Age Determination of Fossil Shell Samples from Southern Shores of Iran Using Radiocarbon Dating

Asgharizadeh, F; Salimi, B; Ghannadi Maragheh, M; Hojaghani, O

Age Determination of Fossil Shell Samples from Southern Shores of Iran Using Radiocarbon Dating

Document Type : Research Paper

Authors

F Asgharizadeh

B Salimi

M Ghannadi Maragheh

O Hojaghani

Abstract

In this study, the method of radiocarbon dating was applied to determine the age of fossil shell samples, obtained from southern shores of Iran. The radiocarbon (¹⁴C) dating method has been applied in many fields, including oceanography, geology, and archaeology. In this method the sample is pretreated in physical and chemical procedures,then using a Benzene Synthesis System, benzene (C₆H₆) is synthesized from the sample. One gram of the synthesized benzene is added into a teflon counting vial containing 12ml scintillator Hisafe3. In order to count and determine the radioactivity concentration of beta particles emitted from radiocarbon, the liquid scintillation counting method is applied. The age determination of fossil samples has been carried out by using count per minute (cpm) values from beta counting of ¹⁴C in synthesized samples comparing to the obtained results from Oxalic Acid Modern Standard. For 8 shell samples studied, the determined ages are in the range of 210-3890 years, according to Before Present (BP; before 1950). The efficiency of Liquid Scintillation Counting system for ¹⁴C is calculated to be about 92% and the calculation error for the low age samples was ±40 years and for the high age samples was ±100 years, respectively.

Highlights

H. Nada, B. Jadranha, “Measurement of low ¹⁴C activities in a liquid scintillation counter,” radiocarbon, 46 (1), 105-116 (2004).
H. Toyoizum, KH.A. Arslanove, M. Kato, K. Masuda, H. Miyahara, Y. Muraki, T. Murata, T. Uemura, “The application of radiocarbon techniques to environmental monitoring,” Proceeding of ICRC (2001).
M. Stuiver and P.D. Quay, “Atmospheric 14C changes resulting from fossil fuel CO₂ release and cosmic ray flux variability,” Earth plan. Sci. LETT, 53, 349-362 (1981).
E. Bard, B. Hamelin, R.G. Fairbanks, A. Zindler, “Calibration of the 14C time scale over the past 30000 years using mass spectrometric U-Th ages from Barbados corals,” Nature, 345, 405-410 (1990).
Mc Cormac, F.G, “Liquid scintillation counter characterization, optimization and benzene purity correction,” Radiocarbon, 37, 2, 593-599 (1992).
H. Kojola, H. Polach, J. Nurmi, Oikari, “High resolution low-level liquid scintillation beta- spectrometer,” Int. J. Appl. Rad. Isot, 35, 949-952 (1984).
M. Stuiver, H. Polach, “Discussion reporting of ¹⁴C data,” Radiocarbon, Vol. 19, No. 3 (1977).

Keywords

Radiocarbon Dating

Liquid Scintillation Counting

Archaeological Specimens

Carbon-14

Benzene

1. H. Nada, B. Jadranha, “Measurement of low ¹⁴C activities in a liquid scintillation counter,” radiocarbon, 46 (1), 105-116 (2004).
2. H. Toyoizum, KH.A. Arslanove, M. Kato, K. Masuda, H. Miyahara, Y. Muraki, T. Murata, T. Uemura, “The application of radiocarbon techniques to environmental monitoring,” Proceeding of ICRC (2001).
3. M. Stuiver and P.D. Quay, “Atmospheric 14C changes resulting from fossil fuel CO₂ release and cosmic ray flux variability,” Earth plan. Sci. LETT, 53, 349-362 (1981).
4. E. Bard, B. Hamelin, R.G. Fairbanks, A. Zindler, “Calibration of the 14C time scale over the past 30000 years using mass spectrometric U-Th ages from Barbados corals,” Nature, 345, 405-410 (1990).
5. Mc Cormac, F.G, “Liquid scintillation counter characterization, optimization and benzene purity correction,” Radiocarbon, 37, 2, 593-599 (1992).
6. H. Kojola, H. Polach, J. Nurmi, Oikari, “High resolution low-level liquid scintillation beta- spectrometer,” Int. J. Appl. Rad. Isot, 35, 949-952 (1984).
7. M. Stuiver, H. Polach, “Discussion reporting of ¹⁴C data,” Radiocarbon, Vol. 19, No. 3 (1977).