scholarly journals Freiberg Radiocarbon Measurements I

Radiocarbon ◽  
1970 ◽  
Vol 12 (1) ◽  
pp. 40-45
Author(s):  
Wolfgang Burkhardt ◽  
Hajo Stechemesser ◽  
Dietrich Mania

This list reports the first age determinations carried out by the Freiberg Radiocarbon Dating Laboratory. The preparation of samples and radiocarbon dates were done by the first two authors, who constructed the apparatus; sample descriptions and interpretations of dates were made by the third author.

Radiocarbon ◽  
2009 ◽  
Vol 51 (3) ◽  
pp. 977-986 ◽  
Author(s):  
Christopher M Wurster ◽  
Michael I Bird ◽  
Ian Bull ◽  
Charlotte Bryant ◽  
Philippa Ascough

We present accelerator mass spectrometry (AMS) radiocarbon dates on several organic fractions isolated from tropical guano deposits recovered from insular Southeast Asia. Differences were observed between 14C measurements made on bulk guano as well as bulk lipids, the saturated hydrocarbon fraction, solvent-extracted guano, and insect cuticles extracted from the same bulk sample. We infer that 14C dates from the bulk lipid fraction and saturated hydrocarbon fractions can be variably contaminated by exogenous carbon. In contrast, 14C measurements on solvent-extracted guano and isolated insect cuticles appear to yield the most robust age determinations.


Radiocarbon ◽  
2014 ◽  
Vol 56 (1) ◽  
pp. 181-187 ◽  
Author(s):  
Chunhai Li ◽  
Yongxiang Li ◽  
George S Burr

In order to test the accuracy of accelerator mass spectrometry (AMS) radiocarbon dating of pollen, 8 samples of pollen concentrates and 4 bulk organic samples were collected and analyzed from trench T1041 at the Tianluoshan site, Yuyao city, Zhejiang Province. This site was chosen because a reliable chronology had been previously established there based on radiocarbon dates of plant materials. The pollen concentrate samples were measured using AMS 14C and the 4 bulk organic samples were measured by liquid scintillation counting (LSC). The pollen concentrates and bulk organic samples yield ages that are a few hundred years to thousands of years older than those from plant materials, respectively. Contributions from reworked sediments can explain the older ages for the pollen concentrates and sediment organic dates. This study suggests that caution must be exercised when discussing millennial- or centennial-scale climate events based on chronologies that are controlled by age determinations of pollen concentrates.


1960 ◽  
Vol 26 ◽  
pp. 1-36 ◽  
Author(s):  
H. Godwin

The Somerset Levels are a submerged landscape. The valleys between the Mendip and the Polden Hills extend to 90 feet (27 metres) below Ordnance Datum, and they are filled to approximately the height of present sea-level by a soft blue-grey clay deposited in brackish water. Radiocarbon dating of material from Burnham-on-Sea shows that the marine transgression had been almost completed by 4300 B.C. (Q 134), and a date from Tealham Moor places the final transition to fresh-water conditions about 3500 B.C. (Q 120) (Godwin and Willis, 1959). As fresh water accumulated upon the almost level surface of the recent clay, reed-swamp dominated by Phragmites communis and Cladium mariscus occupied the whole region, building up coarse, loose-textured peat to a thickness of 1 or 2 metres. In the normal course of hydrarch succession (possibly enhanced by a climatic turn towards dryness), the reed swamps were invaded by fen-woods of alder and birch. These were extremely widespread at a time given by the first tentative radiocarbon dates as within the third millennium B.C.About 2000 B.C. there now began to develop within these fen woodlands an entirely different vegetation type, primarily composed of Sphagnum moss, cottongrass (Eriophorum spp.), ling (Calluna vulgaris), associated ericoid plants, and deer-grass (Trichophorum caespitosum). These communities quickly built up a complex of large raised bogs such as are now familiar around the Solway and the Central Irish plain, and of which Flander's Moss is a good Scottish example. These are gently domed structures rising a few metres above the level of the immediately surrounding land and relying almost entirely upon precipitation for their water supply.


Author(s):  
Sérgio Monteiro-Rodrigues

Recentemente obtiveram-se cinco novas datações pelo radiocarbono para as ocupações holocénicas do sítio pré-histórico do Prazo. Quatro delas apresentam resultados compatíveis com os já divulgados em publicações anteriores. No conjunto, dispõe-se agora de uma série de vinte e seis datações 14C que seconsideram válidas. Estas datações permitem remeter a fase que se atribuiu ao Epipaleolítico para os finais do X/ meados do IX milénio cal BC; o Mesolítico mais antigo para o terceiro quartel do VIII milénio cal BC; o Mesolítico final para o período compreendido entre o segundo quartel do VII milénio cal BCe os meados do VI milénio cal BC; e o Neolítico Antigo para o intervalo balizado entre os finais do VI milénio cal BC e um momento indeterminado posterior ao terceiro quartel do V milénio cal BC. Entre estes períodos com ocupações humanas observam-se intervalos temporais para os quais não existem datações absolutas. Sugere-se que este facto possa estar relacionado com as dinâmicas sedimentares do local no decurso do Holocénico e não necessariamente com um padrão de povoamento caracterizado pela descontinuidade. New radiocarbon dating for the Holocene occupations of the prehistoric site of Prazo (Freixo de Numão, Vila Nova de Foz Côa, Northern Portugal) - Recently, five new radiocarbon dates for the Holocene occupations of the prehistoric site of Prazo were obtained. Four of them show results that are consistent with those previously published. At the moment, there are twenty-six 14C dates that are considered to be valid. These dates assign the supposed Epipalaeolithic to the end of the 10th/ middle of the 9th millennium cal BC; the earliest Mesolithic to the third quarter of the 8th millennium cal BC; the late Mesolithic to the interval between the second quarter of the 7th millennium cal BC and the middle of the 6th millennium cal BC; and the early Neolithic to the interval between the end of the 6th millennium cal BC and an undetermined moment after the third quarter of the 5th millennium cal BC. Among these periods with human occupation there are intervals for which there is no absolute dating. It is suggested that this may be related to the sedimentary dynamics of the site during the Holocene and not necessarily to a settlement pattern characterized by discontinuity.


Radiocarbon ◽  
1986 ◽  
Vol 28 (3) ◽  
pp. 1200-1205 ◽  
Author(s):  
Cecilio Gonzalez-Gomez ◽  
Purificacion Sanchez-Sanchez ◽  
Elena Villafranca-Sanchez

The following list includes some measurements made from December 1982 to May 1985 in the Radiocarbon Dating Laboratory, Faculty of Science, University of Granada, of samples from Spain, Portugal, and the Sudan. Sample preparation techniques and benzene synthesis remain as described previously (R, 1982, v 24, p 217–221) and equipment and measurement of samples was also reported previously (R, 1985, v 27, p 610–615). Radiocarbon ages are calculated using the 14C half-life of 5570 years and 0.95 activity of NBS oxalic acid is used as modern standard. Sample descriptions are based on information provided by submitters. Age determinations were made with the help of Research Project 0925/81, CAICYT, Spain.


2016 ◽  
Vol 14 (1) ◽  
pp. 83-98 ◽  
Author(s):  
Elena A.A. Garcea ◽  
Hong Wang ◽  
Louis Chaix

The study area presented in this paper comprises two geographical entities in northern Upper Nubia located between the Second and the Third Cataract of the Nile River: Sai Island and the Amara West district, on the present left bank of the river. Four sites, three at Sai Island and one in the Amara West district, were excavated. They represent three distinct archaeological complexes, named Arkinian, Khartoum Variant, and Abkan, which encompass a long time period from ca. 11,000 to 6000 cal years BP (9000–4000 BC) and range from late foraging to early pastoralism. Accelerator mass spectrometry (AMS) radiocarbon dating was applied to multiproxy materials in order to provide a frame of reference for this important chronological and economic period in this area. Different types of materials were selected, namely wood charcoal, charcoal tempers in pottery, ostrich eggshell, and aquatic gastropod shells. Twenty-four new AMS radiocarbon dates are presented to (a) cross-check the accuracy and reliability of the chronology of late foraging and early pastoral sites in our study area; (b) integrate, update, and revise the previously available radiometric dates; and (c) reconstruct a comprehensive framework of the chronology of late foraging and early pastoralism in Upper Nubia.


2003 ◽  
Vol 68 (4) ◽  
pp. 719-735 ◽  
Author(s):  
William C. Prentiss ◽  
Michael Lenert ◽  
Thomas A. Foor ◽  
Nathan B. Goodale ◽  
Trinity Schlegel

This paper provides an analysis of radiocarbon dates acquired during earlier and recent field seasons at the Keatley Creek site, southern British Columbia. Results indicate that early occupations predating 1900 cal. B.P. occurred, but were not likely associated with population aggregation and large housepits. The aggregated village appears to have emerged by approximately 1700 cal. B.P. and was abandoned at approximately 800 cal. B.P. A break in the occupational sequence is recognized at 1450-1350 cal. B.P. and one other short break may have occurred shortly after 1250 cal. B.P. Peak socioeconomic complexity appears to have been achieved between 1350 and 800 cal B.P. Climatic warming may have provided a selective environment favoring population aggregation and intensification during this time. The final abandonment of the Keatley Creek village appears to have been part of a regional phenomenon suggesting the possibility that climatic factors were important in this case as well.


Radiocarbon ◽  
1995 ◽  
Vol 37 (2) ◽  
pp. 103-110 ◽  
Author(s):  
Anna Pazdur ◽  
Mieczysław F. Pazdur ◽  
Jacek Pawlyta ◽  
Andrzej Górny ◽  
Michał Olszewski

We report preliminary results of a long-term systematic study intended to gather paleoclimatic records from precisely dated speleothems. The research project is limited to speleothems deposited in caves of the Cracow-Wieluń Upland, the largest and best-explored karst region in Poland, covering ca. 2900 km2 with >1000 caves. Speleothem samples were selected from collections of the Geological Museum of the Academy of Mining and Metallurgy in Cracow. Radiocarbon dates of these samples from ca. 45–20 ka bp almost exactly coincide with age range of the Interplenivistulian. A break in speleothem formation between ca. 20 and 10 ka bp may be interpreted as a result of serious climatic deterioration associated with the maximum extent of the last glaciation. We observed differences among 14C, U/Th and AAR dating results. Changes of δ13C and δ18O in speleothems that grew between ca. 30 and 20 ka bp may be interpreted as changes of paleoclimatic conditions.


2002 ◽  
Vol 33 ◽  
pp. 9-19 ◽  
Author(s):  
David Mattingly ◽  
David Edwards ◽  
John Dore

AbstractThis short paper presents a full list of the currently available radiocarbon dates from the work of Charles Daniels in the 1960s-1970s and the Fazzan Project (1997-2001). The dates can be grouped into several categories, by site or area, and demonstrate the potential of radiocarbon dating being applied to historic-period archaeology in the Sahara. This complements earlier Italian work on later prehistory. One of the most important conclusions to emerge is that the construction of castle-like buildings in Fazzan began within the Garamantian period and that some of the numerous well-preserved mudbrick fortified sites are thus rather earlier than has previously been envisaged. A second important conclusion is that the use of AMS dating can help to identify and confirm activity of the post-Garamantian and early Islamic phases, which has hitherto been elusive.


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