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

北科罗拉多高原的考古年代学发展与老木问题

• 批准号: 1026422
• 负责人: Ronald Towner
• 金额: $ 13.63万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-15 至 2012-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1026422&HistoricalAwards=false
• 关键词: Archaeological; Chronology; Development; Old; Wood

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.

在国家科学基金会的支持下，罗纳德·H·汤纳博士、同事和学生将研究科罗拉多州西部和犹他州东部考古遗址放射性碳测年中的“老木”问题。老木材问题是从木炭中测定的放射性碳（14C）的趋势比发现木炭的环境要古老得多。有五个因素可以使柴火的年代明显早于考古或现代背景：1）人们倾向于使用枯木作为燃料； 2) 一棵枯树或枯枝可能在其木材被用作燃料之前就已经死亡； 3）树木死亡后的风化、腐烂或昆虫活动可以去除许多外部年轮，并增加枯枝残骸的日期与其使用时间之间的差距； 4）通过燃烧去除额外的外环可以进一步扩大间隙； 5)木环系列内部的约会戒指进一步拉大了差距。 这些过程单独或一起运行，可能会在日期和木材使用之间产生差距，超出放射性碳测年的不确定范围，从而严重高估相关地点的年龄。该拟议项目使用放射性碳和树木年轮测定法来研究“老木材”采购对科罗拉多州西部和犹他州东部史前和历史时期占领的解释的影响。先前的研究表明，旧木材问题的严重程度因空间、环境甚至文化而异。通过沿着环境梯度在三个区域收集丰富的样本，该项目将评估不同环境对薪材资源的年龄和可用性的影响。当地多物种、多世纪树木年表的构建对于科罗拉多州西部和犹他州东部的弗里蒙特、盖特威传统和尤特遗址的年代测定尤其重要，并且对于理解弗里蒙特/尤特关系和尤特民族起源可能至关重要。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，并为这些地点的年代测定提供解释指南。因此，该项目的智力价值在于测试放射性碳测年的环境变化，为该地区创建新的树木年轮，开发文化木材使用实践的新模型，并评估技术变化作为这些地点放射性碳测年的一个因素。该项目将对科罗拉多州西部和犹他州东部的弗里蒙特、盖特威传统和尤特考古学产生更广泛的影响。它将为了解全球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。它还可能有助于校准其他计时技术，例如考古磁学和热释光测年，以及完善史前弗里蒙特和史前和早期历史尤特陶器类型的陶瓷系列研究。它将完善木材使用模型，这可能有助于理解技术变革对木材资源开发的影响。