ISSN:0003-813X    

DOI:10.1111/j.1475-4754.1978.tb00206.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

Previous comparisons of the radiocarbon dates of tree‐ring‐dated bristlecone pine samples and historicallydated samples from Egyptian archaeological sites have led to conflicting conclusions regarding the validity of the bristlecone pine calibration of radiocarbon dates. However, the new statistical analysis presented in this paper shows that the bristlecone pine calibration of the radiocarbon time‐scale is not incompatible with the given Egyptian historical chronology in the period 3000–300 B.C. (calendar years). This analysis is the first to allow for possible additional variability in the radiocarbon dates of short‐lived samples (due to short‐term fluctuations in the atmospheric carbon‐14 level), and to examine the effect on the analysis of any changes in the precision ascribed to the historical dates of the samples. Furthermore, the paper examines the reasons for the conflicting conclusions obtained in previous analyses, and uses the differences in the paired radiocarbon dates on the Egyptian samples to investigate the overall repeatability of these radiocarbon

ISSN:0003-813X    

DOI:10.1111/j.1475-4754.1978.tb00207.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

Archaeologists, along with other Quaternary researchers, seldom rely upon a single radiocarbon determination to provide an estimate of the age of the phenomenon which is the object of their study. There is an evident need for an explicitly formulated procedure for comparing sets of radiocarbon determinations from the same and from adjacent strata or sites, and for combining these where statistical and archaeological criteria indicate that this combination is warranted. The present contribution provides explicit modelling for a series of recommended procedures, a critique of previous methods, and paradigms for application of the recommended procedures.

ISSN:0003-813X    

DOI:10.1111/j.1475-4754.1978.tb00208.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

Radiocarbon measurements have been performed on a 250 year ‘floating’ tree‐ring section recovered from an archaeological site in north‐east Scotland. Short term fluctuations in atmospheric concentration appear to be superimposed on a general trend of decreasing ambient14Cparallel with tree growth. The most significant finding is the range of dates obtained from the sequence, namely 400 years, since it implies that the error on a single radiocarbon date is considerably greater than at present accepted on the basis of analytical precisio

ISSN:0003-813X    

DOI:10.1111/j.1475-4754.1978.tb00209.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

Among the manifestations of radioactive decay which can be etched to optical visibility on the surface of mica are tracks from nuclei recoiling from alpha emission, called ‘alpha‐recoil tracks’. If, beforeetching, the mica is heated to temperatures of the order of 600°C, all evidence of these tracks is annealed from muscovite mica in a few minutes. Alpha activity observed on mica from pot sherds, from stones surrounding fire places, from fire pits, and fired daub may constitute an alpha‐recoil track clock which started at the moment of the last firing of the a

ISSN:0003-813X    

DOI:10.1111/j.1475-4754.1978.tb00210.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

Oaxacan urns, the most characteristic esthetic expression of Zapotec culture in ancient Mesoamerica, are an important potential source of information for archaeologists and art historians, but relatively few exist with specific archaeological context and many are suspect as forgeries. This paper reports the thermoluminescent authenticity determinations of over one hundred Oaxacan urns as a first step toward confirmining a sequence previously determined by stylistic analysis. We tested a collection of 117 urns on loan to the St Louis Art Museum, mostly acquired after 1960, and another group of 6 from the Peabody Museum, Harvard, acquired before 1930. Our hypothesis that more recent collections would contain fewer forgeries was confirmed and a number of stylistic criteria for determining authenticity are critically examined in the light of the results.

ISSN:0003-813X    

DOI:10.1111/j.1475-4754.1978.tb00211.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

Lower Palaeolithic artefacts are frequently contained in fluviatile deposits, and it follows that a consideration of the stream processes which resulted in their deposition and preservation is necessary in order to evaluate the archaeological significance of such ‘assemblages’. This note indicates some aspects of artefact taphonomy of particular importance, in the hope that it may stimulate a more empirical approach to the contextual study of implement gro

ISSN:0003-813X    

DOI:10.1111/j.1475-4754.1978.tb00212.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

The assumption of isotropic etching in hydrofluoric acid of quartz grains prepared for thermoluminescence dating has been tested by optical and scanning electron microscopy. We have found that the rate of etch is very irregular over the surface of many grains and that some grains are attacked much more severely than others. The uncertainty introduced into TL dating by this effect is discussed.

ISSN:0003-813X    

DOI:10.1111/j.1475-4754.1978.tb00213.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

Alpha activities measured for four quartz extracts indicate that, in some samples, the alpha dose‐rate to the quartz due to radioactivity within the quartz can be significant. Uranium mapping of the quartz by neutroninduced fission tracks shows that the radioactivity is not homogeneously distribute

ISSN:0003-813X    

DOI:10.1111/j.1475-4754.1978.tb00214.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

The naturally occurring radioisotope87Rb makes a small contribution to the total dose‐rate. Assuming an average potassium:rubidium ratio of 200:1 the contribution is estimated at 2.9% of the B dose‐rate From potassium. The effect will be negligible in quartz inclusion dating because of the strong attenuation of the B‐ emission from87Rb. In fine‐grain dating the omission of the87Rb contribution will overestimate the age of a pottery sherd by not more than 2% and this is regarded as of minor importance when the total error in the technique is at le

ISSN:0003-813X    

DOI:10.1111/j.1475-4754.1978.tb00215.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY