Central South Australia Research Articles

Extending the record of lacustrine phases beyond the last interglacial for Lake Eyre in central Australia using luminescence dating

We show with multiple luminescence dating techniques that the sedimentary record for Lake Eyre, Australia's largest lake, extends beyond 200 thousand years (ka) to Marine Isotope Stage (MIS) 7. Transgressive clayey sand and finely laminated clays overlying the Miocene Etadunna Formation in Lake Eyre North document the deep-lake phases of central South Australia in the past. Until now, unresolved chronology has hampered our ability to interpret these sedimentary records, which are important for understanding the timing of the wettest phase of central Australia's late Quaternary climate. In this study, we apply quartz optically stimulated luminescence (OSL) dating, thermally-transferred OSL (TT-OSL) dating and K-feldspar post infrared infrared stimulated luminescence (pIRIR) dating to lake-floor sediments near Williams Point in Madigan Gulf to provide new age constraint for the lacustrine sediments of Lake Eyre. Methodological studies on quartz and K-feldspar demonstrate that these luminescence dating procedures are suitable for the Lake Eyre lacustrine samples and produce consistent replicate ages. A Bayesian model applied to the new dating results provides a chronological model of lacustrine deposition and shows that the transgressive clayey sand were deposited 221 ± 19 ka to 201 ± 10 ka and that the deep-water sediments were laid down in early MIS 6 (191 ± 9 ka to 181 ± 9 ka). We also find evidence for a potential depositional hiatus in mid MIS 6 and the likely formation of a palaeo-playa later in MIS 6 from 158 ± 11 ka to 143 ± 15 ka. In contrast, the MIS 5 sediments are characterised by oscillating deep- and shallow-water lacustrine units deposited 130 ± 16 ka to 113 ± 20 ka. This study is the first of its kind to provide evidence for a wet desert interior in Australia beyond the last glacial cycle using comprehensive numerical dating. Our results show that past deep-lake episodes of central South Australia, which were previously thought to represent peak interglacial conditions, are actually associated with both warm interglacial and cold glacial periods, with all the wettest episodes generally coinciding with the intervening periods between the glacial and interglacial maximums. We assume from these results that orbital forcing is not a first order control for the long-term dynamics of the Lake Eyre basin and the Indo-Australian monsoon. The high lake-level events of Lake Eyre are well correlated with millennial-scale cooling events and stadials of the North Atlantic, and coincide with weakened episodes/events for the East Asia summer monsoon. This may imply an important role for the northern high latitudes in influencing the Indo-Australian monsoon, which may be associated with a southward migration of the Intertropical Convergence Zone (ITCZ) during cooling periods in the North Atlantic.

Recent mantle degassing recorded by carbonic spring deposits along sinistral strike-slip faults, south-central Australia

The interior of the Australian continent shows evidence for late Quaternary to Recent fault-controlled mantle 3He and CO2 degassing. A series of interconnected NW-striking sinistral faults, the Norwest fault zone (NFZ), in south-central Australia are associated with travertine mounds, the latter show a regular spacing of 50–70 km. U-series ages on 26 samples range from 354±7 to 1.19±0.02ka (2σ errors) and suggest a clustering every ∼3–4 ka since ∼26 ka. Geochemical data demonstrate a remarkable mantle-to-groundwater connection. Isotopic data indicate that the groundwater is circulating to depths >3 km and interacting with Neoproterozoic/Cambrian basement and mantle volatiles. 3He/4He isotope ratios show that the He comes in part from the mantle. This demonstrates that the NFZ cuts through the entire crust and provides pathways for mantle degassing. Scaling relationships suggest that the series of sinistral faults that make up the NFZ are interconnected at depths and have a significant strike length of 60–70 km or more. The NFZ occurs where a major compositional boundary and a significant heat flow anomaly occurs, and a major step in lithospheric thickness has been mapped. We discuss a tectonic model in which recent stress field, heat flow and lithospheric structure in central Australia reactivated a set of steeply dipping Neoproterozoic faults, which may now be growing into a crustal/lithospheric-scale structure.

Calibrating δ18O in Dromaius novaehollandiae (emu) eggshell calcite as a paleo-aridity proxy for the Quaternary of Australia

The large, flightless Australian bird, Dromaius novaehollandiae (emu), breeds at about the same time of year throughout its range, and fragments of its eggshells are commonly preserved in geological and archaeological archives spanning the Late Quaternary. The δ18O of eggshell calcite is set primarily by the δ18O of body water in the days prior to egg calcification. Changes in the δ18O of body water are dominantly determined by the δ18O of ingested water. We provide a calibration dataset of 334 δ18O analyses on late Holocene Dromaius eggshell from 21 sites across a wide range of environmental conditions and climate states. In regions where interannual rainfall variability is high, the average of 20 samples from different years is required to derive a δ18O estimate within ±1‰ of the millennial mean; fewer than 10 different-year samples is sufficient for less variable rainfall regions. Many climate variables in Australia are highly correlated with δ18O in eggshell, but the strongest correlation is with the average site-specific point-potential evapotranspiration (PPET) for February plus March, two summer months prior to egg calcification, which explains 93% of the variance in the mean δ18O of our calibration dataset. Eggshell δ18O can be used as a PPET (paleo-aridity) proxy in older samples providing four assumptions are closely approximated: (1) no difference in season of breeding over time, (2) breeding in most years, (3) little change in δ18O of precipitation over time, and (4) the bird’s source water is exposed to evaporative processes. The reconstructed PPET derived from 150 δ18O measurements in an 80ka time-series of eggshell from south-central Australia where these assumptions are satisfied is consistent with independent estimates of environmental water balance derived from changes in lake level and dustiness. The tight correlation between eggshell δ18O and PPET indicates that the average δ18O in time-series of Dromaius eggshell is a robust proxy to reconstruct changes in moisture balance through the Late Quaternary of Australia.

Three terrestrial Pleistocene coucals (Centropus: Cuculidae) from southern Australia: biogeographical and ecological significance

Coucals are large, predatory, primarily ground-dwelling cuckoos of the genus Centropus, with 26 extant species ranging from Africa to Australia. Their evolutionary and biogeographical history are poorly understood and their fossil record almost non-existent. Only one species (Centropus phasianinus) currently inhabits Australia, but there is now fossil evidence for at least three Pleistocene species. One of these (Centropus colossus) was described from south-eastern Australia in 1985. Here we describe additional elements of this species from the same site, and remains of two further extinct species from the Thylacoleo Caves of the Nullarbor Plain, south-central Australia. The skeletal morphology and large size of the three extinct species indicates that they had reduced capacity for flight and were probably primarily ground-dwelling. The extinct species include the two largest-known cuckoos, weighing upwards of 1 kg each. They demonstrate that gigantism in this lineage has been more marked in a continental context than on islands, contrary to the impression gained from extant species. The evolutionary relationships of the Australian fossil coucals are uncertain, but our phylogenetic analysis indicates a possible close relationship between one of the Nullarbor species and extant Centropus violaceus from the Bismarck Archipelago. The presence of three coucals in southern Australia markedly extends the geographical range of the genus from tropical Australia into southern temperate regions. This demonstrates the remarkable and consistent ability of coucals to colonize continents despite their very limited flying ability.

Modelling the current and potential future distributions of the sunn pest Eurygaster integriceps (Hemiptera: Scutelleridae) using CLIMEX

The sunn pest, Eurygaster integriceps (Hemiptera: Scutelleridae), is an economically significant pest throughout Western Asia and Eastern Europe. This study was conducted to examine the possible risk posed by the influence of climate change on its spread. CLIMEX software was used to model its current global distribution. Future invasion potential was investigated using two global climate models (GCMs), CSIRO-Mk3.0 (CS) and MIROC-H (MR), under A1B and A2 emission scenarios for 2030, 2070 and 2100. Dry to temperate climatic areas favour sunn pests. The potential global range for E. integriceps is expected to extend further polewards between latitudes 60° N and 70° N. Northern Europe and Canada will be at risk of sunn pest invasion as cold stress boundaries recede under the emission scenarios of these models. However, current highly suitable areas, such as South Africa and central Australia, will contract where precipitation is projected to decrease substantially with increased heat stress. Estimating the sunn pest's potential geographic distribution and detecting its climatic limits can provide useful information for management strategies and allow biosecurity authorities to plan ahead and reduce the expected harmful economic consequences by identifying the new areas for pest invasion. © 2016 Society of Chemical Industry.

Resource use and greenhouse gas emissions from three wool production regions in Australia

Australia is the largest supplier of fine apparel wool in the world, produced from diverse sheep production systems. To date, broad scale analyses of the environmental credentials of Australian wool have not used detailed farm-scale data, resulting in a knowledge gap regarding the performance of this product. This study is the first multiple impact life cycle assessment (LCA) investigation of three wool types, produced in three geographically defined regions of Australia: the high rainfall zone located in New South Wales (NSW HRZ) producing super-fine Merino wool, the Western Australian wheat-sheep zone (WA WSZ) producing fine Merino wool, and the southern pastoral zone (SA SPZ) of central South Australia, producing medium Merino wool. Inventory data were collected from both case study farms and regional datasets. Life cycle inventory and impact assessment methods were applied to determine resource use (energy and water use, and land occupation) and GHG emissions, including emissions and removal associated with land use (LU) and direct land use change (dLUC). Land occupation was divided into use of arable and non-arable land resources. A comparison of biophysical allocation and system expansion methods for handling co-production of greasy wool and live weight (for meat) was included.Based on the regional analysis results, GHG emissions (excluding LU and dLUC) were 20.1 ± 3.1 (WA WSZ, mean ± 2 S.D) to 21.3 ± 3.4 kg CO2-e/kg wool in the NSW HRZ, with no significant difference between regions or wool type. Accounting for LU and dLUC emissions and removals resulted in either very modest increases in emissions (0.3%) or reduced net emissions by 0–11% depending on pasture management and revegetation activities, though a higher degree of uncertainty was observed in these results. Fossil fuel energy demand ranged from 12.5 ± 4.1 in the SA SPZ to 22.5 ± 6.2 MJ/kg wool (WA WSZ) in response to differences in grazing intensity. Fresh water consumption ranged from 204.3 ± 59.1 in the NSW HRZ to 393.7 ± 123.8 L/kg wool in the WA WSZ, with differences primarily relating to climate. Stress-weighted water use ranged from 11.0 ± 3.0 (SA SPZ) to 74.6 ± 119.5 L H2O-e/kg wool (NSW HRZ) and followed an opposite trend to water consumption in response to the different levels of water stress across the regions. Non-arable grazing land was found to range from 55% to almost 100% of total land occupation. Different methods for handling co-production of greasy wool and live weight changed estimated total GHG emissions by a factor of three, highlighting the sensitivity to this methodological choice and the significance of meat production in the wool supply chain. The results presented improve the understanding of environmental impacts and resource use in these wool production regions as a basis for more detailed full supply chain analysis.

An unprecedented irruption and breeding of Flock Bronzewings Phaps histrionica in central South Australia

The Flock Bronzewing Phaps histrionica has declined significantly and undergone a northward range contraction in inland Australia since European settlement. In the southern parts of its range, including central northern South Australia, it is uncommonly recorded during times of significant ephemeral vegetation response, triggered by sustained above-average rainfall. In late 2013, while core habitats in Queensland were in extended drought and much of arid South Australia received below-average rainfall, an area of ~10 000 km2 between Roxby Downs and Lake Eyre South supported tens of thousands of Flock Bronzewings, with evidence of widespread successful breeding during September and October and contemporary range expansions of 150 km to the south and west. Through a network of local pastoralists, mining workers and biologists we collated ˃80 field observations from >40 observers across this region. Direct evidence of predation by Cats Felis catus was detected at a nest-site and in the stomach of a cat shot in the area. Seeds of annual shrubs Trichodesma and Phyllanthus species dominated the crop contents of two dead fledgling Bronzewings that were collected opportunistically. Although the Flock Bronzewing is well known for its irruptive nature, the magnitude and southerly extent of this sustained irruption are unprecedented in the literature and in the living memory of local observers. This event exemplifies the remarkable ability of arid-adapted birds to locate and exploit localised productive habitat within vast dynamic and stochastic landscapes, in this case recruiting new individuals to the population despite widespread unfavourable conditions within their core range.

Rangeland Condition Monitoring: A New Approach Using Cross-Fence Comparisons of Remotely Sensed Vegetation.

A need exists in arid rangelands for effective monitoring of the impacts of grazing management on vegetation cover. Monitoring methods which utilize remotely-sensed imagery may have comprehensive spatial and temporal sampling, but do not necessarily control for spatial variation of natural variables, such as landsystem, vegetation type, soil type and rainfall. We use the inverse of the red band from Landsat TM satellite imagery to determine levels of vegetation cover in a 22,672km2 area of arid rangeland in central South Australia. We interpret this wealth of data using a cross-fence comparison methodology, allowing us to rank paddocks (fields) in the study region according to effectiveness of grazing management. The cross-fence comparison methodology generates and solves simultaneous equations of the relationship between each paddock and all other paddocks, derived from pairs of cross-fence sample points. We compare this ranking from two image dates separated by six years, during which management changes are known to have taken place. Changes in paddock rank resulting from the cross-fence comparison method show strong correspondence to those predicted by grazing management in this region, with a significant difference between the two common management types; a change from full stocking rate to light 20% stocking regime (Major Stocking Reduction) and maintenance of full 100% stocking regime (Full Stocking Maintained) (P = 0.00000132). While no paddocks had a known increase in stocking rate during the study period, many had a reduction or complete removal in stock numbers, and many also experienced removals of pest species, such as rabbits, and other ecosystem restoration activities. These paddocks generally showed an improvement in rank compared to paddocks where the stocking regime remained relatively unchanged. For the first time, this method allows us to rank non-adjacent paddocks in a rangeland region relative to each other, while controlling for natural spatio-temporal variables such as rainfall, soil type, and vegetation community distributions, due to the nature of the cross-fence experimental design, and the spatially comprehensive data available in satellite imagery. This method provides a potential tool to aid land managers in decision making processes, particularly with regard to stocking rates.

Localization of intraplate deformation through fluid-assisted faulting in the lower-crust: The Flinders Ranges, South Australia

In this paper we present a hypothesis for localized, intraplate deformation in the continental crust of south-central Australia that involves fluid-assisted reactivation of faults in the mid- to lower crust. Using data from a temporary seismometer deployment in the Flinders Ranges, we show that earthquakes, relocated in a 3D velocity model, cluster in elongated low vp/vs anomalies that extend to depths exceeding 20km, and are aligned with the axis of the Flinders Ranges. In the northern Flinders Ranges these low vp/vs anomalies can be interpreted as fractured Neoproterozoic to Cambrian sediments that separate two cratonic blocks, the Gawler Craton to the west and the Curnamona Province in the east. Previous studies of Helium isotopes in springs to the north of the area provide evidence of mantle-derived fluids that may influence faulting at depth. Our focal mechanism and stress inversion results show a regionally compressive stress field that provides no evidence for stress concentration. We also argue that mechanisms for localized faulting such as thermal weakening and isostatic rebound also fail to account for the occurrence of earthquakes at mid- to lower crustal depth in this area of high heat flow and that the focused seismicity can only be explained by high pore fluid pressure in the lower crust.

Influences of the Antarctic Ozone Hole on Southern Hemispheric Summer Climate Change

Abstract Over the past three decades, Antarctic surface climate has undergone pronounced changes. Many of these changes have been linked to stratospheric ozone depletion. Here linkages between Antarctic ozone loss, the accompanying circulation changes, and summertime Southern Hemisphere (SH) midlatitude surface temperatures are explored. Long-term surface climate changes associated with ozone-driven changes in the southern annular mode (SAM) at SH midlatitudes in summer are not annular in appearance owing to differences in regional circulation and precipitation impacts. Both station and reanalysis data indicate a trend toward cooler summer temperatures over southeast and south-central Australia and inland areas of the southern tip of Africa. It is also found that since the onset of the ozone hole, there have been significant shifts in the distributions of both the seasonal mean and daily maximum summertime temperatures in the SH midlatitude regions between high and low ozone years. Unusually hot summer extremes are associated with anomalously high ozone in the previous November, including the recent very hot austral summer of 2012/13. If the relationship found in the past three decades continues to hold, the level of late springtime ozone over Antarctica has the potential to be part of a useful predictor set for the following summer’s conditions. The results herein suggest that skillful predictions may be feasible for both the mean seasonal temperature and the frequency of extreme hot events in some SH midlatitude regions of Australia, Africa, and South America.

Pitjantjatjara

Pitjantjatjara is a dialect of the Western Desert Language (WDL) of central Australia (Douglas 1958). The Western Desert Language is a member of the south-west Pama-Nyungan group. Together with Warnman, it forms the Wati sub-group. It is spoken by 4000–5000 people, and covers the widest geographical area of any language in Australia, stretching from Woomera in central northern South Australia, as far west as Kalgoorlie and Meekatharra and north to Balgo Hills, in Western Australia. The main dialects, which differ most in regards the lexicon but also to some extent in grammar and phonology, include Pitjantjatjara, Yankunytjatjara, Ngaanyatjarra, Ngaatjatjarra, Southern Luritja, Pintupi-Luritja, Kukatja, Gugarda, Ngalia, Wangkatja, Wangkatha, Manyjilyjarra, Kartutjarra and Yurlparija. It is perhaps more accurately conceived of as a dialect chain, whereby a dialect such as Pitjantjatjara is mutually intelligible with its neighbours Ngaanyatjatjarra and Yankunytjatjara, but not with dialects more distant than these, such as Kukatja and Manyjilyjarra.

Remote quantification of phycocyanin in potable water sources through an adaptive model

Cyanobacterial blooms in water supply sources in both central Indiana USA (CIN) and South Australia (SA) are a cause of great concerns for toxin production and water quality deterioration. Remote sensing provides an effective approach for quick assessment of cyanobacteria through quantification of phycocyanin (PC) concentration. In total, 363 samples spanning a large variation of optically active constituents (OACs) in CIN and SA waters were collected during 24 field surveys. Concurrently, remote sensing reflectance spectra (Rrs) were measured. A partial least squares–artificial neural network (PLS–ANN) model, artificial neural network (ANN) and three-band model (TBM) were developed or tuned by relating the Rrs with PC concentration. Our results indicate that the PLS–ANN model outperformed the ANN and TBM with both the original spectra and simulated ESA/Sentinel-3/Ocean and Land Color Instrument (OLCI) and EO-1/Hyperion spectra. The PLS–ANN model resulted in a high coefficient of determination (R2) for CIN dataset (R2=0.92, R: 0.3–220.7μg/L) and SA (R2=0.98, R: 0.2–13.2μg/L). In comparison, the TBM model yielded an R2=0.77 and 0.94 for the CIN and SA datasets, respectively; while the ANN obtained an intermediate modeling accuracy (CIN: R2=0.86; SA: R2=0.95). Applying the simulated OLCI and Hyperion aggregated datasets, the PLS–ANN model still achieved good performance (OLCI: R2=0.84; Hyperion: R2=0.90); the TBM also presented acceptable performance for PC estimations (OLCI: R2=0.65, Hyperion: R2=0.70). Based on the results, the PLS–ANN is an effective modeling approach for the quantification of PC in productive water supplies based on its effectiveness in solving the non-linearity of PC with other OACs. Furthermore, our investigation indicates that the ratio of inorganic suspended matter (ISM) to PC concentration has close relationship to modeling relative errors (CIN: R2=0.81; SA: R2=0.92), indicating that ISM concentration exert significant impact on PC estimation accuracy.

Multi-locus phylogeny of lethal amanitas: implications for species diversity and historical biogeography.

BackgroundLethal amanitas (Amanita section Phalloideae) are a group of wild, fatal mushrooms causing many poisoning cases worldwide. However, the diversity and evolutionary history of these lethal mushrooms remain poorly known due to the limited sampling and insufficient gene fragments employed for phylogenetic analyses. In this study, five gene loci (nrLSU, ITS, rpb2, ef1-α and β-tubulin) with a widely geographic sampling from East and South Asia, Europe, North and Central America, South Africa and Australia were analysed with maximum-likelihood, maximum-parsimony and Bayesian inference methods. Biochemical analyses were also conducted with intention to detect amatoxins and phalloidin in 14 representative samples.ResultLethal amanitas were robustly supported to be a monophyletic group after excluding five species that were provisionally defined as lethal amanitas based on morphological studies. In lethal amanitas, 28 phylogenetic species were recognised by integrating molecular phylogenetic analyses with morphological studies, and 14 of them represented putatively new species. The biochemical analyses indicated a single origin of cyclic peptide toxins (amatoxins and phalloidin) within Amanita and suggested that this kind of toxins seemed to be a synapomorphy of lethal amanitas. Molecular dating through BEAST and biogeographic analyses with LAGRANGE and RASP indicated that lethal amanitas most likely originated in the Palaeotropics with the present crown group dated around 64.92 Mya in the early Paleocene, and the East Asia–eastern North America or Eurasia–North America–Central America disjunct distribution patterns were primarily established during the middle Oligocene to Miocene.ConclusionThe cryptic diversity found in this study indicates that the species diversity of lethal amanitas is strongly underestimated under the current taxonomy. The intercontinental sister species or sister groups relationships among East Asia and eastern North America or Eurasia–North America–Central America within lethal amanitas are best explained by the diversification model of Palaeotropical origin, dispersal via the Bering Land Bridge, followed by regional vicariance speciation resulting from climate change during the middle Oligocene to the present. These findings indicate the importance of both dispersal and vicariance in shaping the intercontinental distributions of these ectomycorrhizal fungi.

Seismic mapping and geomechanical analyses of faults within deep hot granites, a workflow for enhanced geothermal system projects

Areas with deep seated radioactive granites are considered targets for enhanced geothermal system (EGS) projects. These areas normally exhibit high heat flow and temperature anomalies related to granitic bodies. High concentrations of uranium within the granites are the most likely cause of the anomalous temperatures. Elevated temperatures are also resulted to high heat flow and thick sedimentary rock cover that includes insulating materials such as coals and gas reservoirs.In this study we investigated the use of 3D seismic amplitudes and attributes to map deep granitic bodies and faults in the Cooper Basin of South Central Australia. We established a workflow for possible geomechanical fluid flow susceptibility analyses for faults that intersect granites. The far field stress tensor must be interpreted through analyses of image logs and formation tests. Our geomechanical analyses models show how this stress tensor affects basement faults interpreted from 3D seismic surveys. Normal stresses, shear stresses, slip tendency, and distance to failure should be modelled for the faults that cut the granites. The optimal orientation of faults that can be possible conduits are then located. We suggest that the optimal injection and production wells should be located at tips of shallow faults that penetrate the granites. We anticipate that short horizontal faults that are located far from other faults will form a more secure fluid conduit. Finally, this study can be a workflow to evaluate the relative merit of future enhanced geothermal system projects.

Multiple management units of short-beaked common dolphins subject to fisheries bycatch off southern and southeastern Australia

Worldwide, fisheries bycatch remains one of the greatest immediate threats to cetacean populations. In Australia, short-beaked common dolphins are subject to bycatch mortal- ity in 2 fisheries: the purse-seine fishery for sardines off central South Australia and the gillnet fishery for gummy sharks off southern Australia. The cumulative impact of bycatch from both fish- eries on the dolphin population(s) in these regions are unknown. We used information from microsatellite markers and mitochondrial DNA to investigate population genetic structure and estimate contemporary migration rates in 332 biopsied and 15 stranded samples of common dol- phins. Samples were collected from 11 locations along ~3500 km of coastline in southern and southeastern Australia. Bayesian and traditional analyses of population genetic structure revealed the presence of at least 6 management units of common dolphins, of which a minimum of 3 are potentially impacted by the 2 fisheries. These management units need to be managed separately for conservation purposes and for monitoring and mitigation of common dolphin fishery inter - actions off southern and southeastern Australia. We suggest that substructuring and migra - tory movements of common dolphins across these regions may be driven by spatial variations in oceanography, upwelling events and/or fish distribution. This study exemplifies how infor - mation on genetic substructuring in a neritic top predator can be valuable for fisheries bycatch management.

Improved technique for capturing the greater bilby (Macrotis lagotis) using burrow cage traps

The greater bilby (Macrotis lagotis) is generally trap shy and uninterested in baits, therefore difficult to capture. In order to capture an entire population of bilbies in the Arid Recovery Reserve of central South Australia, we developed an improved method of using burrow cage traps. Traps were set to engulf the entrance of the burrow and the base was camouflaged with sand. We obtained a very high capture rate (6% overall, and 73% for confirmed burrows). Assuming that occupied burrows can be detected, this method should improve capture rates for this endangered and cryptic species.

Review on pharmacological and toxicologyical effects of oleum azadirachti oil

Oleum azadirachti consists of the oil obtained from dried seeds of Azadirachta indica A. Juss. (family: Meliaceae). Local names of Azadirachta indica A. Juss. are Abodua, aforo-oyinbo, anwe egyane, arista, azad dirakht, azadarakht, azedarach and bead tree. Indigenous to India, and widely distributed in South and South-East Asia and cultivated in Africa, the South Pacific Islands, South and Central America and Australia, and in southern Florida and California, United States of America, it is a straight-boled deciduous tree, which is 6-25 m high. Bark is dark-brown, externally fissured with a buff inner surface and fibrous fracture. Leaves alternately arranged, pinnately compound and up to 40 cm long, and composed of 8-18 short-petiolate narrow-ovate, pointed and curved toothed leaflets, 3-10 cm long and 1-4 cm wide arranged in alternate pairs. The major constituents are oxidized tetranortriterpenes including azadirachtin (azadirachtin A), azadiriadione, epoxyazadiradione, azadirone, nimbidin, nimbin, deacetylnimbin, salannin, gedunin, mahmoodin, 17-hydroxydiradione and related derivatives. It is of various medicinal uses, such as a contraceptive for intravaginal use, a mosquito repellent, and treatment of vaginal infections, treatment of gastric ulcers, cardiovascular disease, malaria, rheumatism and skin disorders, external applications for treatment of septic wounds, ulcers and boils, treatment of allergic skin reactions, asthma, bruises, colic, conjunctivitis, dysmenorrhoea, fever, gout, headache, itching due to varicella, kidney stones, leukorrhoea, psoriasis, scabies, sprains and muscular pain, and wounds. It is also used as an emmenagogue, tonic, stomatic and vermicide. In conclusion, the plant oil had antifertility, antihyperglycaemic, anti-inflammatory, antimicrobial, antiviral, antiulcer, estrogenic, immune, contraceptive, antibacterial, insect repellent, and skin treatment effects.

The source of A-type magmas in two contrasting settings: U–Pb, Lu–Hf and Re–Os isotopic constraints

The sources of post-orogenic A-type magmas from two distinct geodynamic settings are compared. The end of the ca. 514–480Ma Delamerian Orogeny, southeastern South Australia, was marked by ~10Myr of bimodal A-type magmatism, driven by convective removal of thickened lithosphere. Initial Os and Hf isotope ratios record a heterogeneous lithospheric mantle source, with some input from aesthenospheric mantle. Mafic parental melts fractionated to produce the granites. In contrast, initial Os isotope ratios of the A-type magmas that comprise the ca. 1598–1583Ma Mesoproterozoic Gawler Felsic Large Igneous Province, central South Australia, record a dominant evolved lower crust component. However, initial Hf isotope ratios from these samples are depleted, indicating a mantle source for lithophile elements. This voluminous, bimodal magmatism lasted for ~15Myr, and ended the Wartakan Orogeny. In both cases the homogenisation of chemical (rheological) heterogeneities, inherited from terrain amalgamation and orogenic thickening, strengthened the lithosphere. The contemporaneous fusion of heterogeneous mantle±crust may represent a common, stabilising influence on the lithospheric column regardless of tectono-magmatic setting.

Remote estimation of phycocyanin (PC) for inland waters coupled with YSI PC fluorescence probe

Nuisance cyanobacterial blooms degrade water resources through accelerated eutrophication, odor generation, and production of toxins that cause adverse effects on human health. Quick and effective methods for detecting cyanobacterial abundance in drinking water supplies are urgently needed to compliment conventional laboratory methods, which are costly and time consuming. Hyperspectral remote sensing can be an effective approach for rapid assessment of cyanobacterial blooms. Samples (n=250) were collected from five drinking water sources in central Indiana (CIN), USA, and South Australia (SA), which experience nuisance cyanobacterial blooms. In situ hyperspectral data were used to develop models by relating spectral signal with handheld fluorescence probe (YSI 6600 XLM-SV) measured phycocyanin (PC in cell/ml), a proxy pigment unique for indicating the presence of cyanobacteria. Three-band model (TBM), which is effective for chlorophyll-a estimates, was tuned to quantify cyanobacteria coupled with the PC probe measured cyanobacteria. As a comparison, two band model proposed by Simis et al. (Limnol Oceanogr, 50(11): 237-245, 2005; denoted as SM05) was paralleled to evaluate TBM model performance. Our observation revealed a high correlation between measured and estimated PC for SA dataset (R (2) =0.96; range: 534-20,200 cell/ml) and CIN dataset (R (2) =0.88; range: 1,300-44,500 cell/ml). The potential of this modeling approach for imagery data were assessed by simulated ESA/Centinel3/OLCI spectra, which also resulted in satisfactory performance with the TBM for both SA dataset (RMSE % =26.12) and CIN dataset (RMSE % =34.49). Close relationship between probe-measured PC and laboratory measured cyanobacteria biovolume was observed (R (2) =0.93, p<0.0001) for the CIN dataset, indicating a stable performance for PC probe. Based on our observation, field spectroscopic measurement coupled with PC probe measurements can provide quantitative cyanobacterial bloom information from both relatively static and flowing inland waters. Hence, it has promising implications for water resource managers to obtain information for early warning detection of cyanobacterial blooms through the close association between probe measured PC values and cyanobacterial biovolume via remote sensing modeling.

New constraints on Phanerozoic magmatic and hydrothermal events in the Mt Painter Province, South Australia

Zircon and monazite U–Pb dating show a punctuated history of tectonic, magmatic and hydrothermal activity in the Mt Painter Province (South Australia) that spans most of the Palaeozoic. The Cambro-Ordovician Delamerian Orogeny was characterised by very limited intrusions of sodic pegmatitic leucogranites, for which the Hf isotopic data show influence of an isotopically more primitive source than the local Mesoproterozoic granitoids and metasediments. Another phase of magmatic activity occurred in an intraplate setting around 460–440Ma, with more extensive met- and peraluminous granitoids and another phase of sodic leucogranites. Both intracrustal reworking and potential mantle input are seen at this stage. Iron-rich uranium ores yielded a monazite U–Pb age of 355±5Ma, and whole rock Sm–Nd isotope systematics indicate that the ores were sourced from the local Mesoproterozoic granitoids. The Palaeozoic events in the Mt Painter Province span a period of 200My, and occurred during more than 10km of exhumation of the Mesoproterozoic basement rocks. This study shows that central South Australia was more strongly affected by large-scale regional tectonics (Alice Springs Orogeny and Lachlan Orogeny) than hitherto known.