The birth of longitudinal rivers in orogenic systems

造山系统纵向河流的诞生

• 批准号: 2245007
• 负责人: Sarah George
• 金额: $ 36.77万
• 依托单位: University of Oklahoma Norman Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-01 至 2026-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2245007&HistoricalAwards=false
• 关键词: birth; longitudinal; rivers; orogenic; systems

Large river systems in mountain belts exert important controls on erosion, sediment flux to oceans, as well as the distribution and evolution, of species. These rivers are highly mobile systems and understanding the processes that modulate their development and evolution are fundamental questions in earth surface processes. This proposal will address the timing and factors that caused the growth of major longitudinal river systems in the northern Andes Mountains of Colombia by studying the modern and ancient sediment transported by these rivers. Data from this project will form the foundation for a new course at the University of Oklahoma. Exercises will be designed to introduce students to transferable skills including basic coding, plotting, and use of geospatial software. These exercises will be available online (at no charge) for others to use or modify in teaching or research. Additionally, this project will support and train undergraduate and graduate students and a postdoctoral scholar, and continue to enhance collaborations with international scientists. More specifically, this proposal will address growth of the Magdalena and Cauca Rivers in the northern Andes Mountains using combination of modern geomorphology, source characterization, and basin analysis. Geomorphic indices will be used to identify areas of modern drainage instability, and 10Be erosion rates will allow for assessment of along-strike variations of erosion rates over notable knick-points. Unique sediment sources in three sub-parallel mountain ranges (Western, Central, and Eastern Cordilleras) facilitate the use of provenance to track shifts in drainage networks through time. These distinctive sediment source regions will be characterized using provenance proxies on modern river sands. Provenance records will also be obtained in upper Miocene-Pliocene strata. Interbedded volcanic and volcaniclastic materials in the sedimentary intervals of interest will enable development of a robust chronostratigraphy. The refined chronostratigraphic framework and new provenance datasets will allow identification of upstream shifts in drainage networks through time. Integration of modern geomorphic proxies and provenance records will test the principal hypothesis that structural diversion led to the birth of longitudinal rivers in the northern Andes. A subset of the samples will be the basis for a series of teaching modules, which will be publicly available to the broader geoscience community as teaching tools.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.

山区的大型河流系统对侵蚀、向海洋的沉积物通量以及物种的分布和演化具有重要的控制作用。这些河流是高度移动的系统，了解调节其发展和演变的过程是地球表面过程的基本问题。该提案将通过研究哥伦比亚北方安第斯山脉主要纵向河流系统搬运的现代和古代沉积物，探讨造成这些河流系统增长的时间和因素。 该项目的数据将为俄克拉荷马州大学的一门新课程奠定基础。 练习将旨在向学生介绍可转移的技能，包括基本编码，绘图和地理空间软件的使用。 这些练习将在网上提供（免费），供其他人在教学或研究中使用或修改。此外，该项目将支持和培训本科生和研究生以及博士后学者，并继续加强与国际科学家的合作。更具体地说，本提案将结合现代地貌学、水源特征和流域分析，探讨北方安第斯山脉马格达莱纳河和考卡河的增长。地貌指数将被用来确定现代排水不稳定的地区，和10 Be侵蚀率将允许沿显著的缺口点侵蚀率的变化进行评估。独特的沉积物来源，在三个次平行山脉（西部，中部和东部科迪勒拉山脉），便于使用物源跟踪排水网络的变化，通过时间。这些独特的沉积物源区将使用现代河流砂的物源代理的特点。还将在中新世-上新世地层中获得物源记录。感兴趣的沉积层段中的互层火山和火山碎屑物质将能够开发出强大的年代地层学。精细的年代地层框架和新的物源数据集将允许识别排水网络随时间的上游变化。现代地貌代用指标和物源记录的整合将检验构造分流导致北方安第斯山脉纵向河流诞生的主要假设。样本的一个子集将成为一系列教学模块的基础，这些模块将作为教学工具向更广泛的地球科学界公开提供。该奖项反映了NSF的法定使命，并被认为值得通过使用该基金会的知识价值进行评估来支持。和更广泛的影响审查标准。