RUI: Fluvial Terraces: A Tool for Integrating Geomorphic Processes, Climatic and Tectonic Events, and Landscape Development

这是一个地貌调查的河流过程中， 在不同的河流流域之间，构造活动不同的地区， 各盆地的气候随时间而变化。 构造控制 将在高隆升速率地区主导阶地的形成， 气候控制将变得越来越重要， 下降。 我们建议在以下基础上检验这一假设： 三个阶地序列的异同 中等规模的河流发育在泥质砂岩中， 加州北方沿海地区。 目前气候控制量 降水强度和温度都非常相似 对于每个流域，尽管这些参数有所不同， 晚新生代的气候扰动最终导致了 海平面的升降 基层进程 与陆块的相对上升有关， 从最南的河流到最北的河流。 每个流域的实地工作将包括连续的测量 以及侵蚀阶地纵剖面的测绘， 沉积阶地，以及现代河道和河漫滩。 地震折射研究将量化填充深度， 可观察的 阶地形成的年代学将是 受有机物质放射性测年的限制， 冲积沉积物，或者沉积在侵蚀阶地上，或者 在沉积阶地的沉积物中。 这项工作 将允许量化传播的性质和速率 下切填谷的变化 气候和长期构造作用。 结果比较 三条河流，从而分离构造和气候 控制，应允许：1）更好地了解的性质， 河流对变化的响应，2）解释环境 斯特拉特与填方阶地的重要性， 梯段一般，和3）整合， 用景观模型理解地貌过程 进化

This is a geomorphic investigation of fluvial processes in an area in which tectonic activity varies between river basins, and climate varies with time among the basins. Tectonic controls will dominate terrace formation in high uplift rate regions, and climatic controls will gain increasing importance as uplift rate declines. We propose to test this hypothesis on the basis of differences and similarities in the terrace sequences of three moderate size rivers developed in argillaceous sandstone in coastal northern California. Present climatic controls on amount and intensity of precipitation and temperature are very similar for each drainage basin, although these parameters have varied with late Cenozoic climatic perturbations that ultimately drove the rise and fall of eustatic sea level. Base-level processes related to relative rise of the land mass vary by an order of magnitude from the southernmost to the northernmost rivers. Fieldwork in each watershed will consist of continuous surveying and mapping of the longitudinal profiles of erosional terraces, depositional terraces, and the modern channel and floodplain. Seismic refraction studies will quantify depth of fill where not observable. The chronology of terrace formation will be constrained by radiometric dating of organic material from alluvial sediments either resting upon erosional terraces, or within deposits that comprise depositional terraces. This work will allow quantification of the nature and rates of propagation of channel incision and valley in-filling in response to changing climate and long-term tectonism. Comparison of the results for the three rivers, and thus separation of tectonic and climatic controls, should allow: 1) better understanding of the nature of fluvial response to change, 2) interpreting the environmental significance of strath versus fill terraces, and of preserved flights of terraces in general, and 3) integrating an understanding of geomorphic processes with models of landscape evolution.