Enhancing shared facilities for archaeological science at the University of Arizona

加强亚利桑那大学考古科学共享设施

• 批准号: 1625738
• 负责人: Charlotte Pearson
• 金额: $ 20.01万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2018-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1625738&HistoricalAwards=false
• 关键词: Enhancing; shared; facilities; archaeological; science

This award will fund the purchase of a scanning micro X-Ray Fluorescence (Micro-XRF) spectrometer for dendrochemical and other research. The research it enables is significant because it permits scientists to reconstruct multiple aspects of past environments and environmental change over time. Many species of trees add a visibly distinct ring of wood each year. The width of the annual ring may vary substantially from year to year, and these patterns of variation may be sufficiently distinctive to allow wood from a given site to be dated by comparison to a master chronology for the region. Dendrochronology was first developed at the University of Arizona in the 1930's. Once dated, the rings may be used to reconstruct variation in the factors controlling ring width. These include annual rainfall, annual temperature (at high altitude), the frequency of forest fires, and in which region the tree grew. A relatively new science is dendrochemistry - the study of variation in chemical composition from ring to ring within a tree. This award will allow researchers at the University of Arizona to undertake novel dendrochemical research on the enormous archive of cores from modern and ancient wood in the University of Arizona's Laboratory of Tree Ring Research (LTRR). The instrument will also be a valuable tool for LTRR'S outreach work with visiting high school science classes.The instrument will be installed in LTRR. A priority will be the search for evidence in dated tree rings of former volcanic eruptions and major forest fires, both of which result in spikes of certain chemical elements that are then taken up by growing trees. Since volcanic eruptions often spread ash (microtephra) over a very large area, they offer a potentially valuable means of correlating archaeological and paleoenvironmental sequences across a large region. Dendrochemical analysis by micro-XRF potentially offers a quick and efficient means of detecting and dating these past eruptions. An estimated 30-40,000 wood samples in LTRR cannot currently be assigned a cutting date because the outer ring is indistinct. Pilot research has however shown distinctive chemical changes at the heartwood/sapwood junction in several species, and also in the penultimate ring. Micro-XRF will be used to scan currently undated cores to look for these signals, from which cutting dates can be derived. This research can potentially make available many more dated samples for archaeological and paleoenvironmental interpretation.

该奖项将资助购买扫描微型X射线荧光（Micro-XRF）光谱仪用于树木化学和其他研究。 它使研究具有重要意义，因为它使科学家能够重建过去环境和环境变化的多个方面。许多种类的树木每年都会增加一个明显不同的年轮。年轮的宽度可能每年都有很大的不同，这些变化模式可能足够独特，可以通过与该地区的主要年表进行比较来确定来自特定地点的木材的年代。树木年代学最早是在20世纪30年代由亚利桑那大学发展起来的。 一旦确定日期，年轮就可以用来重建控制年轮宽度的因素的变化。 这些因素包括年降雨量、年气温（高海拔地区）、森林火灾的频率以及树木生长的地区。 树木化学是一门相对较新的科学，它研究树木年轮之间化学成分的变化。 该奖项将使亚利桑那大学的研究人员能够在亚利桑那大学树木年轮研究实验室（LTRR）的现代和古代木材核心的巨大档案中进行新颖的树木化学研究。该仪器也将成为LTRR与访问高中科学课的外联工作的宝贵工具。该仪器将安装在LTRR中。 一个优先事项将是在以前的火山爆发和重大森林火灾的树木年轮中寻找证据，这两种情况都会导致某些化学元素的激增，然后被生长的树木吸收。由于火山爆发经常在一个非常大的区域传播火山灰（microtephra），它们提供了一个潜在的有价值的方法，在一个大的区域内将考古和古环境序列相关联。通过微XRF进行树木化学分析可能提供一种快速有效的方法来检测和测定这些过去的喷发。 由于外圈不明显，LTRR中估计有30- 40，000个木材样本目前无法指定切割日期。然而，初步研究表明，在几个物种的心材/边材交界处，也在倒数第二个环独特的化学变化。 Micro-XRF将用于扫描当前未注明日期的岩心，以寻找这些信号，从中可以得出切割日期。 这项研究可能为考古和古环境解释提供更多的过时样品。