Collaborative Research: Late Pleistocene paleoclimatology from soil carbonate pendants in the Colorado Plateau.

合作研究：科罗拉多高原土壤碳酸盐下垂物的更新世晚期古气候学。

• 批准号: 1325214
• 负责人: Thure Cerling
• 金额: $ 42.47万
• 依托单位: University of Utah
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-15 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1325214&HistoricalAwards=false
• 关键词: Collaborative; Research; Late; Pleistocene; paleoclimatology

This study will examine isotopic and geochemical records preserved in the laminae of pedogenic carbonate coatings in soils in the Capitol Reef--Boulder Mountain region of the Colorado Plateau. First, the team will check for preservation of stratigraphic order in the laminae of coatings by microscopy, high-resolution X-ray mapping, and Th/U age dating. Coatings that preserve an intact stratigraphy will be micro-sampled for detailed Th/U age transects, stable isotope analysis, and trace element analysis. The team will compare well-dated profiles of stable isotope shifts from coatings collected at various depths below the soil-air interface to reconstruct the timing and magnitude of ecological and climatological changes that occurred over the measured time interval. This study will evaluate the problem of discontinuities in the pendant record which could be related to climate change on orbital time scales. Timing and mechanisms of carbonate formation will be evaluated with in situ soil moisture, respiration, and temperature measurements. Stable isotope analysis of modern and fossil pedogenic carbonate has advanced the understanding of continental paleoclimatology, as well as documenting worldwide ecological shifts. Most stable isotope studies of pedogenic carbonate have sampled soil carbonate at a fairly coarse resolution; only a few have studied the stable isotope record of soil carbonate coatings of the large clasts within a soil horizon. This work will test thick, well-laminated, pedogenic carbonate coatings for records of a meaningful paleoclimate signal in terms of their stable isotope record (13C/12C and 18O/16O) when coatings preserve an intact stratigraphy. If true, and there is some preliminary Th/U and stable isotope data that supports this, then the world's deserts may contain a vast and untapped quantitative archive of past continental climactic and ecological variability. This project is a collaborative effort between the University of Utah and Western State Colorado University. It will enhance education opportunities for both a research institution and an undergraduate institution, and its results will be incorporated into an international course, taught each year at the University of Utah, using stable isotopes as tracers in anthropology, ecology, forensics, geology, hydrology, oceanography, and zoology.

这项研究将检查科罗拉多高原圆顶礁-博尔德山地区土壤成土碳酸盐涂层层中保存的同位素和地球化学记录。首先，研究小组将通过显微镜、高分辨率 X 射线测绘和 Th/U 年龄测定来检查涂层层层中地层秩序的保存情况。将对保留完整地层的涂层进行微取样，以进行详细的 Th/U 年龄横断面、稳定同位素分析和痕量元素分析。该团队将比较在土壤-空气界面以下不同深度收集的涂层的稳定同位素变化的过时剖面，以重建在测量的时间间隔内发生的生态和气候变化的时间和幅度。这项研究将评估悬挂记录中的不连续性问题，这可能与轨道时间尺度上的气候变化有关。将通过原位土壤湿度、呼吸和温度测量来评估碳酸盐形成的时间和机制。对现代和化石成土碳酸盐的稳定同位素分析促进了对大陆古气候学的理解，并记录了全球生态变化。大多数土壤碳酸盐的稳定同位素研究都以相当粗的分辨率对土壤碳酸盐进行了采样。只有少数人研究了土壤层内大型碎屑的土壤碳酸盐涂层的稳定同位素记录。这项工作将测试厚的、分层良好的成土碳酸盐涂层，当涂层保留完整的地层时，根据其稳定同位素记录（13C/12C 和 18O/16O）记录有意义的古气候信号。如果这是真的，并且有一些初步的钍/铀和稳定同位素数据支持这一点，那么世界沙漠可能包含一个巨大的、未开发的过去大陆气候和生态变化的定量档案。该项目是犹他大学和西州立科罗拉多大学之间的合作项目。它将增加研究机构和本科机构的教育机会，其成果将被纳入犹他大学每年教授的国际课程中，使用稳定同位素作为人类学、生态学、法医学、地质学、水文学、海洋学和动物学的示踪剂。