British Museum Natural Radiocarbon Measurements I

Barker, Harold G.; Mackey, Carol J.

doi:10.1017/s0033822200020397

Cited by 32 publications

(14 citation statements)

References 11 publications

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“…Comment: date is within expected age range 1600 to 2400 B.C. based on previous series of Grimes Graves dates (Barker and Mackey, 1963 Manby (Manby, 1963 (Ashbee, 1958(Ashbee, , 1961 BM-134, 5180 + 150 (Barker and Mackey, 1968 (Barker and Mackey, 1961) and Hembury, 5100 + 150 (Barker and Mackey, 1963 (Pollard, 1966 (Wainwright, 1967(Wainwright, , 1968 (Barker and Mackey, 1963), P-382, 8956 ± 103 (Stuckenrath, 1963 (Trump, 1966; Barker and Mackey, 1968 and refs. (Barker and Mackey, 1968 …”

supporting

confidence: 62%

“…British IVlusezim Natural Radiocarbon Measurements VI 289 Ebbsfleet 4660 + 150 (Barker and Mackey, 1963 (Barker and Mackey, 1961 (Barker and Mackey, 1968). Date was much younger than expected (Oakley, 1963a, b) but is now confirmed by this measurement (Oakley et al, 1967).…”

mentioning

confidence: 67%

“…The gas counting measurements were carried out by the method and techniques previously described (Barker and Mackey, 1968) the only modifications being the replacement of some old electronic units by more stable solid-state equipment; proportional counting results are indicated in the text by (P) at the end of the relevant sample descriptions. Liquid scintillation counting, which is now the preferred method in this laboratory, is carried out using a Packard Tri-Carb liquid scintillation spectrometer model 3315/AES fitted with selected low-noise quartz-faced photomultipliers.…”

mentioning

confidence: 99%

“…Expected age late 6th millennium B.C. based on 6140 ± 150 Smith, 1964;Damon et al, 1963;Barker andMackey, 1959, 1961;Berger et al, 1965). More recently, Suess produced detailed plot of discrepancies from ca.…”

mentioning

confidence: 99%

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British Museum Natural Radiocarbon Measurements VI

1969

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Dates listed below are based on measurements made up to May 1968, and cover a period during which the technique of gas proportional counting using CO2 was gradually replaced by liquid scintillation counting using benzene. The gas counting measurements were carried out by the method and techniques previously described (Barker and Mackey, 1968) the only modifications being the replacement of some old electronic units by more stable solid-state equipment; proportional counting results are indicated in the text by (P) at the end of the relevant sample descriptions. Liquid scintillation counting, which is now the preferred method in this laboratory, is carried out using a Packard Tri-Carb liquid scintillation spectrometer model 3315/AES fitted with selected low-noise quartz-faced photomultipliers. Normally 3 ml of benzene is prepared from each sample. This is dissolved in 12 ml of scintillation grade toluene containing 5 gm/liter of scintillator (PPO) and the solution is measured in a standard low-potassium glass vial at a temperature of 0°C. Photomultiplier E.H.T., amplifier, and channel width settings are optimized for C14, and measurements are carried out at ca. 65% efficiency of detection for C14 to eliminate interference from any tritium which may be present in the benzene. Under these circumstances the background is approx. 8.6 cpm and the modern (95% A0X) is approx. 24.0 cpm. Samples are counted in groups of 3 to 5 together with background and modern reference samples and are measured for at least one week, the instrument being set to cycle at 100 min intervals. In this period, the counts accumulated are such that the background is always measured to a statistical accuracy of better than 1% and most other samples to a higher accuracy than this. Background and modern counts used in the calculation of each result are only those relevant to the period of measurement of that particular sample. Statistical analysis of groups of replicate measurements made under these conditions over a very long period of time has demonstrated the excellent long-term stability of the equipment and indicates that the technique is quite capable of achieving results of very high statistical accuracy when required.

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supporting

confidence: 62%

mentioning

confidence: 67%

mentioning

confidence: 99%

mentioning

confidence: 99%

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British Museum Natural Radiocarbon Measurements VI

1969

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“…der Wissenschaften (Felber, 1965(Felber, , 1966(Felber, , 1967(Felber, , 1968. As noticed in Felber, 1968, dates presented in Felber, 1965, 1967 have to be corrected because age of standard wood, used Suess (1954), W-82, 10,260 ± 200;W-84, 10,510 ± 180;Ostlund (1957a), St-18, 10,145 ± 370;Minnich (1957), H-105-87, 11,500 ± 300; de Vries, Barendsen and Waterbolk (1958), GrN-454, 10,995 + 250;Olsson (1959), U-20, 10,950 ± 130, U-75, 10,810 ± 140; Barker and Mackey (1959), BM-19, 11,333 ± 200;Tauber (1953) (Kral and Mayer, 1968). If date is corrected for de Vries-effect according to Suess's (Kral and Mayer, 1968).…”

Section: Introductionmentioning

confidence: 99%

Vienna Radium Institute Radiocarbon Dates I

Felber¹

1970

Radiocarbon

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A dating system consisting of gas sample counter with internal anticoincidence counter ring, transistorized electronic equipment, and chemical apparatus was developed in the Institute (Felber and Vychytil, 1962;Felber, 1965 (Felber, 1966). Stability of electronics and counter is checked once a day by taking the topmost part of the peak of Mna-X-rays following electron capture in Fe-55, radiated through a beryllium window. Checking is done with the same single channel analyzer (switched over to operation with small window) used for energy discrimination (switched over to two discriminator operation) during measurement. If any change should be observed, discriminator settings are corrected. Energy discrimination is not optimized (Felber, 1962) because a neutron generator using (d,t) reaction is run in the same building in which the samples are prepared: the lower discriminator is set above tritium maximum energy at 22 keV, the upper one at 120 keV, the highest possible energy absorption of C14 ,8 corresponding to a sample net counting rate giving a difference equal to three times its standard deviation in the same measuring time (Felber, 1962).

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The place beyond the trees: renewed excavations of the Middle Stone Age deposits at Olieboomspoort in the Waterberg Mountains of the South African Savanna Biome

Val

Peña

Duval

et al. 2021

Archaeol Anthropol Sci

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Olieboomspoort is one of the few rock shelters in the vast interior of southern Africa documenting pulses of occupation from the Acheulean until the end of the Later Stone Age. Revil Mason excavated the site in 1954 and attributed the large Middle Stone Age (MSA) lithic assemblage to his middle phase of the so-called Pietersburg Industry. Recent work at the site has focused on the Holocene layers, but little is known about the earlier phases of shelter use. Here, we provide some background to the shelter, give a history of past research and present initial results following renewed fieldwork at the site. The MSA deposits contain abundant lithic artefacts and ochre, and we present an initial description of these cultural remains. Palynological analysis reveals limited potential for palaeoenvironmental reconstructions, but some faunal remains indicate open grasslands. We dated two equid teeth that provided highly consistent combined U-series-ESR estimates, resulting in a mean age of 150 ± 14 ka (1σ). Even when considering potential sources of uncertainty such as variations in water-intake, these fossils can securely be dated to Marine Isotopic Stage 6. Our reappraisal of site formation processes highlights the fact that the archaeological assemblage is strongly time-averaged. We discuss these different results in the context of a recently rekindled interest in the so-called Pietersburg Industry.

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British Museum Natural Radiocarbon Measurements I

Abstract: The first series of radiocarbon dating measurements made at the British Museum Research Laboratory are reported in the following list. The report covers a period during which two instances of radioactive contamination occurred to interrupt dating work, and is consequently a short one.

Cited by 32 publications

References 11 publications

British Museum Natural Radiocarbon Measurements VI

British Museum Natural Radiocarbon Measurements VI

Vienna Radium Institute Radiocarbon Dates I

The place beyond the trees: renewed excavations of the Middle Stone Age deposits at Olieboomspoort in the Waterberg Mountains of the South African Savanna Biome

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