Collaborative Research: Interpreting clumped isotope temperatures and δ18O records from pedogenic carbonate: influence of climate, seasonality, and elevation

合作研究：解释聚集同位素温度和

• 批准号: 1252064
• 负责人: Katharine Huntington
• 金额: $ 16.07万
• 依托单位: University of Washington
• 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: 2013-04-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1252064&HistoricalAwards=false
• 关键词: Collaborative; Research; Interpreting; clumped; isotope

A new isotopic measurement technique of a common geologic material, calcium carbonate, has the potential to reveal how continental temperatures and environmental conditions have changed throughout Earth history. The technique, called clumped isotope thermometry, exploits the temperature-dependent grouping of the heavy isotopes of carbon and oxygen in calcium carbonate. Calcium carbonate bearing soils are relatively common in the terrestrial geologic record and present attractive targets for reconstructing past earth surface environments. However, while the theoretical basis for clumped isotope thermometry is robust, exactly how environmental conditions are reflected in soil carbonate formation temperatures is not well understood. Thus, developing a framework for understanding the environmental factors that influence the timing of carbonate formation is the key to unlocking a potentially rich record of past surface temperatures and enhancing the understanding of Earth?s terrestrial paleoclimates. A team of researchers from Syracuse University and the University of Washington, in collaboration with researchers from the Pontificia Universidad Cátolica de Chile, and the Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales (IANIGLA) in Argentina will conduct a two-year study in and adjacent to the Andes near 30°S latitude to determine how the carbonate clumped isotope thermometer records temperatures in modern to 100,000 year old soils, with a focus on how these methods can be applied to understand Earth's past surface conditions on the continents. The primary research goals are to quantify: 1) the influence of seasonal precipitation, air temperature, and vegetation on the timing and temperature of soil carbonate formation; 2) how well clumped isotope temperatures of Holocene (11,500 year old) soil carbonates and calculated soil water oxygen isotopic values predict modern elevation and the isotopic composition of precipitation; and 3) the impact of signal integration over long (1000 to 10,000 year) timescales by exploring how clumped-isotope temperature varies with soil carbonate age and development stage. The Andean field site is ideal for this study because the 4 km of topographic relief in this area provides a wide range of mean annual and seasonal temperatures. The east and west sides of the Andes also have opposing rainy seasons and gradients in vegetation type and density, enabling this study to tease apart the influence of these factors on clumped isotope temperatures of soil carbonate. This study will support the education and training of two doctoral students in the Earth Sciences as well as foster collaboration among two US universities and their South American counterparts. Components of this research will be used in University and high school teaching via the participation of the PIs in professional development programs for high school teachers in their respective states. The results of this study will be disseminated in scientific journals, professional conferences, the PIs' websites, university courses, and a hands-on activity for the UW's outreach program, Rockin' Out. The project will benefit the broader scientific community by developing a tool that can be applied in many places for paleoclimate and paleoaltimetry research, and potentially change the way researchers interpret stable isotope data for paleosols.

一种新的同位素测量技术，一种常见的地质材料，碳酸钙，有可能揭示整个地球历史的连续温度和环境条件如何变化。该技术称为聚集的同位素温度计，探索了碳酸钙中碳和氧的重量依赖温度的分组。碳酸钙轴承土壤在陆地地质记录中相对常见，并提出了重建过去地面表面环境的有吸引力的目标。但是，虽然簇的同位素温度计的理论基础是稳定的，但在土壤碳酸盐形成温度下的环境条件准确地反映了环境条件。这是开发一个框架来理解影响碳酸盐时机的环境因素，是解锁过去表面温度的潜在丰富记录并增强对地球的陆地古气候的理解的关键。来自锡拉丘兹大学和华盛顿大学的一组研究人员与来自智利庞蒂亚大学的研究人员以及阿根廷阿根廷的阿根廷阿根廷人（Ciencias Ambientales）（ianigla）在阿根廷（Ianigla）的阿根廷人（Ianigla）在阿根廷（Ianigla）的竞争中将对30°s Latitive进行两年的研究，以进行两年的研究，以进行两年的研究。在现代至100,000年的土壤中，重点是如何应用这些方法来了解地球过去的延续状态。主要的研究目标是量化：1）季节性降水，空气温度和植被对土壤碳酸盐形成的时间和温度的影响； 2）全新世（11,500岁）土壤碳酸盐和计算出的土壤水氧同位素值的聚类同位素温度如何预测现代升高和降水的同位素组成； 3）通过探索簇 - 同位素温度如何随土壤碳酸盐年龄和发育阶段而变化，信号整合在长期（1000至10,000年）的时间表上的影响。安第斯野外场地是这项研究的理想选择，因为该地区的4公里地形浮雕提供了广泛的年平均年度和季节性温度。安第斯山脉的东西侧也有相反的雨季和植被类型和密度的梯度，从而使这项研究能够教授这些因素对土壤碳酸盐聚类的同位素温度的影响。这项研究将支持对地球科学的两名博士生的教育和培训，并培养两所美国大学及其南美同行的合作。这项研究的组成部分将在大学和高中教学中通过PI的参与参加各自州的高中教师的专业发展计划。这项研究的结果将在科学期刊，专业会议，PIS的网站，大学课程以及UW的外展计划（Rockin'Out）中传播。该项目将通过开发一种可以在许多地方应用于古气候和古老的研究的工具来使更广泛的科学界受益，并有可能改变研究人员解释古溶质稳定的同位素数据的方式。