RUI: Fan-pediments in the Southern Blue Ridge Province

RUI：南蓝岭省的扇形山墙饰

• 批准号: 9105041
• 负责人: Hugh Mills
• 金额: $ 8万
• 依托单位: Tennessee Technological University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-06-15 至 1993-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9105041&HistoricalAwards=false
• 关键词: RUI; Fan; pediments; Southern; Blue

Fan-shaped features (fans) in the southern Blue Ridge province are essentially mantled pediments. The mantles, ranging in thickness from 1 to 30 m, consist of diamictons (probably debris flows) and alluvium, and commonly is separated from underlying metamorphic bedrock by a layer of saprolite. Rather than the depositional mechanisms that have been the focus of previous studies of Blue Ridge fans, the thrust of this study is to understand these landforms in the light of previous research on pediments in arid and semiarid regions. Fans in five areas will be mapped using aerial photographs and soil properties to delineate terraces of different ages; standard soil-development indices will be used to estimate ages of the terraces. Seismic refraction and reflection as well as drilling will be used to determine sediment and saprolite thickness and subsurface relief on terraces of different ages. In order to ascertain factors necessary for fan formation, areas with fans will be compared with other areas in the Blue Ridge lacking fans with respect to piedmont and basin morphometry, lithology, soils, and maximum clast size. A hypothesis to be tested is that fans occur only where uplands occur only where uplands supply great numbers of large boulders to the mountain piedmont.

蓝岭省南部的扇形地貌（扇子）本质上是带披肩的山墙饰。 地幔厚度从 1 到 30 m 不等，由硅藻土（可能是泥石流）和冲积层组成，通常通过一层腐泥土与下面的变质基岩分开。 本研究的重点不是先前蓝岭扇研究的重点是沉积机制，而是根据先前对干旱和半干旱地区山墙的研究来了解这些地貌。 将使用航空照片和土壤特性绘制五个区域的扇形图，以描绘不同年龄的梯田；标准土壤发育指数将用于估计梯田的年龄。 地震折射和反射以及钻孔将用于确定不同年龄阶地的沉积物和腐泥土厚度以及地下地形。 为了确定扇形成所需的因素，将在山前和盆地形态、岩性、土壤和最大碎屑尺寸方面将有扇的区域与蓝岭缺乏扇的其他区域进行比较。 需要检验的一个假设是，风扇仅在高地出现的地方出现，只有在高地向山麓提供大量巨石的地方才会出现。