Collaborative Research
C. General Study on the Utilization of Dating Techniques for Research on Historical Materials
| Type of Research | Scientific Research |
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| Project Title | Scientific Study of Materials and General Chronological Research |
| Research Title | C. General Study on the Utilization of Dating Techniques for Research on Historical Materials |
| Head of the Research Team | IMAMURA Mineo |
| Research Period | 2006–2008 |
| Research Team |
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| Purpose | The purpose of this research is to discover multiple applications of scientific age determination methods for historical research. To be more precise, our objective is to apply AMS radio carbon dating or dendrochronology in empirical historical research, including that on buildings and structures, the organization of settlements and their remains, and in research on the Paleolithic Era and period of transition to the Jomon Era (including the environmental problems of such eras) in order to reveal the effectiveness of age determination and also to strengthen the age determination research base in the National Museum of Japanese History. |
2008
Progress
During the first half of this year, we have accumulated age determination test results from radio carbon dating and held two workshops concerning these results.
First Workshop Schedule: January 28, 2009 |
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Second Workshop Schedule: March 13, 2009 |
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Result
At the National Museum of Japanese History, research based upon Grants–in–Aid for Scientific Research has been conducted between 2005 and 2008 and our research was expected to be accepted as complementary research. However the majority of such aid resources were used for scientific research and our research was unable to display outstanding results when compared with other research. At least, the workshops on this research were able to encourage historians and archaeologists to use age determination in their researches. A portion of the age determination results obtained in connection with our pre–historical research will be exhibited in autumn, 2009. Following our research on the beginnings of the Yayoi Era, the starting points for the periods of ancient tomb creation were reorganized.
Above all, we are pleased to inform you that we were able to show the applications of natural scientific age determination for research on the "historical age" coming after immediately after the pre–historical period. The consistency of the periods determined though the use of characters, and writing, as well as writing methods and styles will be verified by improved precision in 14C dating. While examples of age determination remain insufficient, dating methods, for example, dendrochronology which does not, in principle, generate any errors, can be applied to those samples whose age is difficult to define.
2007
Progress
We carried out dendrochronology on materials used for Horyuji Temple which were exhibited at the Exhibition Hall of National Museum of Japanese History.
We held a workshop at the National Museum of Japanese History on September 1, 2007 and each researcher gave a presentation on the progress of his or her research. We conducted a roundtable discussion concerning how age determination should develop in the future along with our visit to the other exhibitions held on the same date.
We carried out 14C dating at Tokyo University for the statues collected from Chogakuji Temple, Ota City, Gunma Prefecture on September 24, 2007.
We examined framework members from an old folk house and collected samples for age determination in Hitachinaka City, Ibaragi Prefecture on October 15, 2007.
Result
With regards to the dendrochronology carried out on the materials from Horyuji Temple, we used a digital camera take photographs and analyzed these photos at the Nara National Research Institute for Cultural Properties. Outermost annual ring of both the wooden window frames and the Jidaruki (a wooden base rafter that extends outward from the roof framework) were found to date from around the year 620 A.D. From this, we were able to draw the conclusion that they had been used for construction after such time and we can estimate the date of construction based on this outcome.
We carried out 14C dating using the tandem accelerator at the Micro Analysis Laboratory of the University of Tokyo for the small quantity samples collected from the statue "Kaizan Eicho". We had some trouble with the determination and we need to analyze the test results, however the "susa" (a generic term for fibrous substances) used for the statue was found to date from the period between the Kamakura to Muromachi Eras.
In the process of materials–based age determination, it is necessary to focus on the results of the tests, but it is also important to demonstrate to historians and archaeologists that, through this research, age determination can be accomplished with a minimal amount of sample material (as in 14C dating) and without destroying the samples (through dendrochronology). From this point of view, the fact we were able to determine the dates of the historical materials is a valuable outcome.
However, as there are still many researchers who do not fully understand the purposes for which age determination can be employed, we must accomplish more in the future.
2006
Progress
We organized teams to focus on each research area, and then summarized all the results of their investigations and age determinations. We decided to hold a team meeting and research presentation in lieu of a general workshop at the end of year. With regard to the age determinations, preparations and purifications of the samples and graphite samples were conducted at our laboratory and radio carbon dating was conducted at another AMS institute. Some of the preparations and experiments were conducted at another private institution.
(1) We employed dendrochronology and 14C wiggle–match dating on 10 of the following samples—materials used in Horyuji Temple, Nijojo Castle and Senjyuji Temple held by Research Institute for Sustainable Humanosphere; and those used for Horyuji Temple held by Masaji Hamashima, honorary professor at our museum. In July, we undertook research on resources at the Research Institute for Sustainable Humanosphere and we held a meeting to review the research results. In February, we visited the storage room for viewing the historical samples of Horyuji Temple held by the National Museum of Japanese History.
(2) We undertook research on resources, collected samples and carried out age determinations using 14C dating at the Old Takahashi House (a historical farmhouse built in the middle of the Edo Era) which is designated as a nationally important cultural property in Saitama Prefecture. We also conducted age determination on building materials whose samples had been collected from four designated nationally important cultural properties, the Miki House in Fukuoka Prefecture, the Yoshimura and Izumi Houses in Osaka Prefecture and the Miki House in Tokushima Prefecture.
(3) We undertook field studies, the collection of samples and age determinations using 14C dating in connection with two temples, Kannon–ji Temple, Ushiku City, Ibaraki Prefecture and Hoenji Temple, Hikone City, Shiga Prefecture. With regard to the dates of construction and restoration, we compared our radio carbon dating results and the dates recorded for each temple.
(4) Dating on remains, including paddies, from the early and middle Yayoi Period. We conducted research on resources and sample collection from the Nakahara remains, Saga Prefecture and the settlements in Ogoori City, Fukuoka Prefecture. We are planning to carry out dating on these remains and settlements next year. Dating of the old column from the ancient tomb in Jyonoduka, Fukuoka Prefecture, we conducted research on resources and sample collection in December. We are planning to carry out dating on these samples next year. In regards to the settlements of Goshono, Iwate Prefecture, we carried out a study of the state of pit–dwellings buried over a short–term using age determination.
(5) We obtained documents and other materials of paper from the medieval period whose age can be determined by dating. We are planning to carry out radio carbon dating on these materials next year.
(6) We continued the age determination process on clay vessels dated mainly from early Jomon Era whose precise age remains unknown using radio carbon dating.
(7) Workshops and Research Presentations, etc.
International Symposium on Sustainable Humanosphere, 2006
| Schedule: December 21 Venue: Kyoto University, International Workshop Hall |
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Presenters:
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| Schedule: February 1 Venue: National Museum of Japanese History |
Presenters:
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The 4th Radio Carbon Workshop of the Japan Association for Quaternary Research
| Schedule: March 17 |
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Presenters:
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Result
Our research results are as follows:
a. In regards to the 10 samples, including those materials used in Horyuji Temple, we used both 14C wiggle–match dating and dendrochronology, and compared the outcomes. The results differed in almost all of the tests but these differences fell within the acceptable range except for those from one test. We need to examine this result more closely by considering the possible cause from two aspects, technical problems or environmental effects on the calibration curves. Some of the materials used for Horyuji Temple have proven to be very interesting research samples as they were found to have a much longer history than the historical records would suggest.
b. The Old Takahashi House was found to have been built at the beginning of the 18th century, The Hakogi House was built at the end of Kamakura Era (around the middle of the 14th century), the Miki House and the Yokoyama House were built in the first half of the 17th century, and the Izumi House was built in the latter half of the 17th century. Through comparison with the relevant property records it was also discovered that, the Old Takahashi and Yokoyama Houses had been constructed immediately after being moved to their present sites. According to the records, the Yoshimura House was rebuilt after the Osaka Natsu no Jin (the Summer Battle in Osaka) but its main building appears to have rebuilt much before this. This may be because certain materials were reused or converted for the rebuilding.
c. According to the temple’s records, Kannonji Temple was built in the Kamakura Era (from 1292 to 1334) although the oldest Munafuda (wooden plates blessed during invocations at the start of construction) state that Kannonji Temple was rebuilt in 1525. We have examined the original materials and other materials, including the Japanese lacquer, used for the Shumidan (a platform in the form of Mt. Sumeru, representing the highest point in the universe), of the adytum in the main hall using carbon 14 dating of in order to investigate the process of construction and restoration at Kannonji Temple. The sumidan was found to have been built during the 12th century while the original materials were dated to the 13th and 14th centuries. The style of the building and its worked wood suggest that this temple was built in Kamakura Era. In conclusion, we made the judgement to place the construction period in the Kamakura Era. The ages of the takekugi (bamboo nails) used for the parquet of the Buddha statue and the other construction components matched the repair records. The column from Hoenji Temple in Shiga Prefecture was found to have been built much earlier than the temple records indicated.
d. In regards to the chronology of early phase of the Jomon Era, we obtained dating ranges for the following: the early Jomon Era for the Maehara remains in Kagoshima Prefecture; posterior early Jomon Era for remains at Irienaiko in Shiga Prefecture (attachments to clay vessels); middle prophase of the Jomon Era for the Noda shell mound in Chiba Prefecture (carbonized shells remained inside a dwelling); the Kurohyoshiki Era for a house discovered in the Mizuki shell mound in Saitama Prefecture (carbonized wood); and the beginning of the early Sahashiki Era for the Mihiki shell mound in Ishikawa Prefecture (animal bones).
e. Due to budgetary restraints, the age determination of certain samples shall be postponed to the following year.
