Single-grain, multi-parameter characterization of detrital zircon grains to test for the influence of sample processing and sedimentologic processes

对碎屑锆石颗粒进行单颗粒、多参数表征，以测试样品处理和沉积过程的影响

• 批准号: 2121092
• 负责人: Emily Finzel
• 金额: $ 32.61万
• 依托单位: University of Iowa
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2121092&HistoricalAwards=false
• 关键词: Single; grain; multi; parameter; characterization

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).A cornerstone of modern studies of sedimentary rocks is Uranium-Lead isotopic dating of zircon, a common mineral grain in sandstone. However, there is little understanding of how natural and induced bias can influence the outcome of dates. This project will focus specifically on quantifying: 1) the effect of crushing and grinding rocks prior to analysis, and 2) whether variation in hydraulic conditions during deposition influences zircon populations. The work of this project will lead to greater understanding of potential biases and lead to the development of mitigation strategies. This project will support partnerships between academia and government and engagement of pre-service and in-service teachers through a field experience around the Black Hills area in South Dakota.The objectives of this proposal are to test the influence of 1) standard mineral separation processes for detrital zircon studies on grain size, grain shape, and surface microtextures, 2) hydraulic sorting after negating or accounting for the effects of mineral separation with high-n analyses (n=600). A major outcome of this work will be new protocols for provenance studies that integrates traditional, current, and new techniques to clearly document sediment sources and transport history. Our workplan includes: 1) tandem processing of samples using traditional and newer approaches followed by high throughput particle analysis to comprehensively characterize particle size and shape, and 2) single-grain, multi-parameter characterization of detrital zircons to explore for correlations between age groups, grain size/shape, surface morphology, and sediment transport history in a variety of ancient lithofacies representing different hydraulic conditions. This research will elucidate any inherent biases related to mineral separation and depositional energies in sedimentary systems. Being able to decipher the ‘true’ provenance in sedimentary basins will lead to better paleogeographic and sediment dispersal interpretations and tectonic reconstructions.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.

该奖项全部或部分由《2021年美国救援计划法案》（公法117-2）资助。现代沉积岩研究的基石是锆石的铀铅同位素定年法，锆石是砂岩中常见的矿物颗粒。然而，人们对自然和诱导的偏见如何影响约会结果知之甚少。该项目将侧重于量化：1)在分析之前破碎和研磨岩石的影响，以及2)沉积过程中水力条件的变化是否会影响锆石种群。这一项目的工作将有助于加深对潜在偏见的了解，并有助于制定缓解战略。该项目将通过在南达科他州布莱克山地区的实地体验，支持学术界和政府之间的伙伴关系以及职前和在职教师的参与。本提案的目的是测试1)碎屑锆石研究的标准矿物分离过程对粒度、颗粒形状和表面微观结构的影响，2)用高n分析（n=600）否定或考虑矿物分离的影响后的水力分选。这项工作的一个主要成果将是物源研究的新协议，该协议将整合传统、当前和新技术，以清楚地记录沉积物来源和运输历史。我们的工作计划包括：1)利用传统和新型方法对样品进行串联处理，然后进行高通量颗粒分析，全面表征粒度和形状；2)对碎屑锆石进行单粒、多参数表征，探索不同水力条件下不同古岩相中年龄、粒度/形状、表面形态和沉积物输运历史之间的相关性。这项研究将阐明任何与沉积体系中矿物分离和沉积能量有关的固有偏差。能够破译沉积盆地的“真实”物源将有助于更好的古地理和沉积物扩散解释以及构造重建。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。