The significance and lag-time of deep through flow: an example from a small, ephemeral catchment with contrasting soil types in the Adelaide Hills, South Australia

The importance of deep throughflow in a small (3.4 km2) ephemeral catchment in the Adelaide Hills of South Australia was investigated by detailed hydrochemical analysis of soil water and stream flow during autumn and early winter rains. In this Mediterranean climate with strong summer moisture deficits, several significant rainfalls are required to generate soil throughflow and stream flow (in ephemeral streams). During Autumn 2007, a large (127 mm) drought-breaking rain occurred in April followed by significant May rains; most of this precipitation occurred prior to the initiation of stream flow in late May. These early events, especially the 127 mm event, had low (depleted) stable water isotope values compared with both later rains and average winter precipitation. Thus, this large depleted early rain event provided an excellent natural tracer. During the June and July rainfall events, daily stream and soil water samples were collected and analysed. Results from major and trace elements, water isotopes (δ18O, δD), and dissolved organic carbon analysis clearly demonstrate that a large component of this early April and May rain was stored and later pushed out of deep soil or regolith zones. This pre-event water was identified in the stream as well as identified in deeper soil horizons due to its different isotopic signature which contrasted sharply with the June–July event water. Based on this data, the regolith and throughflow system for this catchment has been re-thought. The catchment area consists of about half sandy and half clayey soils. Regolith flow is now thought to be dominated by the sandy soil system not the clayey soil system. The clayey duplex soils had rapid response to rain events and saturation excess overland flow. The sandy soils had delayed soil throughflow and infiltration excess overland flow. A pulse of macropore throughflow was observed in the sandy soils three days after the rainfall event largely ended. The macropore water was a mixture of pre-event and event water, demonstrating the lag-time and mixing of the water masses in the sandy soil system. By contrast, the clayey soil horizons were dominated by pre-event water to a much lesser degree, demonstrating the quicker response and shallow flow through of the clayey soil system. Thus, the sandy terrain has a greater vadose zone storage and greater lag time of through-flow than the clayey terrain.E. Bestland, S. Milgate, D. Chittleborough, J. VanLeeuwen, M. Pichler and L. Solonink

The Late Eocene 187Os / 188Os excursion : chemostratigraphy, cosmic dust flux and the early Oligocene glaciation

Author Posting. © The Authors, 2005. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Earth and Planetary Science Letters 241 (2006): 477-492, doi:10.1016/j.epsl.2005.11.035.High resolution records (ca. 100 kyr) of Os isotope composition (187Os/188Os) in bulk sediments from two tropical Pacific sites (ODP Sites 1218 and 1219) capture the complete Late Eocene 187Os/188Os excursion and confirm that the Late Eocene 187Os/188Os minimum, earlier reported by Ravizza and Peucker-Ehrenbrink [Earth Planet. Sci. Lett. 210 (2003) 151-165], is a global feature. Using the astronomically tuned age models available for these sites, it is suggested that the Late Eocene 187Os/188Os minimum can be placed at 34.5±0.1 Ma in the marine records. In addition, two other distinct features of the 187Os/188Os excursion that are correlatable among sections are proposed as chemostratigraphic markers which can serve as age control points with a precision of ca. ±0.1 Myr. We propose a speculative hypothesis that higher cosmic dust flux in the Late Eocene may have contributed to global cooling and early Oligocene glaciation (Oi-1) by supplying bio-essential trace elements to the oceans and thereby resulting in higher ocean productivity, enhanced burial of organic carbon and draw down of atmospheric CO2. To determine if the hypothesis that enhanced cosmic dust flux in the Late Eocene was a cause for the 187Os/188Os excursion can be tested by using the paired bulk sediment and leachate Os isotope composition, 187Os/188Os were also measured in sediment leachates. Results of analyses of leachates are inconsistent between the south Atlantic and the Pacific sites, and therefore do not yield a robust test of this hypothesis. Comparison of 187Os/188Os records with high resolution benthic foraminiferal δ18O records across the Eocene-Oligocene transition suggests that 187Os flux to the oceans decreased during cooling and ice growth leading to the Oi-1 glaciation, whereas subsequent decay of ice-sheets and deglacial weathering drove seawater 187Os/188Os to higher values. Although the precise timing and magnitude of these changes in weathering fluxes and their effects on the marine 187Os/188Os records are obscured by recovery from the Late Eocene 187Os/188Os excursion, evidence of the global influence of glaciation on supply of Os to the ocean is robust as it has now been documented in both Pacific and Atlantic records.This study was supported by NSF awards OCE-0118380, EAR-0215297 and EAR-0215297

A Controlled Experiment Utilizing Group Counseling in Four Secondary Schools in the Milwaukee Public Schools

This paper represents an experimental attempt to assess a group counseling approach; it has as background a humanistic value on the part of the writer to actually implement a goal in a three dimensional setting. The goal is to work with students who do not fit within the framework of the school. The three-dimensional setting is for four public secondary schools. Specifically, the paper asks questions. The first question deals with whether or not a group counseling approach can be utilized in working with students who demonstrate hostile acting out behavior. The paper is also addressed to the question as to whether or not a group counseling approach can be effective. A partial answer has been provided by the objective data. The feelings and opinions of the participants are equally as, or more important an answer. Therefore, in assessing the value of this study, importance has been placed on both the data and the subjective opinions which emanated from the study

A CONTROLLED EXPERIMENT UTILIZING GROUP COUNSELING IN FOUR SECONDARY SCHOOLS IN THE MILWAUKEE PUBLIC SCHOOLS

This paper represents an experimental attempt to assess a group counseling approach; it has as background a humanistic value on the part of the writer to actually implement a goal in a three dimensional setting. The goal is to work with students who do not fit within the framework of the school. The three-dimensional setting is for four public secondary schools. Specifically, the paper asks questions. The first question deals with whether or not a group counseling approach can be utilized in working with students who demonstrate hostile acting out behavior. The paper is also addressed to the question as to whether or not a group counseling approach can be effective. A partial answer has been provided by the objective data. The feelings and opinions of the participants are equally as, or more important an answer. Therefore, in assessing the value of this study, importance has been placed on both the data and the subjective opinions which emanated from the study

Catchment-scale denudation and chemical erosion rates determined from (10)Be and mass balance geochemistry (Mt. Lofty Ranges of South Australia)

Abstract not availableErick A. Bestland, CaterinaLiccioli, Lesja Soloninka, David J.Chittleborough, David Fin

Laboratory assessment of factors affecting soil clogging of soil aquifer treatment systems

In this study the effect of soil type, level of pre-treatment, ponding depth, temperature and sunlight on clogging of soil aquifer treatment (SAT) systems was evaluated over an eight week duration in constant temperature and glasshouse environments. Of the two soil types tested, the more permeable sand media clogged more than the loam, but still retained an order of magnitude higher absolute permeability. A 6- to 8-fold difference in hydraulic loading rates was observed between the four source water types tested (one potable water and three recycled waters), with improved water quality resulting in significantly higher infiltration. Infiltration rates for ponding depths of 30 cm and 50 cm were higher than 10 cm, although for 50 cm clogging rates were higher due to greater compaction of the clogging layer. Overall, physical clogging was more significant than other forms of clogging. Microbial clogging becomes increasingly important when the particulate concentrations in the source waters are reduced through pre-treatment and for finer textured soils due to the higher specific surface area of the media. Clogging by gas binding took place in the glasshouse but not in the lab, and mechanical clogging associated with particle rearrangement was evident in the sand media but not in the loam. These results offer insight into the soil, water quality and operating conditions needed to achieve viable SAT systems

Late Pleistocene Environmental Change Interpreted from δ\u3csup\u3e13\u3c/sup\u3eC and δ\u3csup\u3e18\u3c/sup\u3eO of Tooth Enamel from the Black Creek Swamp Megafauna Site, Kangaroo Island, South Australia

Stable carbon and oxygen isotope ratios of tooth enamel carbonate were collected from both fossils (50–100 ka) Tammar Wallaby (Macropus eugeneii) and Western Grey Kangaroo (Macropus fuliginosus) from a Late Pleistocene fossil deposit situated on Kangaroo Island, South Australia. δ13C and δ18O data were also obtained for modern equivalents of both species located proximal to the excavation site. Trace element compositions were collected for Sr, Ba, V, Cu, Zr, Y, La, Ca, Nd, and U for modern and fossil teeth, and for local soils. δ13C data for fossil kangaroo and wallaby range between − 5.0 and − 18‰, while less 13C enriched values between − 18 and − 25‰ are observed in modern tooth enamel. Early-formed molars are 13C depleted by 2.5‰ compared to late-formed molars, consistent with isotopic offsets observed in modern molars, and with offsets observed from preservation of original biogenic compositions. Overall, carbon isotopes indicate a shift in diet and environmental conditions from C4-inclusive mixed habitats (woods and open grasslands) during the Late Pleistocene, to C3-only wooded and closed canopy habitats today. δ18O values range between 23 and 30‰ and are indistinguishable for fossil and modern tooth enamel. Oxygen isotope compositions of plants and mammals correlate positively with local water compositions, and negatively with relative humidity. Thus, the lack of oxygen isotope differences for the Late Pleistocene vs. modern day teeth may be attributed to combined lower temperatures (decreasing local water δ18O) plus decreased relative humidity (increasing plant and mammal δ18O) in the Late Pleistocene. Trace element data from fossil and modern teeth and from fossil deposit sedimentary material indicate post burial chemical alteration. Excepting Ba and possibly Cu, concentrations of all other elements analysed (Sr, V, Zr, Y, La, Ce, Nd, and U) increased significantly relative to modern teeth (over an order of magnitude shift, with p ≤ 0.01 for t-tests and Mann–Whitney tests). This diagenetic process may have occurred during the Last Glacial Maximum (LGM), a period of localised wet conditions when significant amounts of soluble soil organic matter accumulated at the fossil site. Trace element analysis of local soils indicates that, relative to soils, teeth strongly prefer Sr and U [KD(fossil tooth/soil) 10], and exclude Zr, Cu, and possibly V and Ba [KD ≤ 0.5]. Surprisingly, Rare Earth Elements (REEs) indicate KD values of 1. These data imply that Ba is a poor indicator of chemical alteration, while Sr, U, Zr, V, Y, and REEs are particularly sensitive to alteration. Comparisons with other palaeoclimate data suggest that the environmental change on Kangaroo Island from Late Pleistocene to present was greater than on the Nullarbor Plain

Characterization of dissolved organic matter for prediction of trihalomethane formation potential in surface and sub-surface waters

Available online 15 January 2016Abstract not availableJohn Awad, John van Leeuwen, Christopher Chow, Mary Drikas, Ronald J. Smernik, David J. Chittleborough, Erick Bestlan

The effect of vegetation and soil texture on the nature of organics in runoff from a catchment supplying water for domestic consumption

Available online 22 May 2015Abstract not availableJohn Awad, John van Leeuwen, Dawit Abate, Markus Pichler, Erick Bestland, David J. Chittleborough, Nigel Fleming, Jonathan Cohen, Joel Liffner, Mary Drika

Late Pleistocene megafauna site at Black Creek Swamp, Flinders Chase National Park, Kangaroo Island, South Australia

The occurrence of fossil vertebrate remains at Black Creek Swamp at the western end of Kangaroo Island, South Australia, along with reports of 'primitive' stone implements in the vicinity has, for more than seventy years, fuelled speculation that this site would reveal a definitive relationship between humans and megafauna. Radiocarbon dating in the 1970s and again in 2004 suggested accumulation at around the last glacial maximum, making it potentially the youngest megafaunal deposit in Australia. Our excavations produced no artefacts and no evidence of butchering. Taphonomic evidence indicates three phases of drought accumulation around an ephemeral water source. These droughts may have been induced by climate, sinkhole drainage, or both. The fauna includes 29 species; one third of the species are extinct. This component is represented by browsing herbivores and their putative predator, Thylacoleo carnifex. The extant species indicate a mosaic of habitats including open sclerophyll forest, grassy patches, areas of shrubby understorey and semi-permanent water sources. The occurrence of two dwarfed species is suggestive of isolation and resource depletion. Multiple dating techniques (OSL, ESR, U-series and14C) revealed a complex geochemical history for this site. New age estimates place the fossil accumulation between 110 and 45 ka