EAR-PF: Using distributions of channel geometry and channel belt properties to distinguish meandering and braided fluvial deposits in the rock record

EAR-PF：利用河道几何形状和河道带特性的分布来区分岩石记录中的曲流和辫状河流沉积物

• 批准号: 1952814
• 负责人: Tian Dong
• 金额: $ 17.4万
• 依托单位: Dong, Tian Y
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1952814&HistoricalAwards=false
• 关键词: EAR; PF; Using; distributions; channel

An NSF EAR Postdoctoral Fellowship has been granted to Dr. Tian Dong to carry out research and education plans at the University of Texas at Austin under the mentorship of Dr. Timothy Goudge. This project will study the distinctions between the two dominant river morphologies observed on Earth: single-thread and braided patterns. Distinguishing between these river types is straightforward in the modern environment as they can be directly observed or predicted using hydrological data. However, distinguishing channel patterns in the sedimentary rock record has proven more difficult, as only remnants of the river channels are preserved and they only account for a small fraction of the overall record. Identifying channel patterns in geologic records is important for predicting the quality and heterogeneity of groundwater and hydrocarbon reservoirs. Through this project, a new set of metrics will be developed for distinguishing river types using distributions of the dimensions of river channels and channel belts (i.e., collections of channel deposits from the same river at different times), measured from modern rivers on Earth using remote sensing data. These metrics will then be interpreted in the context of distinguishing between river types in the ancient rock record, with the anticipated findings relevant for the security of energy and water resources in the United States and related industries. This project also aims to promote participation of underrepresented groups in STEM fields at all levels (K-12 and undergraduate) through outreach programs such as GeoFORCE and research opportunities at the University of Texas at Austin.Formation of the two main river morphologies, single-thread and braided patterns can be relatively well predicted in modern environments using hydraulic variables of channel slope, width, depth, and water discharge. However, recognition of channel patterns in the rock record is difficult because only remnants of the original river channels are preserved. Since hydraulic variables such as slope and discharge cannot be measured directly in rock formations, this work will rely on geologic proxies. In addition to the significance of distinguishing river types to assess subsurface reservoir quality, this distinction is important for testing the hypothesis that whether single-thread rivers were rare prior to the arrival of land plants in the Silurian (~415 to 445 Ma). Previous studies have reconstructed the above four hydraulic variables to distinguish channel patterns in the rock record, but such results have uncertainties that range up to an order of magnitude due to compounded calculation errors. This study proposes to develop new diagnostic metrics using distributions of hydraulic variables and channel belt properties (e.g., width and radius of curvature), measured from modern fluvial systems worldwide via remote sensing techniques, with the ultimate aim for distinguishing channel types in the rock record. Specifically, we aim to test the hypothesis that braided and single-thread rivers have distinct distributions of channel geometry and channel belt properties as supported by theories on river branching. We anticipate that the results of this study will be widely applicable, as geometry variables, such as width and depth, and channel belt width are easily measurable or can be reconstructed with minimum calculation steps across observational length scales, from outcrops to seismic images, timescales, from modern systems to ancient sedimentary deposits, and across localities, from Earth to other planets. This project received co-funding from the Geomorphology and Land-use Dynamics program in the Earth Science division.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.

在蒂莫西·古德（Timothy Goudge）博士的指导下，已经授予了田东博士在德克萨斯大学奥斯汀分校的研究和教育计划的NSF耳朵博士后奖学金。该项目将研究地球上观察到的两个主要河流形态的区别：单线程和编织模式。在现代环境中，区分这些河流类型非常简单，因为可以直接观察或使用水文数据预测它们。但是，由于仅保留了河道的残余，因此在沉积岩石记录中区分频道模式已被证明更加困难，并且仅占整体记录的一小部分。识别地质记录中的通道模式对于预测地下水和碳氢化合物储层的质量和异质性很重要。通过该项目，将开发一组新的指标，用于使用河道和通道带的尺寸分布（即不同时间的同一条河流收集河道沉积物的集合），以使用遥感数据来衡量。然后，这些指标将在区分古代岩石记录中的河流类型的背景下进行解释，预期的发现与美国及相关行业的能源和水资源安全有关。该项目还旨在通过宣传计划（K-12和本科生）在德克萨斯大学奥斯汀大学的地理咖啡和研究机会等宣传计划中促进代表性不足的群体的参与。在现代环境中，在现代环境中可以很好地预测到水文和水平的传播，诸如德克萨斯大学奥斯汀分校的形式，单读和编织的模式可以相对良好地预测。但是，很难识别岩石记录中的通道模式，因为仅保留原始河道的残余物。由于无法直接在岩层中测量液压变量，例如斜坡和排放，因此这项工作将依赖于地质代理。除了区分河流类型以评估地下储层质量的重要性外，这种区别对于检验以下假设很重要：假设单线河流是否在陆地植物到达志留纪（〜415至445 mA）之前是否很少见。先前的研究已重建了以上四个液压变量，以区分岩石记录中的通道模式，但是由于复合的计算误差，这种结果的不确定性范围为数量级。这项研究建议使用液压变量和通道皮带特性的分布（例如，曲率的宽度和半径）开发新的诊断指标，该分布是通过遥感技术在全球范围内的现代河流系统中测量的，其最终目的是区分摇滚记录中的通道类型。具体而言，我们旨在检验以下假设：编织和单线程河流具有河道几何形状和通道皮带特性的不同分布，并由河流分支上的理论支持。我们预计，这项研究的结果将是广泛适用的，因为几何变量（例如宽度和深度）以及通道皮带宽度很容易测量，或者可以通过跨观测长度尺度的最小计算步骤重建，从露头到地震图像，从现代系统到整个地方，从地球上，从地球上到地球，从地球上到其他计划，从地震图像到地震图像。该项目获得了地球科学部的地貌和土地利用动力学计划的共同资助。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛的影响评估标准通过评估来获得支持的。

项目成果

Quantitative relationships between river and channel-belt planform patterns

• DOI: 10.1130/g49935.1
• 发表时间: 2022-06-13
• 期刊: GEOLOGY
• 影响因子: 5.8
• 作者: Dong, Tian Y.;Goudge, Timothy A.
• 通讯作者: Goudge, Timothy A.