Browsing by Author "Levchenko, VA"
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- Item12,000-Year-old Aboriginal rock art from the Kimberley region, Western Australia(American Association for Advancement of Science, 2020-02-05) Finch, D; Gleadow, AJM; Hergt, J; Levchenko, VA; Heaney, P; Veth, P; Harper, S; Ouzman, S; Myers, C; Green, HThe Kimberley region in Western Australia hosts one of the world’s most substantial bodies of indigenous rock art thought to extend in a series of stylistic or iconographic phases from the present day back into the Pleistocene. As with other rock art worldwide, the older styles have proven notoriously difficult to date quantitatively, requiring new scientific approaches. Here, we present the radiocarbon ages of 24 mud wasp nests that were either over or under pigment from 21 anthropomorphic motifs of the Gwion style (previously referred to as “Bradshaws”) from the middle of the relative stylistic sequence. We demonstrate that while one date suggests a minimum age of c. 17 ka for one motif, most of the dates support a hypothesis that these Gwion paintings were produced in a relatively narrow period around 12,000 years ago. © 2020 American Association for the Advancement of Science.
- Item129 Holocene records of environment and freshwater availability from tufa archives: implications for human occupation at Murujuga, NW WA(Australasian Quaternary Association, 2022-12-06) Mather, C; Tucker, M; Leopold, M; Levchenko, VA; O'Leary, M; Morrison, P; McDonald, JMurujuga in NW Western Australia is the world’s largest rock art province, with over 1 million engravings. The art and other archaeological evidence in this landscape are an important record of human response to the changing climate following the last ice-age. 130 m of sea level rise following Last Glacial Maximum (LGM ~22 kya) transformed Murujuga from an inland range to a coastal archipelago. We discuss the potential of freshwater tufa as multi-proxy archives to inform on the local environmental and climatic change that impacted this region during the Holocene. Tufa, which are calcium carbonate deposits that form from freshwater springs and seeps in river channels, provide a proxy of past freshwater availability. Establishing the age and rate of tufa formation will enhance our understanding of the presence and permanence of water holes that would have been important for human occupation. Outcomes of this work will provide context to the extraordinary archaeological record documented in Murujuga rock art.
- Item15th International Conference on Accelerator Mass Spectrometry(Australian Nuclear Science and Technology Organisation, 2021-11-15) Bertuch, F; Child, DP; Fink, D; Fülöp, RH; Hotchkis, MAC; Hua, Q; Jacobsen, GE; Jenkinson, A; Levchenko, VA; Simon, KJ; Smith, AM; Wilcken, KM; Williams, AA; Williams, ML; Yang, B; Fallon, SJ; Wallner, TOn behalf of the AMS-15 Organising committee, we would like to thank you for attending the 15th International Conference on Accelerator Mass Spectrometry. Held as an online event for the first time, the 2021 conference attracted over 300 attendees with presentations delivered by colleagues and professionals from around the globe.Applications of AMS to the world’s most pressing problems/questions: A-1 : Earth’s dynamic climate palaeoclimate studies, human impacts on climate, data for climate modelling. A-2 : Water resource sustainability groundwater dating, hydrology, water quality and management A-3 : Living landscapes soil production, carbon storage, erosion, sediment transport, geomorphology. A-4 : Catastrophic natural events volcanoes, cyclones, earthquakes, tsunamis, space weather, mass extinctions. A-5 : Advancing human health metabolic and bio-kinetic studies, bomb-pulse dating, diagnostics and bio-tracing. A-6 : Challenges of the nuclear age nuclear safeguards, nuclear forensics, nuclear waste management, nuclear site monitoring, impacts of nuclear accidents. A-7 :Understanding the human story archaeology, human evolution and migration, history, art and cultural heritage A-8 : Understanding the cosmos fundamental physics, nuclear astrophysics, nuclear physics AMS Research and Development: T-1 : Novel AMS systems, components and techniques T-2 : Suppression of isobars and other interferences T-3 : Ion sourcery T-4 : New AMS isotopes T-5 : Advances in sample preparation T-6 : Data quality and management T-7 : Facility Reports (Poster Presentation only)
- Item7Be and 10Be concentrations in recent firn and ice at Law Dome, Antarctica(Elsevier, 2000-10-01) Smith, AM; Fink, D; Child, DP; Levchenko, VA; Morgan, VI; Curran, MAJ; Etheridge, DM; Elliott, GOver the past three years, the Australian National Tandem for Applied Research (ANTARES) AMS facility at ANSTO has been expanding its sample preparation and measurement capability, particularly for 10Be, 26Al and 36Cl. During this time, ANSTO has continued its collaboration with the AAD and CSIRO Atmospheric Research on the measurement of cosmogenic isotopes from Law Dome, Antarctica. This research program has been supported by the construction of a dedicated geochemistry laboratory for the processing of ice and rock samples for the preparation of AMS targets. Here we present our first results for 10Be concentrations measured in ice cores from three sites at Law Dome and describe the sample processing protocol and aspects of the AMS measurement procedure. These sites are characterised by an eightfold difference in accumulation rate with a common precipitation source. In combination with an established ice chronology, this has enabled some preliminary findings concerning the relationship between the snow accumulation rate and the measured 10Be concentration for Law Dome during recent times. Additionally, we present 7Be and 10Be/7Be measurements made for a few surface snow samples from Law Dome and Australia. © 2000 Elsevier Science B.V.
- ItemThe ANSTO – University of Wollongong in-situ 14C extraction laboratory(Elsevier, 2019-01-01) Fülöp, RH; Fink, D; Yang, B; Codilean, AY; Smith, AM; Wacker, L; Levchenko, VA; Dunai, TJWe present our first 14C in-situ results for calibration and system blanks from the recently completed Australian Nuclear Science and Technology Organisation (ANSTO) – University of Wollongong (UOW) in-situ 14C extraction system. System performance parameters and quality is evidenced by low 14C blanks and good reproducibility for multiple targets from different reference materials. The 14C extraction scheme exploits the high temperature phase transformation of quartz to cristobalite in order to quantitatively extract the carbon as CO2. The in-situ 14C extraction system comprises three independently operated and modular units that are used for initial in-vacuo removal of meteoric 14C, followed by offline high-temperature heating of quartz to release trapped cosmogenic in-situ 14C, and finally CO2 gas purification and mass measurement. The design allows for rapid sample throughput of about 6 samples per week with samples masses ranging between 0.5 and 4 g of clean quartz. Other features include single-pass catalytic oxidation using mixed copper (I,II) oxide as catalyst, use of UHV-compatible components and of vacuum annealed copper tubing. We present results for sets of purified quartz samples prepared from CRONUS-A, CRONUS-R and CRONUS-N inter-comparison materials, with final averages consistent with published values. Following extraction and cleaning, CO2 gas aliquots for some of the samples were analysed using the ETH Zürich CO2 gas ion source at the ETH MICADAS AMS facility in addition to CO2 being graphitised using the ANSTO laser-heated graphitisation micro-furnace and then analysed on ANSTO’s ANTARES AMS facility. System blanks using either CO2 or graphite ion-sources at both facilities are on the order of ∼1 × 104 atoms. © 2018 Elsevier B.V.
- ItemThe ANTARES AMS Centre : a status report(Cambridge University Press, 2016-07-18) Tuniz, C; Fink, D; Hotchkis, MAC; Jacobsen, GE; Lawson, EM; Smith, AM; Hua, Q; Drewer, P; Lee, P; Levchenko, VA; Bird, R; Boldeman, JW; Barbetti, M; Taylor, G; Head, JThe ANTARES accelerator mass spectrometry facility at Lucas Heights Research Laboratory is operational and AMS measurements of 14C, 26Al and 36Cl are being carried out routinely. Measurement of 129I recently commenced and capabilities for other long-lived radioisotopes such as 10Be are being established. The overall aim of the facility is to develop advanced programs in Quaternary science, global climate change, biomedicine and nuclear safeguards. © the Department of Geosciences, The University of Arizona
- ItemAtmospheric 14C variations derived from tree rings during the early Younger Dryas(Elsevier, 2009-12) Hua, Q; Barbetti, M; Fink, D; Kaiser, KF; Friedrich, M; Kromer, B; Levchenko, VA; Zoppi, U; Smith, AM; Bertuch, FAtmospheric radiocarbon variations over the Younger Dryas interval, from ~13,000 to 11,600 cal yr BP, are of immense scientific interest because they reveal crucial information about the linkages between climate, ocean circulation and the carbon cycle. However, no direct and reliable atmospheric 14C records based on tree rings for the entire Younger Dryas have been available. In this paper, we present (1) high-precision 14C measurements on the extension of absolute tree-ring chronology from 12,400 to 12,560 cal yr BP and (2) high-precision, high-resolution atmospheric 14C record derived from a 617-yr-long tree-ring chronology of Huon pine from Tasmania, Australia, spanning the early Younger Dryas. The new tree-ring 14C records bridge the current gap in European tree-ring radiocarbon chronologies during the early Younger Dryas, linking the floating Lateglacial Pine record to the absolute tree-ring timescale. A continuous and reliable atmospheric 14C record for the past 14,000 cal yr BP including the Younger Dryas is now available. The new records indicate that the abrupt rise in atmospheric Δ14C associated with the Younger Dryas onset occurs at ~12,760 cal yr BP, ~240 yrs later than that recorded in Cariaco varves, with a smaller magnitude of ~40‰ followed by several centennial Δ14C variations of 20–25‰. Comparing the tree-ring Δ14C to marine-derived Δ14C and modelled Δ14C based on ice-core 10Be fluxes, we conclude that changes in ocean circulation were mainly responsible for the Younger Dryas onset, while a combination of changes in ocean circulation and 14C production rate were responsible for atmospheric Δ14C variations for the remainder of the Younger Dryas. © 2009, Elsevier Ltd.
- ItemBeeswax as dental filling on a Neolithic human tooth(Public Library of Science, 2012-09-19) Bernardini, F; Tuniz, C; Coppa, A; Mancini, L; Dreossi, D; Eichert, D; Turco, G; Biasotto, M; Terrasi, F; De Cesare, N; Hua, Q; Levchenko, VAEvidence of prehistoric dentistry has been limited to a few cases, the most ancient dating back to the Neolithic. Here we report a 6500-year-old human mandible from Slovenia whose left canine crown bears the traces of a filling with beeswax. The use of different analytical techniques, including synchrotron radiation computed micro-tomography (micro-CT), Accelerator Mass Spectrometry (AMS) radiocarbon dating, Infrared (IR) Spectroscopy and Scanning Electron Microscopy (SEM), has shown that the exposed area of dentine resulting from occlusal wear and the upper part of a vertical crack affecting enamel and dentin tissues were filled with beeswax shortly before or after the individual's death. If the filling was done when the person was still alive, the intervention was likely aimed to relieve tooth sensitivity derived from either exposed dentine and/or the pain resulting from chewing on a cracked tooth: this would provide the earliest known direct evidence of therapeutic-palliative dental filling. © 2012, The Authors
- ItemBeryllium-10 in forams and marine sediments; a new chemo-stratigraphic tracer for the late quaternary(Eleventh International Conference on Accelerator Mass Spectrometry, 2008-09) Levchenko, VA; Opdyke, BN; Fink, D; Mifsud, C; Williams, AAThe production rate of cosmogenic isotopes 10Be and 14C is influenced by varitions in the primary cosmic ray flux and by charges of the Earth's magnetic field, which has experienced a number of significant perturbations during the late Quaternary (e.g. Lashamp Mono Lake excursion, circa 41 ka BP). Understanding these changes and synchronising variations in palaeomagnetic intensity derived from various marine sediment cores can often help constrain the quality of 14C dating, particularly in the interval between 20 and 50 ka ago, and establish reliable chronologies for ocean sedimentation rate changes. A common proxy for these palaeomagnetic changes is atmospheric fallout of 10Be in bulk sediments. However terrigenous and recycled sediments also deliver high 10Be concentrations thus strongly complicating the process required to isolate direct atmospheric from continental derived 10Be. As an alternative to geochemical speciation, grain size or leaching procedures in sediments we suggest that changes in 10Be concentrations in planktonic foraminifera can be used as a global stratigraphic marker. We are investigating planktonic foraminifera collected from Core MD - 982167, which was recovered from the Scott Plateau in the Eastern Indian Ocean at latitude of 13° S. The MD- 982167 already has an established stable isotope stratigraphy and a high sedimentation rate of 10 to 20 cm per ka. Initial results of paired 14C and 10Be determinations in foraminifera and fine fraction of the core sediments as a function of core depth have been obtained and subsequently will be compared to palaeomagnetic measurements currently in progress. An improved chronology for this high resolution core that has recorded brief, less than one thousand year duration, climatic events during the studied time interval will allow much better correlation between marine sedimentary records and the detailed chronologies established from the ice cores.
- ItemA bright future for accelerator science at ANSTO(Australian Institute of Nuclear Science and Engineering (AINSE), 2009-11-25) Hotchkis, MAC; Child, DP; Cohen, DD; Dodson, JR; Fink, D; Garton, D; Hua, Q; Ionescu, M; Jacobsen, GE; Levchenko, VA; Mifsud, C; Siegele, R; Smith, AM; Williams, AG; Winkler, SIn the May 2009 budget, the Federal Government announced funding of $25m to ANSTO through the Education Investment Fund, to build state-of-the-art applied accelerator science facilities, by upgrading and replacing existing facilities and laboratories at ANSTO. Currently, ANSTO's researchers, jointly with researchers from all 37 Australian universities, plus other agencies such as CSIRO, government departments and local government bodies, and overseas collaborators and customers, use ANSTO's accelerator facilities for analysis of a wide range of materials, predominantly by Accelerator Mass Spectrometry (AMS) and Ion Beam Analysis (IBA). There are >100 external users of those facilities every year. © 2009 AINSE
- ItemBuilding the radiocarbon chronology for the archaeological site Ufa-II: is this the elusive "bashkort" of medieval sources?(University of Arizona Department of Geosciences, 2013-01-01) Levchenko, VA; Sungatov, FAA suite of accelerator mass spectrometry (AMS) radiocarbon dates for the Ufa-II archaeological site in Bashkortostan, Russia, is obtained for the first time. Dating was done on charcoal samples from a sequence of cultural deposits collected during the 2011 digging season. An age-depth chronology is established using the Bayesian deposition General Outlier P_Sequence model. The oldest age for the site at the horizon immediately over the sterile ground was cal AD 137-237 (68% probability), corresponding to the beginning of site occupation. The youngest C-14 date found was late 6th to early 7th century cal AD for the extensive planked boardwalks unearthed at the site. The C-14 dates are in good agreement with archaeological determinations based on discovered artifacts. © 2013, University of Arizona.
- ItemCave lion skeleton from the Maly Anyuy River (Chukotka, Russia)(School of Geology, Aristotle University of Thessaloniki, 2014-04-01) Kirrillova, IV; Tiunov, AV; Levchenko, VA; Chernova, OF; Bertuch, F; Shidlovsky, FKCave lion (Panthera spelaea) remains, like skeletons, skulls and individual bones, have been discovered all over the mammoth fauna range from Iberian Peninsula to North America. In Russia these finds are scattered and seldom. In summer 2008 a compact cluster of cave lion remains belonging to a single specimen, a tuft of visually unidentified ginger-coloured hair and a horse vertebra were found in the water under the bank outcrop of Maly Anuy River (68.18 N, 161.44 E), Chukotka, Russia. The find included 36 vertebrae, 20 ribs, limbs bones: scapula, humerus, pelvic, femur, tibia, 6bula, patellae, talus, metatarsal, and third phalanx with cover. In 2009 on the same spot the cave lion mandibular bones were found. Their age, sex and features support the probability of belonging to the same specimen as the skeleton prior. Bone sizes (mandible length: 255.7-262.0 mm; P3-M1 mean alveolar length: 80.2 mm; mean LxB of M1: 29.5x14.9 mm; M1 mean height (buccal): 53.5 mm; length of humerus: 386.1 mm, of femur: 431.5 mm, of tibia: 362.0 mm) fell within the range of other cave lion finds. Some bones display deformities and age-related changes, e.g. an asymmetry of thoracic and sacral vertebrae, a notch on the scapula, sclerotized ligaments on the femur and tibia, osteophytes on the ribs. Vertebrae asymmetry is probably a result of young age trauma. Sclerotized ligaments are likely a sign of myositis – common for musculoskeletal overloads. The mandibles bear traces of age-related changes and pathological cortex transformation due to periostitis, usually from traumatic injuries. The noted features are not a sign of systemic illness though. The bone cortex, apart from the mandible outer surface, is dense and healthy; joint surfaces show no traces of degradation; muscle origins and insertions are clearly pronounced on the bones that testifies a high motor activity of the animal. The skeleton evidently belonged to a mature but not old male. The age, from counting the annual layers in canine cementum, was about 12 years. The claw sheath on the third phalanx and fur sample are of particular interest, since the cave lion skin derivatives have not been discovered previously. Stable isotope analyses of samples taken from a few bones, fur and claw sheath of the finds were done to check the possible diet of the animal and specimens identity. The results compared with five more specimens of cave lion and some representatives of mammoth fauna from Chukchi and Yakut territories, namely mammoth, woolly rhinoceros, bison, horse, two species of deer, bighorn sheep and wolf (all samples from the Ice Age Museum, Moscow). The isotopic signature of the Anuy lion remains testifes that all of them nearly certainly came from the same individual, yet the mandible slightly differs from the rest. Stable isotope studies for this cave lion also define that the main prey included Bison, Equus and Ovibos. Notably, reindeer (Rangifer tarandus) was not among its most probable prey. The obtained stable isotope results for the found lion remains and its potential diet deviate from these for Western Europe, where reindeer remained the main food source (Bocherens et al., 2011). This deviation can be explained by relatively smaller reindeer population in the Asian North-East compared to the other available ungulate prey. The tuft of fur found near the cave lion’s remains has good differentiation: guard hair (I–IV categories) (GH) and woolly hair (I–II categories) (WH). GH colour varies from light-yellow to dark-brown, without a black tip. WH is light-yellow or whitish. GH type I are typical primary hairs, which, judging by their fragments of length up to 50 mm, are long, thick (up to 200 μm), strong and smooth. The shape of shaft at the base is cylindrical, but in the middle one side flattens a little. The medulla is well-developed, occupies up to 80% of the shaft diameter and runs through its middle. GH of other categories are thinner (45–90 μm) and have medulla less developed. WH are long, with 3–6 bends looking like elastic springs. In the bends the medulla is shifted in the direction of lesser radii. Unlike the modern lion’s the found fur has very thick and dense woolly undercoat of numerous closely shut and compressed wavy woolly hairs with the medulla. The coloration of the hair is not fully similar to that of the modern lion. The microstructure and degree of development of the medulla and the cortex, and the ornament of the cuticle look similar between modern species and the found sample, but the cuticular scales of the find are larger. Because of the small size of the tuft and absence of other cave lion hair samples for comparison it is not possible to determine its origin topographically or relate to a season. Its attribution to a lion is still debatable. Radiocarbon AMS dating was performed at ANSTO (Fink et al., 2004) for samples taken from a rib, claw sheath and fur tuft (lab codes OZQ290, OZQ291, OZQ292). Bone sample exhibited good collagen preservation, consistent with its origin from permafrost. Keratin was analysed for claw and fur. Both rib and claw gave 14C dates greater than 61 thousand years. Fur in contrast came out much younger (28690+130 14C years), which makes it impossible to come from the same specimen as the bones. However, its stable isotope signature fits that for the carnivore. The remains from the Maly Anuy River represent the first associated skeleton of cave lion found in Russia and the most ancient for the region.
- ItemThe Centre for Accelerator Science at ANSTO(International Atomic Energy Agency, 2014-01-14) Hotchkis, MAC; Child, DP; Cohen, DD; Dodson, JR; Fink, D; Fujioka, T; Garton, D; Hua, Q; Ionescu, M; Jacobsen, GE; Levchenko, VA; Mifsud, C; Pastuovic, Z; Siegele, R; Smith, AM; Wilcken, KM; Williams, AGIn 2009, the Federal government provided funding of $25m to ANSTO through the Education Investment Fund, to build state-of-the-art applied accelerator science facilities, with the primary aim of providing world-leading accelerator mass spectrometry (AMS) and ion beam analysis (IBA) facilities. New buildings are now under construction and Building plans are now well advanced, and two new accelerators are on order with National Electrostatics Corporation, USA. The 1MV AMS accelerator system is designed with the capability to perform high efficiency, high precision AMS analysis across the full mass range. Large beam-optical acceptance will ensure high quality and high throughput radiocarbon measurements. High mass resolution analyzers, at low and high energy, coupled to a novel fast isotope switching system, will enable high quality analysis of actinide radioisotopes. The 6MV tandem accelerator will be instrumented with a wide range of AMS, IBA and ion irradiation facilities. The three ion sources include hydrogen and helium sources, and a MCSNICS sputter source for solid materials. The AMS facility has end stations for (i) a gasabsorber detector for 10Be analysis, (ii) a time-of-flight detector, (iii) a gas-filled magnet and(iv) a general use ionization detector suited to 36Cl and other analyses. Initially, there will be four IBA beamlines, including a new ion beam microprobe currently on order with Oxford Microbeams. The other beamlines will include an on-line ion implanter, nuclear reaction analysis and elastic recoil detection analysis facilities. The beam hall layout allows for future expansion, including the possibility of porting the beam to the existing ANTARES beam hall for simultaneous irradiation experiments.Two buildings are currently under construction, one for the new accelerators and the other for new chemistry laboratories for AMS and mass spectrometry facilities. The AMS chemistry labs are planned in two stages, with the new radiocarbon labs to come in the second phase of work.
- ItemChoosing the right stripper gas from AMS and other applications with tandem accelerators at low and medium terminal voltage(Department of Nuclear Physics Research School of Physics and Engineering, The Australian National University, 2013-04-11) Hotchkis, MAC; Child, DP; Fink, D; Levchenko, VA; Wilcken, KMRecent experimentation with stripper gases used for Accelerator Mass Spectrometry (AMS) has seen a divergence in the practices adopted at laboratories performing AMS of high mass species (such as actinides) at low and medium terminal voltages. At low voltages (<1 MV), the Ion Beam Group at ETH Zurich has demonstrated the advantages of using helium as the stripper gas, for both radiocarbon AMS  and for actinides AMS . Meanwhile, at ANSTO we have investigated several gases at 4 MV [3, 4] and find that a multi–atom molecular gas such as sulphur hexafluoride provides the best yield for actinides AMS. In both cases, data published 40 years ago provided clues as to the optimum gas in each situation.
- ItemCorrigendum to "Gas transport in firn: multiple-tracer characterisation and model intercomparison for NEEM, Northern Greenland'' published in Atmos. Chem. Phys., 12, 4259–-4277, 2012(Copernicus Publications, 2014-04-09) Buizert, C; Martinerie, P; Petrenko, VV; Severinghaus, JP; Trudinger, CM; Witrant, E; Rosen, JL; Orsi, AJ; Rubino, M; Etheridge, DM; Steele, LP; Hogan, C; Laube, JC; Sturges, WT; Levchenko, VA; Smith, AM; Levin, I; Conway, TJ; Dlugokencky, EJ; Lang, PM; Kawamura, K; Jenk, TM; White, JWC; Sowers, T; Schwander, J; Blunier, TIt was kindly pointed out to us by M. Battle that Eq. (2) on p. 4263 contains a typo, and should instead be [X]corr(z) = [X]meas(z) ΔMδgrav(z)/1000 + 1 , (2) where [X]corr ([X]meas) is the gravity-corrected (measured) mixing ratio of gas species X, 1M = MX − Mair is the molar mass difference between gas X and air, and grav(z) is the gravitational fractionation per unit mass difference at depth z. All calculations in the study were done correctly, following Eq. (2) as given here. Furthermore, the present-day 1age value for NEEM is incorrect in the original manuscript, and underestimates Δage by 6 years. The correct value is 188+3 −9 yr. In our original, incorrect calculation we used the ice age in years before 2000 CE (b2k), while we should have used the ice age relative to the surface ice age. In the updated 1age calculation we use the ice age found by annual layer counting of the shallow NEEM 2011 S1 core (Sigl et al., 2013). The NEEM chronology published in Rasmussen et al. (2013) uses the correct, updated Δage estimate. Both errors addressed in this corrigendum affect neither the discussion nor the main conclusions of the original publication. © Author(s) 2014.
- ItemCosmogenic radionuclides at Law Dome, East Antarctica, as signatures of past Solar storm events.(Australian Nuclear Science and Technology Organisation, 2021-11-17) Smith, AM; Curran, MAJ; Fink, D; Dee, MW; Kuitems, M; Levchenko, VA; Moy, A; Scifo, A; Simon, KJ; Wilcken, KMThis project investigates evidence for increased atmospheric production of cosmogenic radionuclides in ice core records at Law Dome, East Antarctica, during three extreme events. These events are the Carrington Event (CE) of 1859 AD , the largest solar storm of modern times, and two recently discovered cosmic radiation events of even greater magnitude, the Miyake Events (ME) of 774/5 AD  and 993/4 AD . Our intention is to determine ¹⁴ C, ¹⁰ Be and ³⁶ Cl profiles, with the highest sub-annual temporal resolution to date, across these events to determine whether or not all three events are manifestations of the same phenomena. Understanding the frequency, origin and magnitude of these events is essential for future-proofing modern communication infrastructure against such high magnitude radiation impacts from space. Identification of the events also provides an independent check on the Law Dome ice chronology. New annual Δ¹⁴ C measurements in tree rings, in combination with earlier published data, show that the ME774 and the ME993 events occurred in close proximity to the point of maximum activity of the 11-year solar cycle . Although it did not leave any radiocarbon signature, the CE1859 event was already known to have occurred around the point of maximum activity of the solar cycle from sunspot records. Ice samples for ¹⁰ Be and ³⁶ Cl analysis are derived from ice cores drilled near the summit of Law Dome, East Antarctica. This is the first time these radionuclides have been measured at the same site for these events, allowing a direct comparison of ME774, ME993 and CE1859 under similar transport conditions. Both ME samples were taken from sections of core where the amount of available ice was limited, and the CE samples were taken from a section where more ice was available. AMS measurements involved some method development at ANSTO, measuring both ¹⁰ Be and ³⁶ Cl in the same samples, with sample sizes challenging for the ME samples. Preliminary ¹⁰ Be results at annual resolution spanning 30 years allowed an exact location of the events. We have clearly identified the expected ME774 and ME993 ¹⁰ Be peaks, which were ~ 4 years and ~ 2 years, respectively, within the error of when the layer-counted DSS ice core chronology had suggested. Accordingly, a further set of ¹⁰ Be samples at sub-annual seasonal resolution have been taken to better define the fine structure and amplitude of the signal but are currently not processed. We will also prepare a set of ³⁶ Cl AMS targets from the sub-annual ice core samples and the initial annual survey samples. No discernible ¹⁰ Be peak or ³⁶ Cl peak was found for CE1859 at annual resolution. © The Authors
- ItemCultural heritage project at Australian Nuclear Science and Technology Organisation (ANSTO)(Springer Nature, 2022-01-25) Salvemini, F; White, R; Levchenko, VA; Smith, AM; Pastuovic, Z; Stopic, A; Luzin, V; Tobin, MJ; Puskar, L; Howard, DL; Davis, J; Avdeev, M; Gatenby, S; Kim, MJ; Grazzi, F; Sheedy, K; Olsen, SR; Raymond, CA; Lord, C; Richards, C; Bevitt, JJ; Popelka-Filcoff, RS; Lenehan, CE; Ives, S; Dredge, P; Yip, A; Brookhouse, MT; Austin, AGThe Australian Nuclear Science and Technology Organization (ANSTO) is the home of Australia’s most significant landmark and national infrastructure for research. ANSTO operates one of the world’s most modern nuclear research reactors, OPAL; a comprehensive suite of neutron beam instruments; the Australian Synchrotron; the Electron Microscope Facility; and the Center for Accelerator Science. Over the years, the suite of nuclear methods available across ANSTO’s campuses has been increasingly applied to study a wide range of heritage materials. Since 2015 the strategic research project on cultural heritage was initiated in order to promote access to ANSTO’s capabilities and expertise, unique in the region, by cultural institution and researchers. This chapter offers a compendium of ANSTO nuclear capabilities most frequently applied to cultural heritage research. A series of innovative, interdisciplinary, and multi-technique studies conducted in close collaboration with Australian museums, institutions, and universities is also showcased. It includes research on dating Aboriginal Australian rock art and fingerprinting the sources of ochre pigments; rediscovering the technological knowledge in the making of early coinage and ancient weapons; virtually unwrapping the content of votive mummies from ancient Egypt; and investigating and restoring the original layer of a painting that can be explored by the museum audience in a novel type of exhibition based on an immersive, interactive, and virtual environment. © 2022 Springer Nature Switzerland AG
- ItemCultural innovation and megafauna interaction in the early settlement of arid Australia(Springer, 2016-11-02) Hamm, G; Mitchell, P; Arnold, LJ; Prideaux, GJ; Questiaux, D; Spooner, NA; Levchenko, VA; Foley, EC; Worthy, TH; Stephenson, B; Coulthard, V; Coulthard, C; Wilton, S; Johnston, DElucidating the material culture of early people in arid Australia and the nature of their environmental interactions is essential for understanding the adaptability of populations and the potential causes of megafaunal extinctions 50–40 thousand years ago (ka). Humans colonized the continent by 50 ka1, 2, but an apparent lack of cultural innovations compared to people in Europe and Africa3, 4 has been deemed a barrier to early settlement in the extensive arid zone2, 3. Here we present evidence from Warratyi rock shelter in the southern interior that shows that humans occupied arid Australia by around 49 ka, 10 thousand years (kyr) earlier than previously reported2. The site preserves the only reliably dated, stratified evidence of extinct Australian megafauna5, 6, including the giant marsupial Diprotodon optatum, alongside artefacts more than 46 kyr old. We also report on the earliest-known use of ochre in Australia and Southeast Asia (at or before 49–46 ka), gypsum pigment (40–33 ka), bone tools (40–38 ka), hafted tools (38–35 ka), and backed artefacts (30–24 ka), each up to 10 kyr older than any other known occurrence7, 8. Thus, our evidence shows that people not only settled in the arid interior within a few millennia of entering the continent9, but also developed key technologies much earlier than previously recorded for Australia and Southeast Asia. © 2016, Nature Publishing Group.
- ItemDating correlated microlayers in engraved, oxalate-rich accretions: new archives of paleoenvironments and human activity from Australian rock art shelters(Australian Nuclear Science and Technology Organisation, 2021-11-17) Green, H; Finch, D; Gleadow, AJM; Hoy, J; Levchenko, VA; Myers, C; Heaney, P; Pickering, RDistinctive, dark coloured, glaze-like mineral accretions, often found in rock shelters around the world, offer important opportunities for radiocarbon dating of associated rock art. The mineralogy of these accretions is dominated by well-crystallised calcium oxalate and sulphate minerals, most commonly whewellite and gypsum, with significant occurrences of phosphates in some samples. The accretions are typically several millimetres thick and characterised by distinctive internal laminations that exhibit regular stacked undulations giving a stromatolitic appearance under the microscope. Together with other apparently microbial features observed under the SEM, these features provide strong support for a microbiological origin for these oxalate-rich accretions. Risks surrounding contamination and open system behaviour, previously limiting the application of radiocarbon dating to these accretions, are addressed by the well-crystallised nature of the oxalates and the preservation of fine laminar features within their internal stratigraphies. In a case study from the north Kimberley region of north-western Australia, we demonstrate the use of sample characterisation and chemical pre-treatment techniques to pre-screen for evidence of open system behaviour and address potential contamination. The results provide stratigraphically consistent sequences of radiocarbon dates in mm-scale laminated accretions, with correlations between distinctive patterns in the layer sequences visible in rock shelters up to 90 km apart. This demonstrates that pre-screened samples offer opportunities to reliably date rock art, particularly symbolic markings commonly engraved into these relatively soft deposits and suggests their synchronised formation is not entirely shelter specific but broadly controlled by variations in regional environmental conditions. Consequently, these accretions also offer potential as paleoenvironmental archives, with radiocarbon dating of layers in nine accretions indicating four, approximately synchronous growth intervals covering the last 43 ka.
- ItemDevelopments in micro-sample 14C AMS at the ANTARES AMS facility(Elsevier, 2010-04-01) Hua, Q; Williams, AA; Levchenko, VA; Ying, B; Smith, AMWe continue development of micro-sample radiocarbon sample preparation and AMS measurement at the ANTARES AMS facility. We routinely prepare samples containing 10–200 μg of carbon using an iron catalyst with an excess of hydrogen in 2.5 mL graphitisation reactors. These use a tube furnace to heat the catalyst to 600°C and a Peltier-cooled water trap. Samples containing just a few micrograms of carbon can be prepared. We describe progress with a 0.5 mL laser-heated ‘microfurnace’ we are developing for the rapid and efficient graphitisation of 5 μg samples. Following operating experience with a prototype unit, work has commenced on the development of a second-generation device with the goal of fully automated operation with minimal introduction of extraneous carbon. Key to development of micro-sample 14C AMS is the ability to reliably handle the graphite/iron sample and to mount it in the ion source target holder. We have developed a target holder that permits the sample to be loaded in a 1 mm diameter recess and rear pressed, ensuring a high quality surface finish, at a reproducible depth. Additionally we have developed a method for systematically aligning the sample stage with the cesium beam following ion source servicing. Crown copyright © 2009 Published by Elsevier B.V.