고고학 시료의 광(光) 여기(勵起) 루미네센스 연대측정

Age determination of archaeological samples using optically stimulated luminescence of quartz

석영이나 장석시료를 빛으로 여기시켜 검출된 루미네센스를 적당한 온도에서 관측하고, 관측된 루미네센스의 크기를 시간적으로 조절하면 고고학적, 지질학적 시료의 연대를 산출할 수 있다. 이 연구에서는 광 여기 루미네센스를 이용하여 한국에서 출토된 토기, 기와시료, 수전층 시료에 대한 연대를 측정하였다. 얻어진 광 여기 루미네센스 연대들은 고고학적 편년 뿐 만 아니라 방사성 탄소연대 결과와도 잘 일치하였다.

Controlled measurements of the optically stimulated luminescence signal from non-conducting, crystalline materials such as quartz and feldspar can provide a means of determining the time since the last heating of a pottery or the last exposure of a layer of sediment to sunlight, the age of the pottery or sediment, in a similar way to thermoluminescence dating. Whereas in the thermoluminescence dating of sediment only part of the latent thermoluminescence signal is bleached by sunlight as the sediment is deposited and allowance must be made during the laboratory measurements for the light insensitive component, optically induced luminescence dating has the advantage of working only with light sensitive traps in the crystal. Optical dating, using blue stimulation of quartz grains from archaeological samples, was undertaken. The dates obtained from the heated materials offered good agreement with the ages derived by typological assessment. Also, the ages of the bleached materials from a hydroponic farm were found to be in satisfactory results with those of radiocarbon dating in addition to a good stratigraphic correlation. We conclude that the optical dating used in here should contribute significantly to future archaeological dating work.