Collaborative Research: Processes Driving Rock Uplift and Flexural Deformation following Convergent Tectonics: The Fluvial Terrace Record, Ebro Basin, Spain

合作研究：聚合构造后驱动岩石隆起和弯曲变形的过程：西班牙埃布罗盆地河流台地记录

• 批准号: 0088601
• 负责人: Eric McDonald
• 金额: $ 15万
• 依托单位: Nevada System of Higher Education, Desert Research Institute
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-02-01 至 2005-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0088601&HistoricalAwards=false
• 关键词: Collaborative; Research; Processes; Driving; Rock

Lewis 0088714McDonald 0088601Establishing dynamic links between rock uplift and long-term patterns and rates of fluvial incision away from plate margins is a major contemporary challenge in tectonic geomorphology. We are engaged in a multifaceted project that addresses fundamental questions about how mountainous topography and fluvial systems evolve following active crustal shortening. The Spanish Pyrenees and adjacent Ebro Basin comprise an outstanding locality for isolating processes that drive rock-uplift (or subsidence) in orogens where active compression and crustal thickening have ceased. A marked feature of the Ebro Basin is the striking variation in stream incision into ~25 million year old sedimentary rocks. Incision is minimal along the axis of the basin, but reaches more than 1000 m in the south-central Pyrenees. Our data suggest that long-term patterns and rates of fluvial incision in ranges flanking the Ebro Basin are driven by intraplate phenomena, which form the three competing hypotheses we are testing: Streams in this region incise in response to one, or more, of the following mechanisms: (1) rock uplift by isostatic response to removal of mass from the orogen and adjacent foreland basin; (2) rock uplift driven by upwelling of hot, buoyant asthenosphere perhaps related to adjacent, active crustal extension and volcanism; (3) regional base level lowering, perhaps related to the Messinian salinity crisis, Quaternary eustatic sea level changes, or both. We are developing a precise chronostratigraphy (based on radiocarbon, luminescence, and cosmogenic nuclide dating and soils) of selected stream terraces in the Ebro Basin for which spatial and temporal rates of fluvial incision can be reconstructed. Results will be used to generate a conceptual model for the processes that drive rock-uplift (or subsidence) in orogens where active crustal thickening has ceased. Our multidisciplinary approach requires expertise in structural geology, soil stratigraphy, geochronology, tectonic geomorphology, geodynamic modeling, and regional geology. We focus on the central Pyrenees for this work, but our methodology has direct application to both modern and ancient mountain ranges throughout the world.

刘易斯0088714麦克唐纳0088601建立动态联系之间的岩石隆起和长期模式和河流切割远离板块边缘的速度是一个主要的当代挑战在构造地貌学。 我们正在进行一个多方面的项目，解决有关山区地形和河流系统如何在地壳缩短后演变的基本问题。 西班牙比利牛斯山和邻近的埃布罗盆地是一个突出的孤立过程的地方，这些过程驱动造山带中的岩石隆起（或沉降），在造山带中，主动挤压和地壳增厚已经停止。 埃布罗盆地的一个显著特征是河流对约2500万年前的沉积岩的切割变化显著。 切口是最小的沿着盆地的轴，但达到超过1000米，在比利牛斯山脉中南部。 我们的数据表明，埃布罗盆地两侧山脉河流下切的长期模式和速率是由板内现象驱动的，这形成了我们正在检验的三个相互竞争的假设：该地区河流的下切响应于以下机制中的一个或多个：（1）地壳均衡响应于造山带和邻近前陆盆地的物质迁移而引起的岩石抬升;（2）热的、有浮力的软流层上涌驱动的岩石隆升，可能与邻近的、活动的地壳伸展和火山作用有关：（3）区域基准面下降，可能与梅西尼亚盐度危机、第四纪海平面变化或两者有关。 我们正在开发一个精确的年代地层学（基于放射性碳，发光，宇宙成因核素测年和土壤）的选择流阶地在埃布罗盆地的河流切割的时空速率可以重建。 结果将被用来生成一个概念模型的过程中，驱动岩石隆起（或沉降）的造山带，活跃的地壳增厚已经停止。 我们的多学科方法需要在结构地质学，土壤地层学，地质年代学，构造地貌学，地球动力学建模和区域地质学的专业知识。 我们专注于这项工作的比利牛斯山脉中部，但我们的方法直接适用于世界各地的现代和古代山脉。