Abstract Eastern Africa is a key region for studying archaeological, palaeontological, and ecological movements. This region hosts critical developments in hominin and human evolution, the dispersal of food-producing populations across the continent, and some of the largest known contemporary mammalian migrations on the planet. Strontium isotope analysis of biominerals such as tooth enamel, eggshell, and other tissues in modern animals have been used to reconstruct migration, residential mobility, and provenience. The diverse geologies of Kenya and Tanzania, ranging from the Archaean Basement System rocks of the Tanzanian Craton to the recent volcanics of rift valleys, make it a highly promising area for mobility and provenience studies using strontium isotope ratios (87Sr/86Sr). Nevertheless, the application of strontium isotope analysis to reconstruct migration and individual mobility has been limited in the region due to the lack of a map predicting biologically available (bioavailable) 87Sr/86Sr. We present bioavailable 87Sr/86Sr data from a variety of modern and archaeological materials throughout Kenya and northern Tanzania. We show that 87Sr/86Sr of living organisms in the study area range from as low as 0.70439 for samples collected from Neogene volcanics to 0.72796 for samples collected from Precambrian Basement System rocks. We also present an 87Sr/86Sr map (isoscape) of Kenya and Tanzania developed using a machine-learning framework and a compilation of bioavailable 87Sr/86Sr data from Africa. This map provides the first predictions of bioavailable 87Sr/86Sr for East Africa, and represents a crucial resource for future work on ancient and modern animal and human mobility.

中文翻译：

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肯尼亚和坦桑尼亚北部生物可利用锶同位素比率 (87Sr/86Sr) 的空间变异：对生态学、古人类学和考古学的影响

摘要 东非是研究考古、古生物和生态运动的重要地区。该地区承载着古人类和人类进化的重要发展、整个大陆的粮食生产人口的分散以及地球上一些已知的最大的当代哺乳动物迁徙。现代动物的牙釉质、蛋壳和其他组织等生物矿物质的锶同位素分析已被用于重建迁移、居住迁移和起源。肯尼亚和坦桑尼亚的地质多样，从坦桑尼亚克拉通的太古代基底系统岩石到最近的裂谷火山岩，使其成为使用锶同位素比 (87Sr/86Sr) 进行流动性和来源研究的极有前景的地区。尽管如此，由于缺乏预测生物可利用 (bioavailable) 87Sr/86Sr 的地图，锶同位素分析在重建迁移和个体流动方面的应用在该地区受到限制。我们提供了来自肯尼亚和坦桑尼亚北部各种现代和考古材料的生物可利用 87Sr/86Sr 数据。我们表明，研究区生物的 87Sr/86Sr 范围从从新近纪火山岩收集的样品的低至 0.70439 到从前寒武纪基底系统岩石收集的样品的 0.72796。我们还展示了使用机器学习框架开发的肯尼亚和坦桑尼亚的 87Sr/86Sr 地图（isoscape）和来自非洲的生物可利用 87Sr/86Sr 数据的汇编。该地图提供了东非生物可利用的 87Sr/86Sr 的首次预测，