobility and fate of these elements and Cr were determined by extractions with sodium pyrophosphate, ammonium oxalate (pH 3.0), dithionitelcitrate and dilute HCl. In some cases, pyrophosphate extractions gave higher values than expected when considering the ammonium oxalate values, confirming that peptization can occur with the former. Extraction data demonstrate that all elements with the exception of Mn and Zr have been mobilized from the A horizon and accumulated in the B horizon. Mn is lost from the A horizons but there is no evidence for accumulation elsewhere in the profiles, while there is no evidence for the movement or accumulation of Zr. As the profiles develop and the thickness of the A horizons increases, Al accumulates as Al-organic matter complexes in the Bh and Bhs horizons and as proto-imogolite allophane, determined by 29Si n.m.r. spectroscopy, in the Bhs and Bs horizons. Selective dissolution by using oxalate and dithionitelcitrate demonstrates accumulation of proto-imogolite in the Bhs and Bs horizons with age, and also suggests that its nature may vary within profiles. In most profiles, only a small proportion of P is extracted by oxalate or dithionitelcitrate and appears to be in the form of monazite and gorceixite. Across the chronosequence, P accumulates in the lower B horizons and is associated with Al-organic matter complexes and proto-imogolite. Iron accumulates in B horizons and, as the later stages of podzol development, such as the giant pipey podzols, are reached, many of the lower horizons contain % of Fe as secondary Fe oxyhydroxides. Most of the secondary Fe in the Bh and Bhs horizons is present as Al substituted goethite while, in the Bs horizons and below, ferrihydrite is the dominant mineral. There is little evidence for significant concentrations of Fe-organic matter complexes. Fe maxima occur above the Al maxima in the younger profiles and below it in the older ones. Fe is progressively lost during profile development and is depleted from humus podzols which are often the final stage of podzol genesis. Titanium is the most abundant element after Si. Extraction data strongly suggest that Ti is largely present in primary minerals such as ilmenite, rutilelanatase and pseudorutile. Evidence is presented for the presence of Ti-organic matter complexes in A horizons and Ti mobilized in this form appears to result in the formation of pedogenic anatase or rutile in the upper B horizons. The selective dissolution data for Ti and Fe suggest possible Ti-substitution for iron in goethites which appears to be common in B horizons of the freely drained profiles, although little Ti is associated with ferrihydrite.
Publisher: Informa UK Limited
Date: 03-1981
Publisher: Informa UK Limited
Date: 1992
Publisher: University of Adelaide
Date: 2019
Publisher: Mineralogical Society
Date: 12-2017
Publisher: University of Adelaide Press
Date: 12-2018
Publisher: Geological Society of London
Date: 2021
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/EA01012
Abstract: During the last decade, a range of indicators has been advocated for assessing soil, farm and catchment health. This paper assembles some recent experiences of the authors in developing and using indicators from paddock to national scales. Indicators are merely a subset of the attributes that are used to quantify aspects of catchment or farm health. Their selection and use in the past has led to criticism of indicators, but, given an explicit approach, most of the criticisms can be overcome. Reliable indicators provide positive and negative signals about the current status of natural resources and how these properties have changed over time. They are used both to identify potential risks and to confirm that current farming practices and systems of land use are effective in maintaining the resource base or economic status. They should be precursors for change and future on-ground investments when problems are observed or identified.A structured approach is needed to ensure indicators are selected and used efficiently. This approach involves: deciding local issues and selecting the most appropriate indicators to reflect those issues interpreting both positive and negative signals from the monitoring process taking appropriate action to resolve problems and, using indicators to monitor the outcomes from the action taken.Finally, we have drawn on these and other experiences to compile a list of indicators that may be used to address sustainability issues associated with farm productivity, soil health and catchment health identified in recent strategic plans developed for the northern grains region of Australia, the focus of this special journal issue.
Publisher: Informa UK Limited
Date: 02-2011
Publisher: Wiley
Date: 10-04-2014
DOI: 10.1111/SUM.12108
Publisher: Elsevier BV
Date: 11-2020
Publisher: Elsevier BV
Date: 2016
Publisher: Elsevier BV
Date: 06-2021
Publisher: Emerald
Date: 14-10-2013
Abstract: – The purpose of this paper is to present a theoretical overview of the field of knowledge transfer and educational change and a discussion of the issues raised in the six papers in this special edition. – A theoretical analysis of the field of knowledge transfer. – The six papers consider issues such as the interplay of ideas between British and Indian educationalists, post-war debates over literacy standards, the use of curriculum materials for the process of citizen formation, the influence of international exchanges in the education of adolescents for citizenship, Vigotsky and the transfer of knowledge across time, space, culture, disciplines and networks, and the way constructions of Chinese identity within history books were shaped by knowledge processes that transcended nation states. – This special issue of the History of Education Review engages with new approaches that have become available to historians in the past decade illustrating how they might be applied for the first time to key issues in the history of education across colonial and state borders. It addresses questions about the movement of knowledge across national and cultural boundaries, and examines key problems facing educators in a range of colonial and postcolonial contexts.
Publisher: Wiley
Date: 03-1984
Publisher: Elsevier BV
Date: 06-2022
Publisher: Elsevier BV
Date: 06-2015
Publisher: CSIRO Publishing
Date: 1994
DOI: 10.1071/SR9941069
Abstract: Australia has the highest ratio of salt-affected soils in relation to total surface area of any continent in the world, with approximately one third of the land mass being covered by sodic soils and 5% affected by soil salinity. Sodicity often coincides with the distribution of duplex soil profiles. In many areas these duplex soils are under agriculture. Sodicity substantially limits agricultural productivity. Although sodicity is considered to be an intrinsic property of the clay fraction of an affected profile, its full impact may be revealed through interactions with hydrological processes, resulting in various forms of both on-site and off-site environmental degradation. Some of the concepts, criteria and properties used to diagnose and classify sodic soils are discussed as a prelude to reviewing the nature and causes of the complex interactions which exist between related environmental problems such as dryland salinity, water erosion, waterlogging and water quality. There is a need for detailed studies to evaluate more thoroughly pertinent soil variables which link sodicity to both current and future environmental hazards, so that appropriate management strategies can be formulated.
Publisher: Springer Science and Business Media LLC
Date: 12-2005
Publisher: MDPI AG
Date: 10-01-2018
DOI: 10.3390/W10010055
Publisher: Wiley
Date: 05-2015
Abstract: Following the break of a severe drought in the Murray-Darling Basin, rising water levels restored subaqueous conditions to dried inland acid sulfate soils with sulfuric horizons (pH <3.5). Equilibrium dialysis membrane s lers were used to investigate in situ changes to soil acidity and abundance of metals and metalloids following the first 24 mo of restored subaqueous conditions. The rewetted sulfuric horizons remained severely acidified (pH ∼4) or had retained acidity with jarosite visibly present after 5 mo of continuous subaqueous conditions. A further 19 mo of subaqueous conditions resulted in only small additional increases in pH (∼0.5-1 pH units), with the largest increases occurring within the uppermost 10 cm of the soil profile. Substantial decreases in concentrations of some metal(loid)s were observed with time most likely owing to lower solubility and sorption as a consequence of the increase in pH. In deeper parts of the profiles, porewater remained strongly buffered at low pH values (pH <4.5) and experienced little progression toward anoxic circumneutral pH conditions over the 24 mo of subaqueous conditions. It is proposed that low pH conditions inhibited the activity of SO-reducing bacteria and, in turn, the in situ generation of alkalinity through pyrite production. The limited supply of alkalinity in freshwater systems and the initial highly buffered low pH conditions were also thought to be slowing recovery. The timescales involved for a sulfuric horizon rewetted by a freshwater body to recover from acidic conditions could therefore be in the order of several years.
Publisher: Elsevier
Date: 2013
Publisher: Elsevier BV
Date: 08-2019
Publisher: Geological Society of London
Date: 2021
DOI: 10.1144/SP492
Publisher: CSIRO
Date: 2020
DOI: 10.25919/7GN1-4H98
Publisher: Unpublished
Date: 2015
Publisher: Elsevier BV
Date: 11-2014
Publisher: Wiley
Date: 03-12-2015
DOI: 10.1111/SUM.12239
Publisher: Elsevier BV
Date: 10-2015
Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.FORSCIINT.2015.10.009
Abstract: In a recent Australian homicide, trace soil on the victim's clothing suggested she was initially attacked in her front yard and not the park where her body was buried. However the important issue that emerged during the trial was how soil was transferred to her clothing. This became the catalyst for designing a range of soil transference experiments (STEs) to study, recognise and classify soil patterns transferred onto fabric when a body is dragged across a soil surface. Soil deposits of interest in this murder were on the victim's bra and this paper reports the results of anthropogenic soil transfer to bra-cups and straps caused by dragging. Transfer patterns were recorded by digital photography and photomicroscopy. Eight soil transfer patterns on fabric, specific to dragging as the transfer method, appeared consistently throughout the STEs. The distinctive soil patterns were largely dependent on a wide range of soil features that were measured and identified for each soil tested using X-ray Diffraction and Non-Dispersive Infra-Red analysis. Digital photographs of soil transfer patterns on fabric were analysed using image processing software to provide a soil object-oriented classification of all soil objects with a diameter of 2 pixels and above transferred. Although soil transfer patterns were easily identifiable by naked-eye alone, image processing software provided objective numerical data to support this traditional (but subjective) interpretation. Image software soil colour analysis assigned a range of Munsell colours to identify and compare trace soil on fabric to other trace soil evidence from the same location without requiring a spectrophotometer. Trace soil from the same location was identified by linking soils with similar dominant and sub-dominant Munsell colour peaks. Image processing numerical data on the quantity of soil transferred to fabric, enabled a relationship to be discovered between soil type, clay mineralogy (smectite), particle size and soil moisture content that would not have been possible otherwise. Soil type (e.g. Anthropogenic, gravelly sandy loam soil or Natural, organic-rich soil), clay mineralogy (smectite) and soil moisture content were the greatest influencing factors in all the dragging soil transference tests (both naked eye and measured properties) to explain the eight categories of soil transference patterns recorded. This study was intended to develop a method for dragging soil transference laboratory experiments and create a baseline of preliminary soil type roperty knowledge. Results confirm the need to better understand soil behaviour and properties of clothing fabrics by further testing of a wider range of soil types and clay mineral properties.
Publisher: Geological Society of London
Date: 28-08-2021
Publisher: Elsevier BV
Date: 09-2015
Publisher: CSIRO Publishing
Date: 1993
DOI: 10.1071/SR9930911
Abstract: The current knowledge of the nature and distribution of sodic soils in South Australia is reviewed. The agriculturally developed area of South Australia lies south of latitude 32-degrees-S. and is mainly used for low intensity grazing and dry land cereal/sheep production. A high proportion of the State, including much of the high rainfall area, has soils which are sodic ( % ESP) through a significant proportion of the profile but information on the precise nature of sodicity in these soils is limited. Where exchangeable cation data axe available, the analytical techniques used often did not precisely delineate between soluble salts in the soil and ions on exchange sites. Therefore, many of the datasets have major weaknesses and may be unreliable. Since many soils with ESP also show dispersive characteristics typical of sodic soils, there is an urgent need for new sodicity studies relating to distribution and the criteria (ESP) used to identify dispersive soils. Information on the effect of sodicity on nutrient requirements of plants, especially the modern varieties, is scarce both locally and internationally, making development of management strategies for economically sustainable crop production difficult. Further, many different grades of gypsum are available in South Australia. Preliminary studies show the presence of impurities drastically influences gypsum dissolution characteristics. More effort is needed to assess the quality and reactivity of South Australian gypsum. Some effort has been directed by land managers towards reclamation and management of sodic soils by using both gypsum and lime either separately or as mixtures. However, there is neither a scientific basis for the application of gypsum-lime mixtures nor crop production data to support such management strategies.
Publisher: Elsevier BV
Date: 02-2014
Publisher: Wiley
Date: 25-02-2020
Publisher: Springer Netherlands
Date: 2009
Publisher: American Association for the Advancement of Science (AAAS)
Date: 20-03-2020
Abstract: The cerebral cortex underlies our complex cognitive capabilities. Variations in human cortical surface area and thickness are associated with neurological, psychological, and behavioral traits and can be measured in vivo by magnetic resonance imaging (MRI). Studies in model organisms have identified genes that influence cortical structure, but little is known about common genetic variants that affect human cortical structure. To identify genetic variants associated with human cortical structure at both global and regional levels, we conducted a genome-wide association meta-analysis of brain MRI data from 51,665 in iduals across 60 cohorts. We analyzed the surface area and average thickness of the whole cortex and 34 cortical regions with known functional specializations. We identified 369 nominally genome-wide significant loci ( P 5 × 10 −8 ) associated with cortical structure in a discovery s le of 33,992 participants of European ancestry. Of the 360 loci for which replication data were available, 241 loci influencing surface area and 66 influencing thickness remained significant after replication, with 237 loci passing multiple testing correction ( P 8.3 × 10 −10 187 influencing surface area and 50 influencing thickness). Common genetic variants explained 34% (SE = 3%) of the variation in total surface area and 26% (SE = 2%) in average thickness surface area and thickness showed a negative genetic correlation ( r G = −0.32, SE = 0.05, P = 6.5 × 10 −12 ), which suggests that genetic influences have opposing effects on surface area and thickness. Bioinformatic analyses showed that total surface area is influenced by genetic variants that alter gene regulatory activity in neural progenitor cells during fetal development. By contrast, average thickness is influenced by active regulatory elements in adult brain s les, which may reflect processes that occur after mid-fetal development, such as myelination, branching, or pruning. When considered together, these results support the radial unit hypothesis that different developmental mechanisms promote surface area expansion and increases in thickness. To identify specific genetic influences on in idual cortical regions, we controlled for global measures (total surface area or average thickness) in the regional analyses. After multiple testing correction, we identified 175 loci that influence regional surface area and 46 that influence regional thickness. Loci that affect regional surface area cluster near genes involved in the Wnt signaling pathway, which is known to influence areal identity. We observed significant positive genetic correlations and evidence of bidirectional causation of total surface area with both general cognitive functioning and educational attainment. We found additional positive genetic correlations between total surface area and Parkinson’s disease but did not find evidence of causation. Negative genetic correlations were evident between total surface area and insomnia, attention deficit hyperactivity disorder, depressive symptoms, major depressive disorder, and neuroticism. This large-scale collaborative work enhances our understanding of the genetic architecture of the human cerebral cortex and its regional patterning. The highly polygenic architecture of the cortex suggests that distinct genes are involved in the development of specific cortical areas. Moreover, we find evidence that brain structure is a key phenotype along the causal pathway that leads from genetic variation to differences in general cognitive function. ( A ) Measurement of cortical surface area and thickness from MRI. ( B ) Genomic locations of common genetic variants that influence global and regional cortical structure. ( C ) Our results support the radial unit hypothesis that the expansion of cortical surface area is driven by proliferating neural progenitor cells. ( D ) Cortical surface area shows genetic correlation with psychiatric and cognitive traits. Error bars indicate SE. IMAGE CREDITS: (A) K. COURTNEY (C) M. R. GLASS
Publisher: Elsevier BV
Date: 02-1991
Publisher: Elsevier BV
Date: 12-2017
Publisher: Springer Science and Business Media LLC
Date: 10-09-2016
DOI: 10.1007/S11356-016-7597-X
Abstract: When previously oxidised acid sulphate soils are leached, they can release large amounts of protons and metals, which threaten the surrounding environment. To minimise the impact of the acidic leachate, protons and metals have to be retained before the drainage water reaches surrounding waterways. One possible amelioration strategy is to pass drainage water through permeable reactive barriers. The suitability of organic materials for such barriers was tested. Eight organic materials including two plant residues, compost and five biochars differing in feedstock and production temperature were finely ground and filled into PVC cores at 3.5 g dry wt/core. Field-collected acidic drainage water (pH 3, Al 22 mg L
Publisher: CSIRO
Date: 2010
Publisher: Elsevier BV
Date: 08-2018
DOI: 10.1016/J.TALANTA.2018.04.074
Abstract: pH is a "master variable" controlling many biogeochemical processes in soils. Acid sulfate soils undergo rapid and large pH changes from circumneutral pH under anaerobic soil conditions to sulfuric soils with ultra (pH < 3.5) and extremely (pH 3.5-4.4) acidic properties following oxidation. Measuring soil pH using a glass electrode has several potential drawbacks including liquid junction errors, drift, suspension effects and clogging. Spectrophotometric pH measurement, involving addition of an indicator dye to the s le, is widely used in seawater and has recently been developed for soil extracts at circumneutral pH ranges. The aim of this study was to extend the spectrophotometric method for application in ultra and extremely acidic soils. The acid dissociation constant (pK
Publisher: Elsevier BV
Date: 08-2022
Publisher: Elsevier BV
Date: 2022
Publisher: Springer Science and Business Media LLC
Date: 2001
Location: Australia
Location: Australia
No related grants have been discovered for Robert Fitzpatrick.