原始瓷的三种年代测定方法结果比较

采用常规的热释光细粒混合矿物法、热释光前剂量饱和指数法以及单片再生剂量光释光法三种测年方法,对中国上海、浙江萧山地区出土的7件西周、春秋、战国以及汉代的原始瓷样品进行了年代测定,并对测得的每个样品的3个年代结果与已知年代进行比对。用热释光细粒混合矿物法测定得到了较为理想的年代结果,与样品的已知年代结果相比吻合得较好。用热释光前剂量饱和指数法测定得到了该方法的上限饱和年代,即距今1800年左右。用再生剂量光释光法测定得到了这些样品的年代,只是实际年代的50％-80％左右,结果不太理想。因此,采用热释光细粒混合矿物法测定这类样品的年代,只要解决了制样问题,还是目前较好的测年方法。     

古陶瓷热释光测定年代发展

对古陶器热释光测定年代的两个标准方法——“细粒混合矿物技术”和“粗粒石英技术”作了详细的论述,介绍了这两个方法中古剂量和年剂量测量方法的发展和现状,对影响古剂量和年剂量测量准确性的一些复杂因素和解决的方法进行了分析,着重叙述了古瓷器热释光测定年代的新发展——“前剂量饱和指数法”。几十年的研究结果表明,热释光测定年代在古陶瓷真伪鉴定上已经取得了很大的成功,但是在年代测定的精确度和准确度上还不够,需要深入研究。     

热释光前剂量激活法与熄灭法测定瓷器年代 结果比较

为找到一个合适的测定不同时代烧制瓷器样品年代的热释光测年方法,用热释光前剂量熄灭法与前剂量激活法分别测定97个现代、民国、清代、明代、元代、宋代、五代以及唐代瓷器样品的古剂量。研究结果表明对现代、民国以及清代晚期烧制的瓷器样品采用热释光前剂量激活法测定,可以获得比热释光前剂量熄灭法更为准确的结果。对于清代中、早期、明代晚期的瓷器样品用两种方法测定的古剂量结果基本相同。但对于明代中、早期、元代、宋代、五代与唐代以及年代更长的瓷器样品,则采用热释光前剂量熄灭法测定可以得到较为满意的结果,而前剂量激活法无法用于这些年代较长的瓷器样品年代测定。因此,采用合适的热释光方法测定不同年代烧制的瓷器样品非常重要。     

上林湖越窑瓷器前剂量测定年代中的热激活特性(TAC)研究

利用热释光前剂量技术方法测定瓷器年代,须对瓷器样品进行热激活特性测试,以得到一个最高的测量灵敏度,来提高测定年代的精确度。为此,对慈溪上林湖及周邻地区的狗颈山、低岭头、开刀山、瓦片涯、大路口和寺龙口六处唐、五代与北宋古瓷窑遗址的60件瓷器样品进行热释光年代测量前,进行了热激活特性测定研究。结果表明,上林湖地区的越窑瓷器样品具有非常高的热释光灵敏度,以及比较一致的热激活特性及温度。其中样品的最高热激活温度为700℃,最低热激活温度为64℃,平均激活温度为658℃。在应用前剂量技术测定慈溪上林湖及周邻地区的越窑瓷器样品年代时,采用正确的热激活温度都可以得到一个相对比较准确、可靠的年代结果。     

不同热释光法测定洛阳唐三彩年代结果比较

采用前剂量法和细粒混合矿物技术法共测定了11件洛阳唐代、民国与现代三彩样品的年代,并对其结果进行了比较.用前剂量法测定11件洛阳三彩样品年代都得到了较好的结果,其中5件唐代洛阳三彩样品的测定年代都落在唐代年限范围内;5件烧制于1996年的仿唐代洛阳三彩样品的测定年代都在最近几十年范围内;一件民国仿唐代洛阳三彩样品的测定年代为距今114年.用细粒混合矿物技术法也测定了上述11件洛阳唐三彩样品的年代.其中5件洛阳唐代三彩样品中只有1件样品的测定年代结果落在唐代年限内;5件烧制于1996年的仿唐代洛阳三彩样品的测定年代都在最近二十年范围内,得到了较好的结果.一件民国仿唐代洛阳三彩样品的测定年代为距今882年,其结果显然是错误的.因此,选择合适的热释光方法测定洛阳唐三彩器物的年代非常重要.     

上海博物馆实验室开展古代陶器、瓷器热释光真伪鉴定服务

上海博物馆文物保护与考古科学实验室从１９７５年开始从事古代陶瓷热释光测定年代研究。１９８４年从英国引进了牛津Ｌｉｔｔｌｅｍｏｒｅ公司的７１１型热释光装置,１９９７年又从丹麦引进了国际上最先进的ＲｉｓφＴＬ／ＯＳＬ－ＤＡ－１５型的全自动热释光／光释光测定年代系统。经过二十多年的研究,积累了丰富的经验,不仅建立了国际上通用的标准细粒（ｆｉｎｅ－ｇｒａｉｎ）技术和前剂量（ｐｒｅ－ｄｏｓｅ）技术,还为测定瓷器年代专门研究出“前剂量饱和指数法”新技术。对被鉴定的每件陶器和瓷器用一种或两种方法进行年代测定,…     

陶器古剂量线性回归方法和误差评估

陶器古剂量P包含等效剂量Q和超线性修正I两个部分,为了提高古剂量测量的准确性,正确地计算古剂量的测量误差,本工作测试了10个古陶片样品,利用线性回归方法计算等效剂量Q和超线性修正I,并对不同的古剂量计算方法进行误差分析和评估。研究表明,线性回归方法(包括归平法和平归法)计算陶器古剂量的准确性优于目前采用的常规法;通过几种不同方法的误差比较和分析,归平法所得误差较其它方法更严谨、合理。该研究在提高古剂量测量的准确性和正确计算古剂量的测量误差两方面具有重要的意义,使得古剂量的测量更加合理,符合数理统计规律。     

晚清议改科举新探

废除科举并非清统治者的初衷。迄道光至光绪,长达半个多世纪,议改科举的主流,多以讲求实学、增广科目、取材标准多样化为基本取向,希望以老树嫁接新枝的方法,激活科举制生机。朝臣疆吏们先后至少有18份以上要求增设科目的改革方案,正式奏呈清廷,最高执政者亦并多次谕令部院大臣讨论议复。由于整个统治集团的观念更新滞后,礼部等机构恪守夷夏之大防,阻挠变制,总理衙门鉴于反对派势大而采取等待姿态,经济特科的举办又一波三折,以虎头蛇尾告终,使得科举制失去了逐步内在更新的最佳时机,后起者不得不考虑除旧布新的彻底变革。     

前剂量饱和指数法测定瓷器热释光年代

该成果根据“前剂量饱和指数法”原理,对前剂量饱和指数法测定古剂量的方法进行了重要的理论推导和大量的实验研究工作,首次将该方法成功地应用于中国古代瓷器的真伪鉴别和年代测定,为古瓷器热释光测定年代开创了新的局面。     

瓷器热释光测定年代研究

本工作从标准的(即线性的)前剂量技术着手,研究了瓷器热释光测定年代的方法。在这个研究中,发现了瓷器的灵敏度对剂量的非线性响应和灵敏度随剂量变化的指数模式。因此,一个用饱和指数拟合的方法被提了出来。实验表明,这是一个测定瓷器年代的成功方法。另外,还对一些与测定年代有关的复杂因素进行了讨论。例如,当少数瓷器的灵敏度与剂量不呈指数关系时,就要改变拟合模式或采用B的平均值方法等。     

THERMOLUMINESCENCE DATING OF POTTERY: AN ASSESSMENT OF THE DOSE-RATE FROM RUBIDIUM

The naturally occurring radioisotope ⁸⁷Rb 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 from ⁸⁷Rb. In fine-grain dating the omission of the ⁸⁷Rb 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 least 15%.     

SUPRALINEARITY CORRECTIONS IN FINE-GRAIN THERMOLUMINESCENCE DATING: A RE-APPRAISAL

Supralinearity correction in the routine ‘fine-grain’ technique of thermoluminescence dating of pottery has previously been regarded as empirical, but can now be shown to depend in many cases upon the previous radiation history of the material. The likely impact of this effect upon ceramic and bronze dating is considered and illustrated.     

METHODOLOGICAL DEVELOPMENTS IN THE LUMINESCENCE DATING OF BRICK FROM ENGLISH LATE‐MEDIEVAL AND POST‐MEDIEVAL BUILDINGS*

Fired clay brick samples, obtained from a group of seven high‐status late‐medieval and post‐medieval buildings in England ranging in age from c. ad 1390 to 1740, were dated by the luminescence method using an optically stimulated luminescence (OSL) technique. The results obtained indicate that, when applied to quartz extracted from brick, the technique is capable of producing dates that are in consistently good agreement with independent dating evidence for the buildings. For six samples taken from a group of four dating ‘control’ buildings the mean difference between the central values of luminescence and assigned ages was 5 ± 10 years (SD, n = 6). The methodology used is appropriate for application to other standing buildings in other temporal and geographic regions, and may be used with confidence where conventional dating methods are less certain. The study also examines the luminescence characteristics of quartz and the characteristics of the lithogenic radionuclides in brick samples and identifies various aspects related to the assessment of experimental uncertainty in testing the reliability of the method.     

THERMOLUMINESCENT DATING OF NEOLITHIC AND CHALCOLITHIC POTTERY FROM SITES IN CENTRAL PORTUGAL

Samples of Neolithic and Chalcolithic pottery from nine sites in the Upper Alentejo and Estremadura regions of Portugal have been dated by the thermoluminescence method (quartz inclusion technique). The project was designed to help establish an absolute chronology for the Neolithic and Chalcolithic periods in this area, and to try to elucidate the chronological relationships between settlement sites and burial sites (‘dolmens’) in the same area. Portugal was confirmed, together with Brittany, as being one of the earliest foci of megalith builders.     

Comparison of three K-feldspar luminescence dating methods for Holocene samples

The luminescence dating of the K-feldspar fraction is an alternative way for samples that cannot yield reasonable equivalent dose (D_e) from quartz fraction with very weak luminescence signal. For testing the reliability of the infrared stimulated luminescence (IRSL) dating of K-feldspar, luminescence dating was applied to quartz and K-feldspar fractions respectively for several Holocene samples in this study. K-feldspar apparent ages using routine single aliquot regenerative-dose (SAR) protocol, K-feldspar ages using g value correction method and ages from isochron dating method were compared with quartz ages. It is found that the g value correction method cannot give reliable ages due to the large errors induced during measurements. The isochron dating method is effective to the sample with problematically external dose rate. However, isochron dating may introduce a relatively greater error during grain sizes — D_e curve fitting, therefore this method could obtain low-resolution ages for Holocene samples. Even K-feldspar apparent age from routine SAR protocol is relatively younger by about 10% than the quartz age, it still could establish reasonable chronological framework for Holocene samples.     

How flakes shatter: a critical evaluation of quartz fracture analysis

Despite its worldwide use as a stone tool raw material, quartz is known to be a difficult material for archaeologists. The main reason for this is the tendency of quartz flakes to fragment during detachment, which complicates the use of traditional lithic analyses. In this article we present an experimental study of quartz flake fragmentation. We evaluate the method called fracture analysis that has been developed and used explicitly for the study of quartz assemblages. The method assumes high predictability of quartz flake fragmentation, but our experiments show that there is significant variation in fragmentation that fracture analysis does not take into account. Our results indicate that this variation is partly explained by indenter hardness, the relative thickness of the detached flake, as well as individual knapper-related factors. These results undermine the applicability of quartz fracture analysis in its current form. In addition, we discuss the effects of flake fragmentation on the technological organisation of prehistoric quartz users and suggest that it has affected reduction strategies as well as blank and tool dimensions. We also suggest that there should be mobility-related differences in archaeological assemblages in terms of the quality of the quartz raw material and that the curation of quartz should be low in relation to better quality raw materials used parallel with it.     

Thermoluminescence age of quartz xenocrysts in basaltic lava from Oninomi monogenetic volcano, northern Kyushu, Japan

We determined the eruption age of basaltic rocks by application of thermoluminescence (TL) method, which is often used for TL dating, to quartz. Mafic magma only rarely includes quartz because of their mutual disequilibration. The basaltic lavas reported herein include quartz as xenocrysts, as corroborated by their rounded or anhedral shape. The basaltic lava used for this study is from the Oninomi monogenetic volcano in northern Kyushu, Japan. The volcano eruption was estimated as occurring 7.3–29 ka because the lava exists between two widespread tephras: Aira-Tanzawa ash (26–29 ka) and Kikai-Akahoya ash (7.3 ka). We succeed-ed in collecting ca. 200 mg of quartz by decomposition of 30 kg of the lava samples. TL measurements for the lava indicate the eruption age as 15.8 ± 2.5 ka, which is fairly consistent with the stratigraphical estimation. Although the TL method has played a considerable part in constraining the timescale of Quaternary events, its application has been limited to silicic samples. The present result demonstrates the availability of quartz for dating even of mafic rock.     

A combined visual-geochemical approach to establishing provenance for pegmatite quartz artifacts

A technique for establishing source provenance for pegmatite quartz artifacts was developed using a quarry sample from the Churchill River basin of northern Manitoba and Saskatchewan. Secondary ion mass spectrometry (SIMS) was used to quantify Ti, Ge, Th, and U trace element concentrations and Pb isotope ratios, coupled with qualitative visual characteristics to distinguish between pegmatite quartz from different archaeologically exploited sources in the Churchill River basin region. The technique was also applied to a small sample of quartz artifacts recovered from sites in and around the study area in a preliminary attempt to assign or rule out raw material provenance to characterized sources.     

Different approaches to date bricks from historical buildings

The application of Thermally (TL) and Optically (OSL) Stimulated Luminescence on bricks used as building material has allowed solving an chronological issue in the field of historical building dating. The possibility to use one or more methodologies of dating is closely related to the luminescent and granulometric characteristics of the sample. Using some brick samples collected in the church of Sain Seurin in Bordeaux (France), this paper discusses the implications and the possibility to use different approaches and techniques for dating. With this aim luminescence measurements were performed on both polymineral fine grain and quartz inclusion phases extracted from each brick. For Equivalent Dose (ED) and consequently age determination, TL on mixed fine grain fraction (FG), OSL on quartz inclusions (QI) and on mixed fine grain (FG*) fraction, were used. The results obtained suggest the advantage of using OSL technique on fine grain fraction cleaned up by IR stimulation (FG*), but the use of quartz inclusion represents indeed a good alternative.     

OPTICAL DATING OF SINGLE AND MULTIPLE GRAINS OF QUARTZ FROM JINMIUM ROCK SHELTER,NORTHERN AUSTRALIA: PART I,EXPERIMENTAL DESIGN AND STATISTICAL MODELS*

Jinmium rock shelter is famous for the claims made by Fullagar et al. (1996) for the early human colonization and ancient rock art of northern Australia. These claims were based on thermo-luminescence ages obtained for the artefact-bearing quartz sediments that form the floor deposit at the site. In this paper, we outline the background to the optical dating programme at Jinmium, and describe the experimental design and statistical methods used to obtain optical ages from single grains of quartz sand. The results, interpretations, and implications of this dating programme are reported in a companion paper (Roberts et al. 7999, this volume).