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用来以强有力的方式了解尘埃如何保存在地球深部地质记录中，检验深部地质时期有争议的冰川假说，记录不同气候下现代河流系统的风化作用如何被用来定量重建古代气候，以及记录与人类引起的地形变化有关的沉积物积累如何改变现代湖泊盆地。这些研究项目的重点是探索沉积系统如何影响我们对气候变化和景观变化的理解，这些研究项目是统一的，俄克拉荷马大学的研究人员将使用由该奖项资助的激光粒度分析系统进行研究。这些项目涉及与例如地球化学家和气候模型师的合作，他们依赖来自沉积物输入的信息来加深我们的理解。收购最先进的颗粒尺寸和成像分析能力将使地质学、相关科学和工程学的学生、博士后科学家和教职员工研究人员在各种研究工作中获得更大的能力。本科生和研究生将通过与论文相关的工作接触到这些仪器。学生将接受仪器方面的培训，并获得独立获取、分析和解释自己的数据的实践经验。研究人员和同事将把学生对这种新设备的使用，以及由此带来的研究成果，整合到俄克拉荷马大学本科生和研究生的课程工作中。最后，为了最大限度地发挥这一仪器收购的效果，扩大未被充分代表的群体利用最先进的分析工具进行体验式学习的参与，该仪器将被用于以STEM为基础的少数民族中学生夏令营的参与者，以及为中学科学教师举办的在职教师专业发展培训讲习班。具体地说，该奖项资助俄克拉荷马大学购买沉积地质学、古气候学和其他应用领域的激光粒度分析仪(LPSA)和图像分析系统。LPSA将通过更换不能使用的过时仪器来加速和扩展研究人员的能力。LPSA使用激光衍射来评估颗粒大小，其中由流体中的颗粒诱导的光散射产生体积百分比的尺寸分布。这是一种快速且久经考验的同时测量各种尺寸范围的方法，尤其适用于1-3000(+)？m的地质材料。自动化颗粒形状分析仪器是一种新兴的能力，它采用高端显微镜系统，能够对单个颗粒(干或湿分散)进行成像，包括形状表征和聚集体检测。定量数据被快速捕获在100-1000个颗粒上，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，将使俄克拉荷马大学一系列当前和计划中的地质研究迅速取得进展。这些项目包括：1)分析上古生代石灰岩中提取的硅酸盐矿物成分(大气粉尘)，以限制大气环流(包括季风环流)，以及气溶胶的生物地球化学效应；2)怀疑与冰接触和冰川沉积以检验热带联合古陆高地冰川作用这一有争议的假说；3)来自末端气候的现代河流沉积，以评估气候对物理化学风化的控制(用于替代开发)；4)分解二叠纪红层，以评估晚古生代黄土广泛沉积的假说；和5)来自坦噶尼喀湖(非洲)的现代湖泊沉积，以评估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.