scholarly journals Huts and stone arrangements at Hilary Creek, western Queensland: Recent fieldwork at an Australian Aboriginal site complex

2021 ◽  
Vol 24 ◽  
pp. 1-47
Author(s):  
Lynley Wallis ◽  
Bryce Barker ◽  
Heather Burke ◽  
Mia Dardengo ◽  
Robert Jansen ◽  
...  
Keyword(s):  
Radiocarbon Dating ◽  
Mussel Shell ◽  
Australian Aboriginal ◽  
Small Stone ◽  
Extensive Surface ◽  
Colonial Violence ◽  
Two Phases

This paper reports on an Aboriginal site complex, incorporating hut structures, ceremonial stone arrangements, an extensive surface artefact assemblage of lithics and mussel shell, and a silcrete quarry, located along Hilary Creek, a tributary of the Georgina River in western Queensland, Australia. At least two phases of occupation are indicated. The most recent huts have their collapsed organic superstructure still present, while those of a presumably earlier phase are distinguished as bare, circular patches of earth which are conspicuous amongst the ubiquitous gibber, with or without stone bases, and lacking any collapsed superstructure. Immediately adjacent to the huts and also a few hundred metres away are clusters of small stone arrangements, and about 2 km to the southwest, along the same creekline, is another series of larger, more substantial stone arrangements; these features speak to the importance of the general Hilary Creek area for ceremonial purposes. Radiocarbon dating reveals use of the Hilary Creek complex dates to at least 300 years ago; the absence of any European materials suggests it was likely not used, or only used very sporadically, after the 1870s when pastoralists arrived in the area, and when traditional lifeways were devastated by colonial violence.

scholarly journals CALCIUM OXALATE RADIOCARBON DATING: PRELIMINARY TESTS TO DATE ROCK ART OF THE DECORATED OPEN-AIR CAVES, ERONGO MOUNTAINS, NAMIBIA

Radiocarbon ◽  
2020 ◽  
pp. 1-12
Author(s):  
Jean-Pascal Dumoulin ◽  
Matthieu Lebon ◽  
Ingrid Caffy ◽  
Guilhem Mauran ◽  
Alma Nankela ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Calcium Oxalate ◽  
Organic Compounds ◽  
Radiocarbon Dating ◽  
Rock Art ◽  
Targeted Sampling ◽  
Heritage Site ◽  
Carbon Compounds ◽  
First Results ◽  
Two Phases

ABSTRACT The direct dating of rock paintings is not always possible due to the lack of organic carbon compounds in pigments, or because sampling from a heritage site is often restricted. To overcome these limitations, dating laboratories have to develop new approaches. In this study, we consider sampling calcium oxalate crusts covering the painted artworks as a way to indirectly date the rock art. This stratigraphic approach includes isolating and extracting pure oxalate from the crusts. The approach was tested on natural bulk accretions collected in the open-air sites of Erongo Mountains in Namibia. The accretions were separated into two phases (pure oxalate and the remaining residues) with a special pretreatment. This process removes carbonates through acidification (HCl 6N) and dissolves the oxalate into the supernatant, leaving the minerals and windblown organic compounds in the residue. The efficiency of the separation was checked on the two phases by FTIR analyses and by 14C dating and showed that pure oxalate powders were indeed obtained. AMS radiocarbon results of various accretions on the same art panels provided ages from modern periods to 2410 ± 35 BP. From these first results, more targeted sampling campaigns can be considered to provide a terminus ante quem for the rock art.

scholarly journals Radiocarbon Dating with the Utrecht Tandem Accelerator

Radiocarbon ◽  
1983 ◽  
Vol 25 (2) ◽  
pp. 739-744 ◽  
Author(s):  
K van der Borg ◽  
J A Hoogenboom ◽  
R A Jelmersma ◽  
Abraham Vermeer ◽  
Gert Hut
Keyword(s):  
Mass Spectrometry ◽  
Periodic System ◽  
Radiocarbon Dating ◽  
Isotope Ratios ◽  
High Accuracy ◽  
Important Application ◽  
Second Phase ◽  
Tandem Accelerator ◽  
Two Phases ◽  
Rapid Switching

In 1979 when accelerator mass spectrometry was started in the Netherlands, Gove (1978) and Litherland (1980) demonstrated that a tandem accelerator is eminently suited for this work. Isotope ratios below 10−15 could be determined and applications were stimulated on numerous fields of research. 14C dating in particular would become an important application because smaller samples could be employed and more complex dating problems could be attacked. However, the 5% accuracy reached at that time had to be improved towards the 0.5% obtained with the conventional method of counting decays. Purser and Hanley (1978) pointed out that this high accuracy could be reached in facilities especially dedicated to dating. Rapid switching between measurements on different isotopes turned out to be crucial (Suter et al, 1981). We decided to proceed in two phases. In the first phase, the existing EN-tandem facility would be used as before and modified for the detection of 14C ions. From measurements with 14C ions from different samples, information would be obtained about the limitations of the existing facility. In the second phase, this information would be used to develop a facility in which accurate measurements of isotope ratios can be performed for elements throughout the periodic system. Conventional 14C dating will be extended in collaboration with the Isotope Physics Laboratory in Groningen. Also, applications with other elements will be studied. The improved facility is scheduled for operation in the spring of 1983.

Radiocarbon ages and the full-glacial to Holocene transition in seas adjacent to Scotland and southern Scandinavia: a review

1990 ◽  
Vol 81 (4) ◽  
pp. 385-396 ◽  
Author(s):  
J. D. Peacock ◽  
D. D. Harkness
Keyword(s):  
North Atlantic ◽  
Radiocarbon Dating ◽  
East Coast ◽  
Younger Dryas ◽  
Southern Sweden ◽  
Marine Strata ◽  
Southern Scandinavia ◽  
Two Phases ◽  
Nw Europe ◽  
Polar Water

ABSTRACTWater of southerly origin replaced polar water very rapidly on the coast of NW Europe and an interstadial marine circulation with a weak North Atlantic Drift was fully established off both west Scotland and southern Scandinavia by roughly 12 800BP. A ‘warm’ interval detected in marine strata on the western Scottish coast at the beginning of the Windermere (Bølling plus Allerød) Interstadial lasted from this date to perhaps 12 400 BP and another towards its close from about 11 250 to shortly after 11 000 BP. During the Younger Dryas Stadial polar water returned by about 10 850 BP and was present until about 10 200–10 100 BP. The changes in water circulation at the beginning and end of the Windermere Interstadial and at the end of the Younger Dryas seem to have taken place within the limits of radiocarbon dating, perhaps within a few decades. Warming at the beginning of the Holocene Interglacial may have taken place in two phases, during the first of which, from about 10 100 BP to possibly 9600 BP, marine temperatures seem to have been lower than at present, more especially on the east coast of Scotland and in southern Sweden. Full marine interglacial circulation may not have been established until 9500 BP. Water depth in the Faeroe–Shetland Channel may have been a major factor in controlling sea and air temperature from Scotland northwards during the Windermere Interstadial and Holocene Interglacial and, by implication, during earlier interglacials and interstadials.

scholarly journals Holocene uplift and palaeoseismicity on the Eliki Fault, Western Gulf of Corinth, Greece

1996 ◽  
Vol 39 (3) ◽  
Author(s):  
I. Stewart
Keyword(s):  
Radiocarbon Dating ◽  
Tectonic Activity ◽  
The West ◽  
The Past ◽  
Gulf Of Corinth ◽  
Two Phases ◽  
Coastal Uplift

Radiocarbon dating of elevated coastal phenomena along the emergent footwall of the Eliki Fault in the West- em Gulf of Corinth has established a chronology of tectonic emergence during Holocene times. The results confirm -6 m of coastal uplift over the last 3000 years at sites both immediately adjacent to, and more distant from, the offshore l'ault. Although revealing little or no spatial vm.iation along the fault, temporally the data de- fine two phases of enhanced tectonic activity (0-3000 year B.P. and pre- 7-8000 year B.P.) separated by a 4- 5000 year period of tectonic quiescence. Well documented historical surface faulting during the most recent lclive phase testify to the contribution to net uplift played by coseismic increments, but these are considered to be superimposed on significant aseismic movements. While asesismic uplift confuses the palaeoseismic .ecord, correlation of prominent notch levels with dated raised shoreline fauna provides evidence for at least 3 surface faulting events during the past 2500 years.

Observation of Studtite and Metastudtite on Spent Fuel

2002 ◽  
Vol 757 ◽  
Author(s):  
Bruce McNamara ◽  
Edgar Buck ◽  
Brady Hanson
Keyword(s):  
Nuclear Fuel ◽  
Spent Nuclear Fuel ◽  
Water Interface ◽  
Spent Fuel ◽  
Surface Corrosion ◽  
Air Water Interface ◽  
Extensive Surface ◽  
Two Phases ◽  
Fuel Particles ◽  
Short Times

ABSTRACTWe have characterized uranyl peroxide phases on commercial spent nuclear fuel (SNF) samples formed under immersion conditions. At short times, crystallites of metaschoepite were observed on the hydrated fuel particles. Over a two-year period, all evidences of metaschoepite disappeared and in many samples, the fuel particles appeared to be coated by a new alteration phase. Additionally, milligrams of corroded fuel aggregates were observed at the sample air-water interface in each sample. The corrosion phases on bulk fuel and on the suspended materials were examined by SEM, EDX, and XRD and were identified as studtite (UO4·4H20) and metastudtite (UO4·2H20), respectively. The reason for the partitioning of the two phases is unclear at this time. SEM micrographs of the bulk powders indicated extensive surface corrosion and fragmentation of particles.

scholarly journals ANU Radiocarbon Date List I

Radiocarbon ◽  
1967 ◽  
Vol 9 ◽  
pp. 15-27 ◽  
Author(s):  
H. A. Polach ◽  
J. J. Stipp ◽  
J. Golson ◽  
J. F. Lovering
Keyword(s):  
Radiocarbon Dating ◽  
Age Determination ◽  
Radiocarbon Date ◽  
Research Needs ◽  
Australian Aboriginal ◽  
Australian Institute ◽  
National University ◽  
The University ◽  
Sample Record ◽  
Interpretation Of Results

The Radiocarbon Dating Laboratory is installed in the Department of Geophysics and Geochemistry, Institute of Advanced Studies of the Australian National University. The Australian Institute of Aboriginal Studies has materially aided the establishment of the laboratory and is allocated a major proportion of the dating time over the next three years for samples in Australian Aboriginal archaeology. Beyond this the laboratory is to serve research needs within the University. To facilitate communication between collectors and laboratory a handbook on collection of specimens and interpretation of results has been prepared (Polach and Golson, 1966) and a radiocarbon sample record and an age determination sheet are in use.

scholarly journals Radiocarbon Dating of a Multi-phase Passage Tomb on Baltinglass Hill, Co. Wicklow, Ireland

2017 ◽  
Vol 83 ◽  
pp. 305-323 ◽  
Author(s):  
Rick J. Schulting ◽  
Meriel Mcclatchie ◽  
Alison Sheridan ◽  
Rowan Mclaughlin ◽  
Phil Barratt ◽  
...  
Keyword(s):  
Radiocarbon Dating ◽  
Human Bone ◽  
Cereal Grains ◽  
Wheat Grains ◽  
Plant Remains ◽  
Hazelnut Shell ◽  
Two Phases ◽  
Multi Phase ◽  
Hazelnut Shells ◽  
Calcined Bone

Baltinglass is a multi-chamber Neolithic passage tomb in Co. Wicklow, Ireland, excavated in the 1930s. This paper presents the results of a radiocarbon dating programme on charred wheat grains and hazelnut shell found underlying the cairn, and on cremated human bone found within and near two of the monument’s five chambers. The results are surprising, in that three of the six determinations on calcined bone pre-date by one or two centuries the charred cereals and hazelnut shells sealed under the cairn, dating to c. 3600–3400 calbc. Of the remaining three bone results, one is coeval with the charred plant remains, while the final two can be placed in the period 3300/3200–2900 calbc, that is more traditionally associated with developed passage tombs. A suggested sequence of construction is presented beginning with a simple tomb lacking a cairn, followed by a burning event – perhaps a ritual preparation of the ground – involving the deposition of cereal grains and other materials, very rapidly and intentionally sealed under a layer of clay, in turn followed by at least two phases involving the construction of more substantial chambers and associated cairns. What was already a complex funerary monument has proven to be even more complex, with a history spanning at least six centuries.

Precipitation of NiHfsi phase in NiAl single crystals containing Hf

1995 ◽  
Vol 53 ◽  
pp. 532-533
Author(s):  
A. Garg ◽  
R. D. Noebe ◽  
R. Darolia
Keyword(s):  
High Temperature ◽  
Single Crystals ◽  
High Temperature Strength ◽  
Bridgman Technique ◽  
Shell Mold ◽  
Third Phase ◽  
Unknown Phase ◽  
Transmission Electron ◽  
Two Phases ◽  
Nial Matrix

Small additions of Hf to NiAl produce a significant increase in the high-temperature strength of single crystals. Hf has a very limited solubility in NiAl and in the presence of Si, results in a high density of G-phase (Ni16Hf6Si7) cuboidal precipitates and some G-platelets in a NiAl matrix. These precipitates have a F.C.C structure and nucleate on {100}NiAl planes with almost perfect coherency and a cube-on-cube orientation-relationship (O.R.). However, G-phase is metastable and after prolonged aging at high temperature dissolves at the expense of a more stable Heusler (β'-Ni2AlHf) phase. In addition to these two phases, a third phase was shown to be present in a NiAl-0.3at. % Hf alloy, but was not previously identified (Fig. 4 of ref. 2 ). In this work, we report the morphology, crystal-structure, O.R., and stability of this unknown phase, which were determined using conventional and analytical transmission electron microscopy (TEM).Single crystals of NiAl containing 0.5at. % Hf were grown by a Bridgman technique. Chemical analysis indicated that these crystals also contained Si, which was not an intentional alloying addition but was picked up from the shell mold during directional solidification.

Imaging of Al-Li-Cu alloys with a Scanning Ion Microprobe

1990 ◽  
Vol 48 (2) ◽  
pp. 314-315
Author(s):  
K.K. Soni ◽  
D.B. Williams ◽  
J.M. Chabala ◽  
R. Levi-Setti ◽  
D.E. Newbury
Keyword(s):  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Equilibrium Phase ◽  
Icosahedral Symmetry ◽  
Ion Microprobe ◽  
X Ray ◽  
Cu Alloys ◽  
Two Phases ◽  
The University ◽  
Secondary Ion

In contrast to the inability of x-ray microanalysis to detect Li, secondary ion mass spectrometry (SIMS) generates a very strong Li+ signal. The latter’s potential was recently exploited by Williams et al. in the study of binary Al-Li alloys. The present study of Al-Li-Cu was done using the high resolution scanning ion microprobe (SIM) at the University of Chicago (UC). The UC SIM employs a 40 keV, ∼70 nm diameter Ga+ probe extracted from a liquid Ga source, which is scanned over areas smaller than 160×160 μm2 using a 512×512 raster. During this experiment, the sample was held at 2 × 10-8 torr.In the Al-Li-Cu system, two phases of major importance are T1 and T2, with nominal compositions of Al2LiCu and Al6Li3Cu respectively. In commercial alloys, T1 develops a plate-like structure with a thickness <∼2 nm and is therefore inaccessible to conventional microanalytical techniques. T2 is the equilibrium phase with apparent icosahedral symmetry and its presence is undesirable in industrial alloys.

Defect structures of Nb1+αS2 sulfidation scales

1992 ◽  
Vol 50 (1) ◽  
pp. 38-39
Author(s):  
Chuxin Zhou ◽  
L. W. Hobbs
Keyword(s):  
Stacking Faults ◽  
Rhombohedral Structure ◽  
Stacking Sequence ◽  
Defect Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plane Normal ◽  
Lower Case ◽  
Sulfur Layer ◽  
Two Phases

One of the major purposes in the present work is to study the high temperature sulfidation properties of Nb in severe sulfidizing environments. Kinetically, the sulfidation rate of Nb is satisfactorily slow, but the microstructures and non-stoichiometry of Nb1+αS2 challenge conventional oxidation/sulfidation theory and defect models of non-stoichiometric compounds. This challenge reflects our limited knowledge of the dependence of kinetics and atomic migration processes in solid state materials on their defect structures.Figure 1 shows a high resolution image of a platelet from the middle portion of the Nb1+αS2 scale. A thin lamellar heterogeneity (about 5nm) is observed. From X-ray diffraction results, we have shown that Nb1+αS2 scale is principally rhombohedral structure, but 2H-NbS2 can result locally due to stacking faults, because the only difference between these 2H and 3R phases is variation in the stacking sequence along the c axis. Following an ABC notation, we use capital letters A, B and C to represent the sulfur layer, and lower case letters a, b and c to refer to Nb layers. For example, the stacking sequence of 2H phase is AbACbCA, which is a ∼12Å period along the c axis; the stacking sequence of 3R phase is AbABcBCaCA to form an ∼18Å period along the c axis. Intergrowth of these two phases can take place at stacking faults or by a shear in the basal plane normal to the c axis.

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