Collaborative Research: Assessing the Impact of Holocene Climate Change on Bioavailable Strontium Isotope Ratios

圣母大学的Antonio Simonetti博士和普渡大学的Michele Buzon博士将研究气候变化对尼罗河流域近4000年来生物可利用锶的同位素特征的影响。该项目建立在两位主要研究人员之前的研究合作的基础上，这些研究人员主要根据考古动物群(土壤、动物、植物)和人类样本的锶同位素签名，确定了尼罗河流域埃及和努比亚遗址的移民模式和古代文明中的文化互动。这一首次详细调查的结果将准确追踪尼罗河流域内干燥气候所驱动的生物可利用锶区域分布的任何时间变化。这种方法将被证明对全球其他地区非常有用，在这些地区，最近的气候条件在感兴趣的考古时期发生了重大变化。土壤、生物和化石材料中的锶同位素因地区而异，利用同位素比率，科学家可以追踪个体在有生之年如何在地区之间流动。这个项目将提供关于环境因素是否可以改变单个地区的比率的见解。该项目将包括对研究生进行最先进的同位素技术培训，他们还将直接参与分析和解释结果。这项研究将包括美国苏丹考古研究中心(AmSARC)的参与，该中心的使命是鼓励美国和苏丹在苏丹的考古研究和合作。Simonetti和Buzon将通过测定尼罗河沿岸不同时期总共20个地点的动物、土壤、植物和人类样本的锶、铅和钕同位素特征，扩大调查样本的覆盖范围，并将这些结果与目前的同行进行比较。样品也将从世界各地相关博物馆的藏品中获得。评估尼罗河流域的生物可利用性锶还将依赖于综合两个私人投资机构从约250个标本中获得的现有锶同位素数据，这些标本包括从埃及(孟菲斯、古尔奈)和努比亚(谢拉尔、C组、法老、阿马拉西部、汤博斯、科尔马)遗址调查的考古人类和动物样本。这些综合结果将有助于表征同位素的可变性，并更好地理解这一地区的人类流动性，该地区社会政治转型和群体之间的接触丰富。从这个项目中获得的结果将有助于阐明过去约4000年来尼罗河流域内全新世气候变化的任何输入或影响。通过将动物群样本的考古或古锶同位素特征与今天的样本进行比较，我们的研究将更好地了解尼罗河流域内风成(风驱动的)贡献，如果有的话。这项拟议的研究将对考古学家进行基于同位素的全球古代迁徙调查具有重大意义，因为气候变化是贯穿地球历史的一种现象。对于尼罗河流域，这涉及到非洲湿润时期的干燥，这已经发生在我们星球的其他地区。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Dr. Antonio Simonetti, of the University of Notre Dame, along with Dr. Michele Buzon, of Purdue University, will investigate the impact of climate change on the isotopic signature of bioavailable strontium during the last ~4,000 years within the Nile River Valley. This project builds on previous research collaborations by both principal investigators that have established immigration patterns and cultural interactions in ancient civilizations for Egyptian and Nubian sites within the Nile River Valley based primarily on strontium isotope signatures of archaeological faunal (soil, animal, plant) and human samples. The results from this first time, detailed investigation will accurately trace any temporal change in the regional distribution of bioavailable strontium driven by a drying climate within the Nile River Valley. This approach will prove extremely useful for other regions around the globe where recent climatic conditions have changed significantly during the archaeological period of interest. Strontium isotopes in soil and living and fossil materials vary on a regional basis and using isotope ratios scientists can trace how individual during their lifetimes moved between regions. This project will provide insight into whether environmental factors can change ratios in a single area. This project will include training of graduate students in state-of-the-art isotope techniques, and they will also be directly involved in analyzing and interpreting results. This study will include participation of the American Sudanese Archaeological Research Center (AmSARC), which has a mission to encourage American and Sudanese archaeological research and collaboration in Sudan.Drs. Simonetti and Buzon will expand coverage of samples investigated by determining the strontium, lead, and neodymium isotope signatures of faunal, soil, plant and human samples from combined 20 sites along the Nile River occupied over various time periods, and compare these results to those from their present-day counterparts. Samples will also be obtained from collections of pertinent museums worldwide. Assessing the bioavailable strontium for the Nile River Valley will also rely on synthesizing existing strontium isotope data obtained by both PIs from ~250 specimens, which consist of both archaeological human and faunal samples investigated from Egyptian (Memphis, Qurneh) and Nubian (Shellal, C-Group, Pharaonic, Amara West, Tombos, Kerma) sites. These combined results will help to characterize the isotope variability and better understand human mobility in this region, which is rich with sociopolitical transitions and contact between groups. The results obtained from this project will help elucidate any input or influence of Holocene climate change within the Nile River Valley for the past ~4,000 years. By comparing archaeological or paleo-strontium isotope signatures of faunal samples to their present-day counterparts, our study will provide a better understanding of aeolian (wind-driven) contribution, if any, within the Nile River Valley. The proposed research will have major implications for archaeologists conducting isotope-based investigations of ancient migrations around the globe since climate change is a phenomenon that has occurred throughout Earth's history. For the Nile River Valley, this has involved a drying of the African Humid Period, which have taken place in other regions of our planet.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.