www.elsevier.com/locate/nimb

Nuclear Instruments and Methods in Physics Research B 249 (2006) 601–603

NIMBBeam Interactions

with Materials & Atoms

PIXE study on ancient pottery from Chinese Shanghai area

H.S. Cheng a,*, Z.Q. Zhang a, J. Song b, M.H. Gao c, D. Zhu a, J.W. Lin a, S.L. Feng d

a Institute of Modern Physics, Fudan University, 220 Handan Road, Shanghai 200433, Chinab Shanghai Museum, Shanghai 200003, China

c Department of Cultural Relics and Museology, Fudan University, Shanghai 200433, Chinad Laboratory of Nuclear Analytical Techniques, Institute of High Energy Physics, Chinese Academy of Science, P.O. Box 918,

Beijing 100039, China

Available online 11 May 2006

Abstract

Shanghai is the largest city in China, and it also has a very long history. Archaeologists have found that six thousand yeas ago, therewere ancient people living at Songze, Qingpu County, Shanghai. This paper reports the study of ancient potteries unearthed from theGuangfulin site located at Songjiang, Shanghai. The potteries unearthed from Guangfulin site belonged to two different culture types:the Liangzhu culture type (local culture) and a new culture, which might be derived from elsewhere. PIXE has been used to measure thechemical compositions of samples and factor analysis was used. Experimental results show that the compositions of the pottery from thetwo phases are different from each other. It means that the raw materials used to make the ancient pottery originate from different places.This results support the idea suggested by archaeologists that a group of ancient people migrated to the Shanghai area from some otherplace 4000 years ago.� 2006 Elsevier B.V. All rights reserved.

PACS: 32.30.Rj; 82.80.Ej; 91.65.Nd

Keywords: PIXE; Ancient pottery; Factor analysis; Source of raw material; Shanghai area; Interchange of pottery

1. Introduction

Shanghai is the largest city in China, and it also has avery long history. So far 18 sites of neolithic age in Shang-hai area had been scientifically excavated by archaeolo-gists. Among them are the Songze and Fuquan-shan hillslocated at Qingpu County, Shanghai. They are famousfor their oldest age and large quantities of important relicsunearthed. Dating shows that the aboriginals were living atSongze and Fuguan-shan hills 6000 years ago. This paperreports the PIXE study of the ancient potteries unearthedfrom the Guangfulin site, located at Songjiang, Shanghai.The Guangfulin site has been excavated three times since1999. In the excavated area, which extended over 546 m2,

0168-583X/$ - see front matter � 2006 Elsevier B.V. All rights reserved.

doi:10.1016/j.nimb.2006.03.064

* Corresponding author. Tel.: +86 21 65643460; fax: +86 21 65642787.E-mail address: hscheng@fudan.edu.cn (H.S. Cheng).

two kinds of remains were found. One was the Liangzhuculture type which was the local culture spreading aroundthe Tai lake. It is 4700–4800 years old [1]. The air distancefrom the Tai lake to Shanghai is about 130 km. Anotherwas a new culture which moved from an unknown placeand was called Guangfulin and is 4300 years old. The ques-tion is where these people came from. According to theexternal features of the pottery (the shape, the pattern onthe pottery), archaeologists believe that they were fromNorth China, for example, Shandong and Henan prov-inces, more than 1000 km away from Shanghai and sepa-rated by the Yangtze river. Four thousand years ago, agroup of ancient people migrated from North China toShanghai for some reason, and brought these potteries withthem. We hope to find scientific evidence for this hypothe-sis. A way to understand this problem is to determine theprovenance of the pottery. We have studied the interchangeof neolithic pottery amongst village sites in Chinese Sanxia

Fig. 1. A typical PIXE spectrum of an ancient pottery sample fromGuangfulin, Shanghai.

602 H.S. Cheng et al. / Nucl. Instr. and Meth. in Phys. Res. B 249 (2006) 601–603

area by PIXE [2]. If the chemical compositions of the twokinds of samples are different from each other, then we cancompare them with the ancient pottery samples fromNorthern Chinese sites to find the production area. In thisstudy, the improved external beam PIXE was used. Theelemental contents in the sample can be measured includinglight elements Na and Mg. This paper reports the experi-ment results.

2. Experimental

2.1. Sample preparation

Twenty-eight pieces of pottery were collected from thissite. Fifteen of them, labeled from S1 to S15, were fromthe Liangzhu culture layer which is 4700–4800 years old[1]. Thirteen of them, labeled from S16 to S28, were fromthe Guangfulin remains, which is 4310 ± 60 years oldaccording to the C14 dating by using AMS [3]. Most samplesare grey and fewer of them are red. Some of them are sandcontaining wares. To study the compositional relationshipbetween the Guangfulin pottery and the ancient potteryof North China, 12 pottery samples were collected fromthe Jingyanggang and Zouping sites, Shandong province.Their ages are close to those of Guangfulin pottery samples.

Samples for analysis were prepared by first ultrasoni-cally cleaning the sherds in pure water and drying themat a temperature of 100 �C. Second, they were put intoan agate mortar and lightly crushed. After that, weremoved the larger pebbles. Third, these samples werelightly ground and sifted through a sieve with 400 poresper square inch to remove the small sand grains. Last,the remaining powder was pressed into disks with a diam-eter of 15 mm and a thickness of 3 mm.

2.2. Experiments

The experiments were performed at the NEC 9SDH-23 MV pelletron tandem accelerator of Fudan University.In this study, the external beam PIXE was used. A3.0 MeV collimated proton beam with diameter of 1 mmwas extracted through a 7.5 lm thick kapton windowand traveled 10 mm in air before reaching the sample.The actual energy of protons reaching the samples was2.8 MeV as a result of energy loss in the kapton film andin air. An ORTEC Si(Li) detector (165 eV FWHM at5.9 keV) placed at 90� relative to the beam direction wasused to detect the X-rays emitted from the sample. Theangle between the beam direction and the normal to thesample is 45�. The distance between the beam spot anddetector was 15 mm. In this study, helium enveloped thepath from the target to detector. It makes it possible todetect the light elements Na and Mg. The beam currentwas the 0.05–0.1 nA with a dead time of less than 5%.From the measured spectrum the major and minor chemi-cal composition and trace elements in the sample could beobtained using the de-convolution program GUPIX-96 [4].

3. Experimental results

Fig. 1 shows a typical PIXE spectrum from a sample.From Fig. 1 we can see the peaks from Mg, Al, Si, P, K,Ca, Ti and Fe. From the measured PIXE spectrum of sam-ples the chemical compositions in the samples wereobtained by using the de-convolution program GUPIX-96. In this study, the reference samples whose chemicalcompositions were determined by ICP were used to checkthe experimental accuracy. Table 1 shows the comparisonof chemical contents measured by PIXE and ICP for refer-ence sample GSD6, which is made from stream sediment.The estimated uncertainty for PIXE measurement is listedin the table. From the table, it can be seen that the contentdifferences between the standard datum and that fromPIXE are less than 5% for MgO, Al2O3, SiO2, K2O,CaO, TiO2 and Fe2O3. For Na2O, P2O5 and MnO, theuncertainties measured by PIXE are larger, and they areabout 20%, 15% and 20%, respectively. The measuringerror for MnO mainly results from statistical error, becauseits counts are always low, which is related to its very lowconcentrations. From the PIXE measurement the contentsof nine major and minor element compositions (Na2O,MgO, Al2O3, SiO2, P2O5, K2O, CaO, TiO2 and Fe2O3)and nine trace elements (Co, Ni, Cu, Zn, Ga, Rb, Sr, Yand Zr) were obtained.

Fig. 2 shows the results for a factor analysis performedon chemical compositions. From the diagram 1, we can seethese samples are distributed into three groups. The newculture type potteries occupy the right part, while theJingyanggang and Zouping potteries from Shangdong sitat the left part, and the Liangzhu culture type samples staybetween them, respectively. There is one sample from Lian-gzhu culture type scattering into the new culture potteriesarea. Up the right of Fig. 2 there are two samples whosechemical compositions are different from others. For exam-

Table 1The chemical composition measured by PIXE for reference sample (wt%)

Na2O MgO Al2O3 SiO2 P2O5 K2O CaO TiO2 MnO Fe2O3 LOI

PIXE datum 2.8 ± 0.6 2.9 ± 0.1 14.8 ± 0.7 60.9 ± 0.6 0.20 ± 0.03 2.5 ± 0.1 3.7 ± 0.2 0.81 ± 0.04 0.12 ± 0.02 5.7 ± 0.3 5.38Standard datum 2.32 2.98 14.27 61.22 0.23 2.43 3.85 0.78 0.13 5.85 5.38

Fig. 2. The diagram of factor analysis from the chemical compositions inthe samples measured by PIXE. (1) Liangzhu culture type pottery fromGuangfulin site, Shanghai. (2) New culture type pottery from Guangfulinsite, Shanghai. (3) Jingyanggang pottery samples from Shandong. (4)Zouping pottery samples from Shandong.

H.S. Cheng et al. / Nucl. Instr. and Meth. in Phys. Res. B 249 (2006) 601–603 603

ple the contents of Al2O3 are 24.6% and 26.1%, respec-tively, apparently higher than the average contents Al2O3

of other samples (18 wt%). Their external features are alsodifferent from other samples because of their white color,

and so they are named ‘‘white pottery’’. The color resultedfrom the lower contents of Fe2O3 in the samples: only 2%,which is much lower than the average of 5.95%. The whitepotteries were found in North China and made 4000 yearsago and have not been seen in Liangzhu cultural remains.Fig. 2 shows us that the chemical compositions of the sam-ples from Jingyanggang and Zouping are not the same asGuangfulin samples. So it seems that the new culture typepotteries of Guangfulin were not from there. We need tocollect more ancient pottery samples from other sites andcompare the chemical compositions to determine theirprovenance.

4. Conclusion

We have compared the chemical compositions of twokinds of pottery samples unearthed from Guangfulin site.The results show the raw materials used to make theseancient potteries were from different places. This result sup-ports the idea suggested by archaeologists that a group ofancient people migrated to Shanghai area from some otherplace about 4000 years ago.

References

[1] J. Song, L.J. Zhou, J. Chen, Archaeology 36 (10) (2002) 31 (inChinese).

[2] B. Zhang, B.H. Pan, Z.Q. Zhang, et al., Nucl. Instr. and Meth. B 219–220 (2004) 26.

[3] The Experimental Report, Number 20003 and 20004 of AMSLaboratory, Peking University, 2000.

[4] J.L. Campbell, J.A. Maxwell, Gupix96, The Guelph PIXE Program,University of Guelph, Ontario, Canada, 1996.