Beschreibung:
Abstract. Mammoth teeth have been widely investigated using stable-isotopic analysisfor paleoenvironmental and paleoecological reconstructions due to theirlarge size and frequent discoveries. Many past investigations sampled thetooth enamel with the “bulk” method, which involves drilling one sample fromthe occlusal surface to the root for each tooth. Some of the more recentstudies applied the “sequential” method, with a sequence of samples drilledfollowing the dominant enamel growth direction to produce a time series ofisotopic oscillations that reflects high-resolution environmental changes, aswell as changes in mammoth dietary behavior. Although both the bulk andmean sequential δ18O values are expected to represent theaveraged signal over the time of tooth formation, it is uncertain whethertheir paleoenvironmental records were formed during similar periods of time.In this study, we applied both sampling methods (sequential drilling firstfollowed by a thin layer of bulk drilling) on the same enamel ridges ofmultiple mammoth teeth and compared their respective δ18Ovalues. The results indicated that, in most enamel ridges, the bulk sampleshave more negative δ18O values compared to the averagesequential values, and some of the bulk values even fall outside the rangeof sequential values. The most likely explanation for the differences is thestructure and formation stages of enamel that caused uneven distributions ofdifferent seasons recorded in the samples. This finding provides insightsinto current limitations of the two sampling methods and the applicabilityof cross-method data comparison from past studies.