Collaborative Research: Defining the role of heterogeneous lithology in bedrock incision and terrace formation in the Buffalo National River, Arkansas

合作研究：确定异质岩性在阿肯色州布法罗国家河基岩切割和阶地形成中的作用

• 批准号: 1325022
• 负责人: Amanda Keen-Zebert
• 金额: $ 31.28万
• 依托单位: Murray State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-15 至 2013-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1325022&HistoricalAwards=false
• 关键词: Collaborative; Research; Defining; role; heterogeneous

This research will contribute to understanding how landscapes in low topography settings respond to changes in base level (i.e. sea level). These processes are central to interpreting spatial and temporal variation in sediment storage and erosion and have implications for understanding soil loss, pollutant sequestration in soils and floodplains, and flood attenuation over long timescales. The results will also facilitate reconstructions of the changes in the Earth's surface in the mid-continent of North America which can provide baseline information from pre-European human landscapes with which to contextualize modern human impacts and thus guide restoration and management.Through the use of geochronology, field observation, topographic analysis, and GIS we will investigate unresolved problems in geomorphology regarding the impact of variations in lithology on fluvial processes, specifically how lithology impacts bedrock valley and unpaired terrace formation. This project seeks to bring together understanding of processes at variable scales to determine the drivers of river incision in a mid-continent setting south of the glacial limit and to determine whether incision of the Buffalo National River valley has been driven by climate change, base level fall, local processes operating at the scale of the meander, or a combination thereof. The outcomes of this work will improve reconstructions of past landscapes including changes in the hydrologic cycle south of the glacial limit in North America, how bedrock rivers change over time, and how the sedimentary record is created and preserved in caves and alluvial terraces.

这项研究将有助于理解低地形环境下的景观如何响应基准面(即海平面)的变化。这些过程是解释泥沙储存和侵蚀的时空变化的中心，并对理解土壤流失、污染物在土壤和洪泛平原中的固持以及洪水在长时间尺度上的衰减具有重要意义。这些结果还将有助于重建北美中部大陆地球表面的变化，这可以提供欧洲以前人类景观的基线信息，结合现代人类影响，从而指导恢复和管理。通过使用地质年代学、野外观测、地形分析和地理信息系统，我们将研究地貌中关于岩性变化对河流形成的影响的悬而未决的问题，特别是岩性如何影响基岩山谷和未配对的阶地形成。该项目力求将对不同尺度的过程的理解结合起来，以确定冰川界限以南的中大陆背景下河流切割的驱动因素，并确定布法罗国家河谷的切割是由气候变化、基准面下降、曲流河规模的当地过程还是两者的组合驱动的。这项工作的成果将改进过去景观的重建，包括北美冰川界限以南的水文循环的变化，基岩河流随着时间的变化，以及如何在洞穴和冲积阶地中创建和保存沉积记录。