Archaeological Chronology Development and the Old Wood Problem on the Northern Colorado Plateau

在美国国家科学基金会的支持下，罗纳德H.托纳、他的同事和学生们将研究科罗拉多西部和犹他州东部考古遗址放射性碳测年中的“老木”问题。旧木问题是指木炭中放射性碳（14 C）的测定结果明显早于木炭被发现的环境。五个因素可以使木柴的年代明显早于其考古或现代环境：1）人们倾向于使用枯木作为燃料; 2）枯树或死分支可能在其木材被用作燃料之前很久就已经死亡;三、树木死亡后的风化、腐烂或昆虫活动，会使许多外部年轮脱落，增加枯枝残材的年代与使用时间之间的差距;四、燃烧去除额外的外部年轮，会使差距进一步扩大;五、从木材年轮系列的内部测定年轮的年代，会使差距进一步扩大。 这些过程单独或一起操作，可能会在日期和木材使用之间产生超出放射性碳日期的不确定范围的差距，从而严重高估了所涉及场地的年龄。这个拟议中的项目使用放射性碳和树木年轮测年，以研究“老木”采购的史前和历史时期的职业解释西部科罗拉多和东部犹他州的影响。以前的研究表明，旧木材问题的严重程度在空间、环境和文化上都有所不同。通过在三个沿着环境梯度的地区收集大量样本，该项目将评估不同环境对薪材资源的年龄和可得性的影响。当地多物种多世纪树轮年表的建设将是特别重要的弗里蒙特，网关传统，尤特网站在西部科罗拉多和东部犹他州的约会，并可能是至关重要的了解弗里蒙特/尤特的关系和尤特人种。这个拟议的项目将帮助我们为这三个群体开发木材使用模型，并为遗址的年代确定提供解释性指导。因此，该项目的智力价值是测试放射性碳测年的环境变异性，为该地区创建新的树木年轮年表，开发文化木材使用实践的新模型，并评估技术变革作为这些地区遗址放射性碳测年的一个因素。该项目将在西部科罗拉多和东部犹他州的弗里蒙特、门户传统和尤特考古学之外产生更广泛的影响。它将为理解全世界干旱和半干旱环境中的放射性碳测年和木材使用实践做出重要贡献。该项目还将有助于研究生和本科生的培训和发展。它也可能有助于校准其他计时技术，如考古磁学和热释光测年，并完善史前弗里蒙特和史前和早期历史的乌特陶器类型的陶瓷系列研究。它将改进木材使用的模型，这可能对理解技术变革对木材资源开发的影响有影响。

With the support of the National Science Foundation, Dr. Ronald H. Towner, colleagues and students will examine the 'old wood' problem in radiocarbon dating of archaeological sites in western Colorado and eastern Utah. The old wood problem is the tendency for radiocarbon (14C) determinations from wood charcoal to be significantly older than the contexts in which the charcoal is found. Five factors can make firewood dates significantly earlier than their archaeological or modern contexts: 1) the tendency of people to use dead wood for fuel; 2) a dead tree or dead branch may have died long before its wood was used for fuel; 3) weathering, decay, or insect activity after tree death can remove many exterior rings and increase the gap between the date of the deadwood remnant and the time of its use; 4) removal of additional exterior rings by burning can further expand the gap; and 5) dating rings from the inner part of the wood's ring series widens the gap still further. Operating singly or together, these processes can produce a gap between date and wood use that exceeds the uncertainty range of radiocarbon dates and thereby seriously overestimate the age of the site involved. This proposed project uses both radiocarbon and tree-ring dating to examine the impacts of 'old wood' procurement on interpretations of the prehistoric and historical period occupations of western Colorado and eastern Utah. Previous research indicates that the magnitude of the old wood problem varies spatially, environmentally, and perhaps culturally. By collecting abundant samples in three areas along an environmental gradient, the project will assess the impacts of different environments on the age and availability of fuelwood resources. The construction of local multi-species multi-century tree-ring chronologies will be particularly important for dating of Fremont, Gateway Tradition, and Ute sites in western Colorado and eastern Utah, and may be critical in understanding Fremont/Ute relationships and Ute ethnogenesis. This proposed project will help us develop wood use models for the three groups and provide interpretive guidelines for dating the sites. Thus, the intellectual merit of the project is to test environmental variability of radiocarbon dates, create new tree-ring chronologies for the area, develop new models of cultural wood use practices, and evaluate technological change as a factor in radiocarbon dating of sites in these areas.This project will have broader impacts beyond the Fremont, Gateway Tradition, and Ute archaeology in western Colorado and Eastern Utah. It will make important contributions toward the understanding of radiocarbon dating and wood use practices in arid and semi-arid environments worldwide. The project will also contribute toward graduate and undergraduate student training and development. It may also contribute to calibration other chronometric techniques, such as archaeomagnetism and thermoluminescence dating, and to refining ceramic seriation studies of prehistoric Fremont and protohistoric and early historic Ute pottery types. It will refine models of wood use that may have implications for understanding the impacts of technological change on the exploitation of timber resources.