The region of present-day Angola was one of the main areas from which millions of enslaved Africans were abducted and forced to migrate to the Americas during the transatlantic slave trade. Strontium isotope (⁸⁷Sr/⁸⁶Sr) analysis is a useful tool in reconstructing large-scale human movements across geologically distinct landscapes in archaeological and forensic contexts. However, the absence of environmental ⁸⁷Sr/⁸⁶Sr reference data from Angola hinders the use of ⁸⁷Sr/⁸⁶Sr analysis in provenance studies related to Angola, especially in identifying the geographic origin of enslaved people in the African Diaspora. Here, we measured 101 plant samples from most, yet not all, major geological units to draft the first bioavailable ⁸⁷Sr/⁸⁶Sr map (isoscape) for Angola using a machine learning framework. Our results suggest that the ⁸⁷Sr/⁸⁶Sr ratios in Angola span a large range from 0.70679 to 0.76815 between the different geological units. Specifically, the high average ⁸⁷Sr/⁸⁶Sr ratios of 0.74097 (±0.00938, 1 SD) found in the Angola Block of central Angola, are distinctly more radiogenic than any previously published bioavailable ⁸⁷Sr/⁸⁶Sr ratios for western Central and West Africa. However, these match the ⁸⁷Sr/⁸⁶Sr ratios previously published for human enamel samples from four historic slavery contexts in the Americas. We demonstrate that our strontium isoscape of Angola greatly improves the ability to assess the possible origins of enslaved African individuals discovered outside of Africa and encourage the future use of emerging African isoscapes in the study of life histories within the slave trade.

现今的安哥拉地区是跨大西洋奴隶贸易期间数百万被奴役的非洲人被绑架并被迫迁移到美洲的主要地区之一。锶同位素 ( ⁸⁷ Sr/ ⁸⁶ Sr) 分析是一种有用的工具，可用于在考古和法医背景下重建大规模的人类活动，这些活动跨越不同的地质景观。然而，缺乏来自安哥拉的环境⁸⁷ Sr/ ⁸⁶ Sr 参考数据阻碍了⁸⁷ Sr/ ^86的使用与安哥拉有关的起源研究中的高级分析，特别是在确定非洲侨民中被奴役者的地理起源方面。在这里，我们测量了来自大多数（但不是全部）主要地质单位的 101 种植物样本，以使用机器学习框架为安哥拉起草第一张生物可用的⁸⁷ Sr / ⁸⁶ Sr 图（isoscape）。我们的结果表明，安哥拉的⁸⁷ Sr/ ⁸⁶ Sr 比率在不同地质单元之间跨越了从 0.70679 到 0.76815 的很大范围。具体而言，在安哥拉中部的安哥拉地块发现的⁸⁷ Sr/ ⁸⁶ Sr平均比率高达0.74097 (±0.00938, 1 SD)，其放射性明显高于之前公布的任何生物可利用性⁸⁷中非西部和西非的Sr/ ^{86 Sr 比率。}然而，这些与之前公布的美洲四个历史奴隶制人类牙釉质样本的⁸⁷ Sr/ ^{86 Sr 比率相匹配。}我们证明，我们的安哥拉锶等值图极大地提高了评估在非洲以外发现的被奴役非洲人的可能起源的能力，并鼓励未来在研究奴隶贸易中的生活史时使用新兴的非洲等值图。