Quantifying long-term aeolian abrasion rates on hard rock surfaces

量化硬岩表面的长期风蚀率

• 批准号: 2314628
• 负责人: Nathan Brown
• 金额: $ 26.16万
• 依托单位: University of Texas at Arlington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-01-01 至 2026-12-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2314628&HistoricalAwards=false
• 关键词: Quantifying; long; term; aeolian; abrasion

In arid regions, on Earth and on other planets, wind-blown sand erodes and reshapes landscapes. On human timescales, this erosion can be immeasurably small, so it is unclear how long it takes to form these landscapes. This project will use two recent advances in geochemical measurements to measure erosion rates on southern Californian ventifacts, boulders which are eroded by sand blasting during windstorms. Based on these measurements, this project will investigate whether a past shift in climate produced different ventifact erosion rates. These measurements will also test whether erosion by wind-blown sand depends on rock type or height above the ground surface. Several reference rocks will be manually eroded at a known rate and then measured to test whether the predicted erosion rates based on geochemical measurements match the actual, known erosion rates. Finally, this project will create 3-D digital models of all ten studied ventifacts and make them freely available to educators everywhere with an accompanying teaching module. These boulders are rare and difficult to access, so creating photorealistic educational models dramatically increases access to these fascinating geological features. A limited supply of 3-D printed, handheld models will also be provided at no cost to interested classrooms and printing instructions will be posted online.The project goal is to quantify the spatial and temporal evolution of aeolian abrasion rates across the surface of ventifacts using recent advances in optically stimulated luminescence (OSL) and cosmogenic, in situ 10Be and 14C methods. Rates will be measured on lengths ranging from several mm to tens of cm and timescales from decadal to multi-millennial. This project involves five major research tasks: (1) field campaign to two sites in southern California; (2) in situ cosmogenic 14C-10Be exposure age and erosion rate analysis (1 paired 14C-10Be sample per ventifact, totaling 10); (3) OSL depth profile erosion rate analysis of ventifacts (10 OSL depth profiles per ventifact, totaling 100) and manually eroded rock cylinders (3 erosion rates per lithology and 10 lithologies, totaling 30); (4) generation of digital 3-D models from field photographs of 10 ventifacts using structure-from-motion photogrammetry and handheld educational models from 3-D printing along with an accompanying educational video; and (5) presentation of results at conferences and in peer-reviewed journal articles. Project results will demonstrate, for the first time, that luminescence measurements can accurately recover hard rock erosion rates on a mm-scale. Measured rates will benchmark existing but empirically untested abrasion mechanisms.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在干旱地区，在地球上和其他行星上，风吹式沙子侵蚀和重塑景观。在人类时标，这种侵蚀可能很小，因此尚不清楚形成这些景观所需的时间。该项目将使用最近的两个地球化学测量进展来测量南加州的预防措施的侵蚀率，这些巨石在暴风雪期间因沙子爆炸而侵蚀。基于这些测量值，该项目将调查过去气候转变是否产生不同的侵蚀率。这些测量值还将测试遭受风砂的侵蚀是否取决于地面上方的岩石类型还是高度。几个参考岩石将以已知速率手动侵蚀，然后测量以测试基于地球化学测量的预测侵蚀率是否与实际已知的侵蚀率相匹配。最后，该项目将创建所有十个研究的ventifacts的3-D数字模型，并通过随附的教学模块自由地向各地的教育工作者免费使用。这些巨石很罕见且难以进入，因此创建逼真的教育模型大大增加了对这些迷人的地质特征的访问。还将在网上发布有限的3D打印，手持式型号，并将不需要为感兴趣的教室提供，并将在线发布印刷说明。该项目的目标是使用光学刺激的发光（OSL）和COSMEGINIC，sotu and storu cosmogenic，intosu and stitu和14c Mettass和Cosmogenic of Cosegogen和14c Mettaics量化了ventifacts跨越整个ventifacts的空间和时间演化。从几毫米到数十厘米的长度和从十年到多千年到多千年的时间尺度的长度将测量速率。该项目涉及五项重大研究任务：（1）在南加州的两个地点进行现场活动； （2）原位宇宙基因14C-10BE暴露年龄和侵蚀率分析（1个配对14c-10be样本，总计10）； （3）OSL深度曲线曲线侵蚀率分析（每次腔内10个OSL深度剖面，总计100）和手动侵蚀的岩石圆柱体（每个岩性3个侵蚀速率和10个岩性，总计30）； （4）使用3-D打印的摄影测量和手持教育模型以及随附的教育视频的摄影模式和手持教育模型从10个ventifacts的现场照片中产生数字3-D模型； （5）在会议和同行评审的期刊文章中介绍结果。项目结果将首次证明发光测量可以准确地恢复MM尺度上的硬岩石侵蚀率。测得的利率将基准基准现有但在经验上未经测试的磨损机制。该奖项反映了NSF的法定任务，并且使用基金会的知识分子优点和更广泛的影响审查标准，被认为值得通过评估来获得支持。