^<14>C concentration anomaly of land-snail for ^<14>C age determination in Kikai Island, Kagoshima Prefecture, south west Japan
Autor: | Takahashi, Syuichi, Wada, Hideki, Aoki, Hiroshi, Nakamura, Toshio |
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Jazyk: | japonština |
Rok vydání: | 1998 |
Zdroj: | 名古屋大学加速器質量分析計業績報告書. 9:201-211 |
Popis: | In order to estimate the ^C age anomaly of land-snail shells in Kikai Island, ^C concentration of modern shells and plant leaves were analyzed. The ^C analyses were carried out by on Benzene-Liquid Scintillation method for ordinary amount of samples and Accelerator Mass Spectrometry (AMS) method for small scale of samples. Modern leaves of two species were analyzed to estimate the ^C concentration of the atmosphere. The percentage of modern ^C concentration of leaves in the range of were from 114.3% to 112.3%, with an average of 112.7% with respect to the pre-bomb level. This value is consistent with the decreasing activity of the ^C concentration of the atomosphere. The percentage of modern ^C concentration of modern land-snail shells were variable in a range from 98.8% to 109.2%, from 111.8% to 115.9%, from 103.2% to 108.4% and 96.3%. ^C age anomaly for two land-snail shells were estimated from the difference of the percentage of modern ^C concentration between modern leaves and modern shells. ^C age anomaly for Bradybaena phaeogramma were in a wide range of 250-1060 yr. with average of 640±320 (yr.±1σ), -230-60 yr. with average of -110±150(yr. ±1σ) for Cyclophorus kikaiensis, 310-710 yr. with average of 450 ±220 (yr. ± σ) for Acusta despecta kikaiensis, 1260 yr. for Luchuena reticulate. The variation in ^C age anomaly of Bradybaena phaeogramma and Acusta despecta kikaiensis shells may be due to ther ingestion of dead carbon derived from the substrate of limestone. I could not detect the ^C age anomaly of Cyclophorus kikaiensis shells. It is interesting for biology that Prosobramchia, Cyclophorus kikaiensis shows no ^C age anomaly, but other species belong to Pulumonata show ^C age anomaly. タンデトロン加速器質量分析計業績報告 Summaries of Researches Using AMS 1997 (平成9)年度 |
Databáze: | OpenAIRE |
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