Growth process in an elephant tusk: Age estimations based on temporal variations in bomb-radiocarbon content

In this study, 14C analysis by accelerator mass spectrometry (AMS) was applied to age estimation based on temporal variations in bomb-produced-14C contents of a full elephant tusk registered at Kyushu University. The tusk measured 175 cm long and 13.8 cm in diameter at the root. Thirty tusk-fragment samples were used for 14C analysis with AMS to estimate the formation ages of different positions according to catalogued global 14C contents (F14C). The F14C value of the tip of the tusk suggested that the elephant was born around 1980, while that of the root suggested death around 1994, a lifespan of at least 14 years, rather shorter period than the average lifetime of an elephant (ca. 80 years). In addition, the F14C values of fragments collected along a cross-sectional line suggested that the outer part of the tusk formed first with inner parts being deposited gradually with growth.