Developing Quantitative Methods to Address Sediment Modification

该项目将研究古代考古沉积物中考古废物的化学成分，以寻找动物驯化发展和早期人类种群相关增长的线索。从地球化学的角度来看，考古遗址是一个高度动态的特征，是人类和自然沉积物和溶解成分的复杂和重叠的混合物。在过去的二十年中，数十项研究探索了这些丰富的地球化学记录，为人类行为和人类环境，空间利用以及动植物管理的许多方面提供了新的视角。然而，这些研究通常忽略了古代考古遗址的盐化学及其含义。这是一个错失的机会，特别是在一些干旱地区，在这些地区，占用后的修改可能是最小的，并且可能保留一些元素的封闭系统。本项目提出进一步发展一种新的方法来看待干旱土地考古遗址的地球化学作为一个整体，使用质量平衡模型。这种方法量化了一个系统中可溶性盐的添加和损失，以了解动物驯化的开始和进化。到目前为止的结果证明了这种模型方法在理解大约一千年时间跨度内土地利用强度和牲畜管理的变化方面的力量。垃圾中的盐化学成分主要是动物和人类的尿盐，它们在长期占据中稳步增加，这反映了人类和家养动物数量的扩大。该项目还将分析粪便生物标志物、古代肠道微生物群以及与现场人类和动物粪便相关的病原体（如沙门氏菌）。这将有助于更好地了解动物排泄物与古代病原体之间的关系，并提供有关疾病来源和传播的信息。该项目将支助培训三名早期职业科学家掌握各种地球化学和实地监测技术。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project will study the chemistry of archeological waste in ancient archaeological deposits for clues on the development of animal domestication and associated growth in early human populations. From a geochemical perspective, archaeological sites are highly dynamical features, a complex and overlapping mixture of human and natural sediments and dissolved constituents. Tens of studies over the past two decades have explored these rich geochemical records, providing a new perspective on many aspects of human behavior and human surroundings, their use of space, and plant and animal management. However, such studies have generally overlooked the salt chemistry of ancient archeological sites, and its implications. This is a missed opportunity, especially in some arid land sites where post-occupation modification can be minimal and closed-system retention of some elements is likely. This project proposes to further develop a new way of looking at the geochemistry of arid land archeological sites as a whole, using mass balance modeling. This approach quantifies soluble salt additions and losses to a system to understand the onset and evolution of animal domestication. Results so far demonstrate the power of this model approach for understanding changes in site-use intensity and livestock management over an approximately thousand-year time span.The salt chemistry of the refuse is dominated by animal and human urine salts, which increased steadily over the long term occupation, a reflection of expanding human and domesticated animal populations. The project will also analyze dung biomarkers, ancient gut microbiomes, and pathogens (e.g. Salmonella) that are associated with human and animal waste at the site. This should lead to a better understanding the relationship between animal waste products and ancient pathogens and provide information about disease source and spread. This project will support training of three early career scientists in a variety of geochemical and field monitoring techniques.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.