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

对沉积颗粒大小和形状的自动分析可以有力地用于了解地球深层地质记录中尘埃的保存方式，测试深层地质时期有争议的冰川作用假设，记录不同气候条件下现代河流系统的风化作用如何用于开发古代气候的定量重建，以及记录与人类引起的景观变化有关的沉积物积聚如何改变现代湖盆。这些研究项目的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，这些研究项目将由俄克拉何马大学的研究人员使用由该奖项资助的激光粒度分析系统进行研究。这些项目涉及与地球化学家和气候建模者等合作，他们依靠沉积物输入的信息来进一步了解。获得最先进的颗粒尺寸和成像分析能力将使地质学、相关科学和工程领域的学生、博士后科学家和教师研究人员能够扩展各种研究工作的能力。本科生和研究生将通过与论文相关的工作来接触仪器。学生将接受有关仪器的训练，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何马大学的本科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，该仪器将被少数民族中学生stem夏令营和中学科学教师在职教师专业发展培训研讨会的参与者使用。具体来说，该合同将资助俄克拉何马大学购买激光粒度分析仪（LPSA）和图像分析系统，用于沉积地质学、古气候学和其他应用。LPSA将通过替换过时的无法使用的仪器来加速和扩展研究人员的能力。LPSA使用激光衍射来评估晶粒尺寸，其中由流体中的颗粒引起的光散射产生体积百分比尺寸分布。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1-3000（+）ìm的地质材料特别有用。用于自动颗粒形状分析的仪器是一种新兴的能力，它采用高端显微镜系统，可以对单个颗粒（干或湿分散体）进行成像，包括形状表征和聚集体检测。在100 -1000秒的粒子上快速捕获定量数据，包括透明度和形状属性。颗粒大小和形状分析是非破坏性的，将使俄克拉何马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)从上古生界石灰岩中提取的硅酸盐矿物组分（大气尘埃），以约束大气环流（包括季风环流）和气溶胶的生物地球化学效应；2)疑似冰接触和前冰川沉积物，以检验热带泛古大陆有争议的高地冰川作用假说；3)来自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（用于代理开发）。4)通过对二叠纪红层的分解来验证晚古生代黄土大范围沉积假说；5)利用非洲坦噶尼喀湖的现代湖泊沉积物来验证土地利用变化对沿海地区沉积的影响。

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.