Acquisition of Automated Particle Size and Shape Analysis for Research and Education in Sedimentology, Paleoclimate, and Related Geoscience

获取自动粒度和形状分析，用于沉积学、古气候和相关地球科学的研究和教育

• 批准号: 1418716
• 负责人: Gerilyn Soreghan
• 金额: $ 17.05万
• 依托单位: University of Oklahoma Norman Campus
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2016-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1418716&HistoricalAwards=false
• 关键词: Acquisition; Automated; Particle; Size; Shape

Automated analyses of the sizes and shapes of sedimentary particles can be used in powerful ways to understand how dust preserves in Earth's deep geological record, to test controversial hypotheses of glaciation during deep geological time, document how weathering in modern river systems in different climates may be used to develop quantitative reconstructions of ancient climates, and to document how sediment accumulation linked to human-induced landscape changes may modify modern lake basins. These research projects are unified by their focus on exploring how sedimentary systems inform our understanding of climate change and landscape change, and will be pursued by researchers at the University of Oklahoma using a laser particle size analysis system funded by this award. These projects involve collaboration with, e.g., geochemists and climate modelers, who rely on information from sediment inputs to furthering our understanding. Acquisition of state-of-the-art particle size- and imaging analysis capabilities will expose students, post-doctoral scientists and faculty researchers in geology, allied sciences, and engineering to expanded capabilities in various research endeavors. Undergraduate and graduate students will be exposed to the instrumentation through thesis-related work. Students will be trained on the instrument and gain hands-on experience in acquiring, analyzing, and interpreting their own data independently. The researchers and colleagues will integrate student use of this new equipment, as well as research results enabled by it, in coursework at University of Oklahoma, in undergraduate and graduate classes. Finally, to maximize the effects of this instrument acquisition on broadening participation of underrepresented groups in experiential learning with state-of-the-art analytical tools, the instrumentation will be used by participants in a STEM-based summer camp for minority middle school students, and an in-service teacher professional development training workshop for middle school science teachers.Specifically, this award funds the acquisition of a laser particle size analyzer (LPSA) and image analysis system for sedimentary geology, paleoclimatology, and other applications at the University of Oklahoma. The LPSA will accelerate and extend the researchers' capabilities by replacing an obsolete instrument that is unserviceable. LPSA assesses grain size using laser diffraction, wherein light scatter induced by particles in a fluid produces a volume-percent size distribution. This is a rapid and time-tested means to measure a range of sizes simultaneously, and is particularly useful for geologic materials of 1-3000(+) ìm. Instruments for automated grain shape analysis are an emerging capability, and employ a high-end microscope system enabling imaging of individual particles (dry or wet dispersions), including shape characterization and detection of aggregates. Quantitative data are captured on 100s-1000s of particles rapidly, including transparency as well as shape attributes. Particle size and shape analysis is non-destructive, and will enable rapid progress on an array of current and planned geological research at University of Oklahoma. These projects include analyses of: 1) the silicate mineral fraction (atmospheric dust) extracted from Upper Paleozoic limestone, to constrain atmospheric circulation (including monsoonal circulation), and biogeochemical effects of aerosols, 2) suspected ice-contact and proglacial deposits to test the controversial hypothesis of upland glaciation in tropical Pangaea, 3) modern fluvial sediments from end-member climates to assess climate controls on physical and chemical weathering (for proxy development), 4) disaggregated Permian redbeds to assess the hypothesis of widespread deposition of loess during the late Paleozoic, and 5) modern lacustrine sediments from Lake Tanganyika (Africa) to assess impacts of land-use changes on sedimentation in littoral regions.

对沉积颗粒的大小和形状的自动分析可以以强有力的方式用于了解尘埃如何保存在地球的深层地质记录中，测试有争议的深层地质时期冰川作用假设，记录不同气候下现代河流系统的风化如何用于定量重建古代气候，并记录与人类引起的景观变化有关的沉积物积累如何改变现代湖泊盆地。这些研究项目是统一的，其重点是探索沉积系统如何告知我们对气候变化和景观变化的理解，并将由俄克拉荷马州大学的研究人员使用该奖项资助的激光粒度分析系统进行研究。这些项目涉及与以下方面的合作：地球化学家和气候建模者，他们依靠沉积物输入的信息来加深我们的理解。国家的最先进的粒度和成像分析能力的收购将暴露在地质学，相关科学和工程的学生，博士后科学家和教师研究人员在各种研究工作的扩展能力。本科生和研究生将通过论文相关的工作接触到仪器。学生将接受仪器培训，并获得独立获取，分析和解释自己数据的实践经验。研究人员和同事们将在俄克拉荷马州大学的本科生和研究生课程中整合学生对这种新设备的使用，以及由此产生的研究成果。最后，为了最大限度地发挥这一仪器采购的影响，扩大代表性不足的群体在使用最先进的分析工具进行体验式学习方面的参与，参与者将使用仪器为少数民族中学生举办基于STEM的夏令营，并为中学科学教师举办在职教师专业发展培训讲习班。该合同资助俄克拉荷马州大学购置用于沉积地质学、古气候学和其他应用的激光粒度分析仪（LPSA）和图像分析系统。LPSA将通过更换无法使用的过时仪器来加速和扩展研究人员的能力。LPSA使用激光衍射评估粒度，其中由流体中的颗粒引起的光散射产生体积百分比粒度分布。这是一种快速且经过时间考验的方法，可以同时测量一系列尺寸，对于1-3000（+）μ m的地质材料特别有用。用于自动化颗粒形状分析的仪器是一种新兴的能力，并采用高端显微镜系统，能够对单个颗粒（干或湿分散体）进行成像，包括形状表征和聚集体检测。可快速捕获100 - 1000个颗粒的定量数据，包括透明度和形状属性。粒度和形状分析是非破坏性的，将使俄克拉荷马州大学当前和计划中的一系列地质研究取得快速进展。这些项目包括分析：1）硅酸盐矿物部分（大气粉尘）从上古生界石灰岩中提取，以限制大气环流（包括季风环流）和气溶胶的地球化学效应，2）疑似冰接触和冰前沉积物，以检验热带盘古大陆高地冰川作用的有争议的假设，3）端元气候的现代河流沉积物，以评估气候对物理和化学风化的控制（用于代用开发），4）分解的二叠纪红层，以评估晚古生代黄土广泛沉积的假设，5）坦噶尼喀湖（非洲）现代湖泊沉积物，以评估土地利用变化对沿岸的沉积的影响。