ISSN:0003-813X    

DOI:10.1111/j.1475-4754.1973.tb00072.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

ABSTRACTSA statistical approach to the display of sets of14C dates is suggested. All available dates of any particular culture are used to calculate the two quartiles and the median dates for it. The ‘dispersion’of the dates is then displayed as a bar showing the extreme dates, the quartiles and the median; thus neither individual dates nor their standard deviations are shown. This ‘dispersion diagram’saves much space when the dates of several cultures are to be displayed.The argument is developed that the inter‐quartile range, which does not change very much when new dates become available and are added to the set, is a good index of the time span during which a culture flourished, and this range should normally be quoted rather than the mean, median or extreme dates of the culture. With samples of nine or more it can be shown by the Hypergeometric Distribution that there is a 97% chance of two cultures being different if their inter‐quartile ranges just fail to overlap, so that this method of display is useful in assessing the overlap of cultures. The fact that the dispersion diagram contains within it a measure of the statistical uncertainties of the individual estimates and therefore can replace the standard deviation of each individual14C date i

ISSN:0003-813X    

DOI:10.1111/j.1475-4754.1973.tb00073.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

ABSTRACTSA thermoluminescent (TL) glow‐curve peak occurs around 110°C for the mineral quartz. Its sensitivity may be changed by application of a radiation dose (termed thepre‐dose) followed by a heating of the quartz to 500°C: heating alone causes no sensitivity change. The enhancement observed (measured relative to the sensitivity of the peak prior to heating) is a measure of the magnitude of the pre‐dose.For quartz extracted from pottery the sensitivity enhancement induced by laboratory heating records anaturalpre‐dose, i.e. the accumulated dose experienced during archaeological burial. The latter quantity is used in TL age‐determination and a test programme is reported on the application of the pre‐dose dating method to sites covering the Roman era in Britain forward to

ISSN:0003-813X    

DOI:10.1111/j.1475-4754.1973.tb00074.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

ABSTRACTSThe application of the recently developed thermoluminescent method of pre‐dose dating to thirty‐seven glazed ceramics, purporting to have been manufactured during the T'ang Dynasty in China (a.d.618–906), is reported. The modern origin of eight of these pieces is established. The remaining twenty‐nine authentic pieces are discussed with respect to the accuracy of dating possible for such wares.The criterion for authenticity judgement commonly used for this material, that of glazecrackleur, is discussed critically and shown to be of only limited reli

ISSN:0003-813X    

DOI:10.1111/j.1475-4754.1973.tb00075.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

ABSTRACTSA new X‐ray fluorescent analyser is described which uses a miniature X‐ray tube or radioisotope source as alternative means of primary excitation. The advantages of this approach as compared to previous methods, particularly where elements low in the periodic table are concerned, is discussed.The second part of the paper describes an application of the technique. The non‐destructive analysis of valuable ceramics, where elements low in the periodic table are important for differentiation purposes, has previously presented a problem. By using the ‘Isoprobe’such measurements are possible. In this instance the separation of early Chinese porcelains into Northern and Southern production groups is shown to be possible. Although samples have been ground from the wares for comparison with optical emission spectrometry, it is shown that analysis of the unglazed portions of the pots themselves gave simila

ISSN:0003-813X    

DOI:10.1111/j.1475-4754.1973.tb00076.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

ABSTRACTSThe use of Mossbauer effect spectrometry as a tool to study iron‐bearing materials in works of art is introduced. A large range of pigments containing iron has now been surveyed. In addition, some interesting conclusions concerning the distinction between two types of terracotta is presented. The method, which can be applied completely non‐destructively, has great potential for purposes of identification and authenticat

ISSN:0003-813X    

DOI:10.1111/j.1475-4754.1973.tb00077.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

ABSTRACTSThe forms of inhomogeneity in metals and their origins are discussed in relation to the significance of analysis in an archaeological context. Particular consideration is given to the inhomogeneity that can arise from the redistribution of solutes during the solidification of an alloy casting.

ISSN:0003-813X    

DOI:10.1111/j.1475-4754.1973.tb00078.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

ABSTRACTSIn the neutron activation analysis of museum specimens, for which sampling is not permitted, corrections must be applied to measured activities to take into account the sample shape and its position relative to the detector. Correction factors are derived for samples of cylindrical shape such as segmented faience beads and a model technique is suggested for those of irregular shape such as flint and obsidian implements. These techniques used in gamma‐ray spectrometry with lithium‐drifted germanium detectors enable elemental concentrations to be determined from the measured count ra

ISSN:0003-813X    

DOI:10.1111/j.1475-4754.1973.tb00079.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

ABSTRACTSAn obsidian source can exhibit considerable variations in chemical composition. One such flow at Borax Lake in Lake County, California has been carefully investigated by neutron activation analysis of specimens from a number of different loci. It was found that the variable elements were completely coherent, and thus judgements concerning provenience could be just as definitive as with extremely homogeneous materials.

ISSN:0003-813X    

DOI:10.1111/j.1475-4754.1973.tb00080.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

ABSTRACTSTwo samples of obsidian projectile points from northwestern Nevada, one surface collected and the other excavated, were subjected to obsidian hydration measurement. The temporal ordering of the three projectile‐point types in each of the two samples was demonstrated to be the same on the basis of their hydration measurements. The validity of this temporal ordering of the projectile‐point types in the two samples was confirmed by the stratigraphic sequence of the types in the excavated sample.We have found that surface‐collected obsidian artifacts can be relatively dated by hydration measurement. In northwestern Nevada they hydrate at a rate almost double that of their excavated typological counterparts, but their relative ordering remains the

ISSN:0003-813X    

DOI:10.1111/j.1475-4754.1973.tb00081.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY