Japan Geoscience Union Meeting 2018

Presentation information

[JJ] Oral

S (Solid Earth Sciences) » S-GC Geochemistry

[S-GC46] Solid Earth Geochemistry, Cosmochemistry

Tue. May 22, 2018 10:45 AM - 12:15 PM 202 (2F International Conference Hall, Makuhari Messe)

convener:Gen Shimoda(Geological Survey of Japan, AIST), Katsuhiko Suzuki(Research and Development Center for Submarine Resources, Japan Agency for Marine-Earth Science and Technology), Katsuyuki Yamashita(岡山大学大学院自然科学研究科, 共同), Akira Ishikawa(Department of Earth Science and Astronomy, The University of Tokyo), Chairperson:Wakaki Shigeyuki(JAMSTEC), Ishikawa Akira(Tokyo Institute of Technology), Shimoda Gen(産業操業技術研究所)

10:45 AM - 11:00 AM

[SGC46-01] Strontium three isotope analysis of archaeological human bones: the effect of diagenetic alteration

*Shigeyuki Wakaki1, Hikari Mukumoto2, Masayo Minami3 (1.Kochi Institute for Core Sample Research, JAMSTEC, 2.Department of Environmental Sciences, Nagoya University, 3.Institute for Space-Earth Environmental Research, Nagoya University)

Keywords:Sr isotope ratio, archaeological sciences, diagenetic alteration, apatite, cremated human bones

Hydroxyapatite, a main inorganic component in bones, contains Sr at high concentration up to the order of several hundreds of ppm. Radiogenic strontium isotope ratio (87Sr/86Sr) of bone hydroxyapatites has been used to study residential mobility of ancient humans and mammals in archeological fields. Strontium in human body is derived from the background geological system via foods such as plants and animals. Therefore, 87Sr/86Sr value of bone hydroxyapatite directly reflects 87Sr/86Sr value of the bedrocks in the region where the foods came from.
Archeological human remains have been buried in soils for hundreds of years or more. There is a strong possibility that the buried human bones have been affected by diagenetic process and the original 87Sr/86Sr values of the bone hydroxyapatites have been changed by such secondary alteration. Although evaluation of the effect of possible diagenetic alteration is essential in reconstructing the residential mobility of ancient humans from the bone hydroxyapatite 87Sr/86Sr data, reactivity of bone hydroxyapatite during diagenetic processes is not well understood.
In this study, we attempt to make a quantitative evaluation of secondary alteration effect on the bone hydroxyapatite 87Sr/86Sr during diagenesis. Hydroxyapatite fractions were extracted from a cremated human remain of a Buddhist priest Jokei (AD1155-1213) and three different cremated bodies excavated from Middle age sites in Binman-ji, Shiga, Japan. Bulk soil samples from the excavation sites as well as exchangeable phases of these soils were also prepared. Both the radiogenic (87Sr/86Sr) and stable (δ88Sr/86Sr) isotope ratios were analyzed for these samples. The results will be discussed in the presentation.