Experimental calibration of stable isotope and REE partitioning in bioapatite

生物磷灰石中稳定同位素和稀土元素分配的实验校准

• 批准号: 1251443
• 负责人: Matthew Kohn
• 金额: $ 14.28万
• 依托单位: Boise State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-05-15 至 2016-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1251443&HistoricalAwards=false
• 关键词: Experimental; calibration; stable; isotope; REE

Technical description:The geochemistry of biogenic calcium phosphate (bioapatite) is widely used in studies of paleoclimatology, paleoecology, paleoceanography, anthropology/archeology, fossil forensics, geochronology, and tooth caries. Many such endeavors are compromised by poor understanding of the fractionation of stable isotopes of oxygen and carbon in structural carbonate (CO3), and partitioning of rare-earth elements (REE) between bioapatite and aqueous solutions. Stable isotope fractionations and REE partition coefficients will be measured by synthesizing bioapatite in isotopically- and chemically- characterized solutions at temperatures ranging from 10 to 60 °C. Particular emphasis will be placed on identifying the crystallographic site of CO3 substitution as a control on isotope fractionations, calibrating spectroscopic measurements of tooth chemistry, and characterizing particle sizes and surface areas to distinguish intracrystalline vs. adsorption partition coefficients for REE. Time-series experiments will be conducted to ensure close approach to equilibrium, and past experimental methods will be reproduced for improved particle size characterization and comparison to new chemical and isotopic data. Non-technical/Broader impacts:This grant funds a comprehensive calibration of the geochemical behavior of bioapatite - the mineral that constitutes bones and teeth. This work is important for validating past research and improving quantitative interpretations in numerous fields ranging from paleoclimate and paleoceanography to anthropology, forensic discrimination of fossils, geochronology and possibly dental stability. Specifically, we will calibrate methods to determine the carbonate (CO3) content of bioapatite, which strongly controls tooth enamel solubility, and synthesize bioapatites with different CO3 contents. The tendency for bioapatite to accumulate lanthanide-group elements and the heavy isotopes of oxygen and carbon will be calibrated and compared with sparse previous measurements. These data will inform past interpretations of modern tooth and fossil geochemistry and improve targeting of future studies involving modern and fossil teeth. Educational outreach includes research training for a graduate student, and development of undergraduate research for underrepresented groups. Additional training includes development of mentorship skills for a young female research scientist. Boise State serves a large proportion of returning and part-time students with an average undergraduate age of 27. Thus, research and education activities impact a different demographic than at most other universities.

技术描述：磷酸盐生物钙（生物磷灰石）的地球化学广泛用于古气候学，古生态学，古启发学，人类学/考古学，化石法医学，地球人工学和牙齿罐装。由于对结构碳酸盐（CO3）中氧和碳的稳定同位素的分馏以及对生物磷灰石和水溶液之间的稀土元素（REE）的分配，许多此类努力受到了损害。稳定的同位素分馏和REE分区系数将通过在10至60°C的温度下在同位素和化学表征的溶液中通过合成生物磷灰石来测量。将特别强调识别二氧化碳取代的晶体学位点作为对同位素分馏的控制，校准牙齿化学的光谱测量，并表征粒径和表面积，以区分REE的晶体内晶体和浓缩吸收分配系数。将进行时间序列实验，以确保对平衡的紧密方法进行，并将重现过去的实验方法，以改善粒径表征并与新的化学和同位素数据进行比较。非技术/更广泛的影响：该赠款资助了生物磷灰石的地球化学行为的全面校准 - 构成骨骼和牙齿的矿物质。这项工作对于验证过去的研究和改善定量解释很重要，从古气候和古介质学到人类学，对化石的法医歧视，地球人工学以及可能的牙齿稳定性，这些领域的定量解释很重要。具体而言，我们将校准方法来确定生物磷灰石的碳酸盐（CO3）含量，该方法强烈控制了牙釉质的溶解度，并合成具有不同CO3含量的生物磷灰石。生物磷灰石积累灯笼组元素以及氧气和碳的重量同位素的趋势将被校准，并将其与先前的稀疏测量值进行比较。这些数据将为过去对现代牙齿和化石地球化学的解释提供信息，并改善涉及现代和化石牙齿的未来研究的靶向。教育外展活动包括为研究生的研究培训，以及为代表性不足的群体开发本科研究。其他培训包括为年轻的女性研究科学家发展心态技能。博伊西州立大学为27岁平均本科生的返回和兼职学生提供了很大一部分。研究和教育活动影响与大多数其他大学不同。